Spontaneous current-layer fragmentation and cascading reconnection in solar flares: II. Relation to observations

In the paper by B\'arta et al. (arXive:astro-ph:/1011.4035, 2010) the authors addressed some open questions of the CSHKP scenario of solar flares by means of high-resolution MHD simulations. They focused, in particular, on the problem of energy transfer from large to small scales in decaying flare current sheet (CS). Their calculations suggest, that magnetic flux-ropes (plasmoids) are formed in full range of scales by a cascade of tearing and coalescence processes. Consequently, the initially thick current layer becomes highly fragmented. Thus, the tearing and coalescence cascade can cause an effective energy transfer across the scales. In the current paper we investigate whether this mechanism actually applies in solar flares. We extend the MHD simulation by deriving model-specific features that can be looked for in observations. The results of the underlying MHD model showed that the plasmoid cascade creates a specific hierarchical distribution of non-ideal/acceleration regions embedded in the CS. We therefore focus on the features associated with the fluxes of energetic particles, in particular on the structure and dynamics of emission regions in flare ribbons. We assume that the structure and dynamics of diffusion regions embedded in the CS imprint themselves into structure and dynamics of flare-ribbon kernels by means of magnetic-field mapping. Using the results of the underlying MHD simulation we derive the expected structure of ribbon emission and we extract selected statistical properties of the modelled bright kernels. Comparing the predicted emission and its properties with the observed ones we obtain a good agreement of the two.Comment: 7 pages, 5 figure

Suppression of Hydrogen Emission in an X-Class White-Light Solar Flare

We present unique NUV observations of a well-observed X-class flare from NOAA 12087 obtained at Ond\v{r}ejov Observatory. The flare shows a strong white-light continuum but no detectable emission in the higher Balmer and Lyman lines. RHESSI and Fermi observations indicate an extremely hard X-ray spectrum and gamma-ray emission. We use the RADYN radiative hydrodynamic code to perform two type of simulations. One where an energy of 3 x 10^11 erg/cm^2/s is deposited by an electron beam with a spectral index of ~3 and a second where the same energy is applied directly to the photosphere. The combination of observations and simulations allow us to conclude that the white-light emission and the suppression or complete lack of hydrogen emission lines is best explained by a model where the dominant energy deposition layer is located in the lower layers of the solar atmosphere rather than the chromosphere.Comment: 13 page

Comparison of traffic overhead and cable networks high voltage

Diplomová práce je zaměřena na porovnání provozu venkovních a kabelových sítí vysokého napětí. Popisuje náklady provozu sítí vysokého napětí a investiční náročnost výstavby zařízení. Dále analyzuje provoz vysokého napětí a zabývá se také provozně technicko - ekonomickým přínosem distribuční sítě.Katedra elektroenergetiky a ekologieObhájenoThis thesis is focused on the comparison of the operation of high-voltage outdoor and high-voltage cable networks. It describes the cost of operation of high-voltage networks and the investment demands for the construction of installations. Additionally, it analyzes the operation of high voltage and also discusses the technical and economic operational benefits of the distribution network

Runtime support for advanced component concepts

Component-based development has become a recognized technique for building large scale distributed applications. Although the maturity of this technique, there appears to be quite a significant gap between (a) component systems that are rich in advanced features (e.g., component nesting, software connectors, versioning, dynamic architectures), but which have typically only poor or even no runtime support, and (b) component systems with a solid runtime support, but which typically possess only a limited set of the advanced features. In our opinion, this is mainly due to the difficulties that arise when trying to give proper semantics to the features and reify them in development tools and an runtime platform. In this paper, we describe the implementation of the runtime environment for the SOFA 2.0 component model. In particular, we focus on the runtime support of the advanced features mentioned above. The described issues and the solution are not specific only to SOFA 2.0, but they are general and applicable to any other component system aiming at addressing such features.