http://dspace.mediu.edu.my:8181/xmlui/handle/123456789/1 2026-05-25T23:16:26Z http://dspace.mediu.edu.my:8181/xmlui/handle/123456789/8837 Surface Evolution of the Sun's Magnetic Field: A Historical Review of the Flux-Transport Mechanism This paper reviews our attempts to understand the transport of magnetic flux on the Sun from the Babcock and Leighton models to the recent revisions that are being used to simulate the field over many sunspot cycles. In these models, the flux originates in sunspot groups and spreads outward on the surface via supergranular diffusion; the expanding patterns become sheared by differential rotation, and the remnants are carried poleward by meridional flow. The net result of all of the flux eruptions during a sunspot cycle is to replace the initial polar fields with new fields of opposite polarity. A central issue in this process is the role of meridional flow, whose relatively low speed is near the limit of detection with Doppler techniques. A compelling feature of Leighton’s original model was that it reversed the polar fields without the need for meridional flow. Now, we think that meridional flow is central to the reversal and to the dynamo itself. 2013-06-01T00:00:00Z http://dspace.mediu.edu.my:8181/xmlui/handle/123456789/8836 Capa: a produção, o consumo e a qualidade da manga no Brasil 2013-06-01T00:00:00Z http://dspace.mediu.edu.my:8181/xmlui/handle/123456789/8835 Sources of Stellar Energy and the Theory of the Internal Constitution of Stars This is a presentation of research into the inductive solution to the problem on the internal constitution of stars. The solution is given in terms of the analytic study of regularities in observational astrophysics. Conditions under which matter exists in stars are not the subject of a priori suppositions, they are the objects of research. In the first part of this research we consider two main correlations derived from observations: "mass-luminosity" and "period - average density of Cepheids". Results we have obtained from the analysis of the correlations are different to the standard theoretical reasoning about the internal constitution of stars. The main results are: (1) in any stars, including even super-giants, the radiant pressure plays no essential part - it is negligible in comparison to the gaseous pressure; (2) inner regions of stars are filled mainly by hydrogen (the average molecular weight is close to 1/2); (3) absorption of light is derived from Thomson dispersion in free electrons; (4) stars have an internal constitution close to polytropic structures of the class 3/2. The results obtained, taken altogether, permit calculation of the physical conditions in the internal constitution of stars, proceeding from their observational characteristics L, M, and R. For instance, the temperature obtained for the centre of the Sun is about 6 million degrees. This is not enough for nuclear reactions. In the second part, the Russell-Hertzsprung diagram, transformed according to physical conditions inside stars shows: the energy output inside stars is a simple function of the physical conditions. Instead of the transection line given by the heat output surface and the heat radiation surface, stars fill an area in the plane of density and temperature. The surfaces coincide, being proof of the fact that there is only one condition - the radiation condition. Hence stars generate their energy not in any reactions. Stars are machines, directly generating radiations. The observed diagram of the heat radiation, the relation "mass-luminosity-radius", cannot be explained by standard physical laws. Stars exist in just those conditions where classical laws are broken, and a special mechanism for the generation of energy becomes possible. Those conditions are determined by the main direction on the diagram and the main point located in the direction. Physical coordinates of the main point have been found using observational data. The constants (physical coordinates) should be included in the theory of the internal constitution of stars which pretend to adequately account for observational data. There in detail manifests the inconsistency of the explanations of stellar energy as given by nuclear reactions, and also calculations as to the percentage of hydrogen and helium in stars. Also considered are peculiarities of some sequences in the Russell-Hertzsprung diagram, which are interesting from the theoretical viewpoint. 2013-06-01T00:00:00Z http://dspace.mediu.edu.my:8181/xmlui/handle/123456789/8834 Produção e certificação de mudas de videira na França 2: técnica de produção de mudas pela enxertia de mesa A técnica de produção de mudas pela enxertia de mesa é o principal meio de propagação da videira na França. A produção de estacas e borbulhas de qualidade em matrizeiros certificados, aliada ao controle das condições ambientais de estratificação, o tratamento com fitorreguladores e as condições de plantio em viveiro têm permitido a melhoria constante dos índices de pegamento e a produção de mudas com alto padrão de qualidade. As técnicas empregadas nas diferentes etapas da confecção de mudas são apresentadas neste artigo, ao mesmo tempo em que são discutidas as possibilidades de adaptação da tecnologia às condições brasileiras. 2013-06-01T00:00:00Z