9 research outputs found
Potato plant growth and macronutrient uptake as affected by soil tillage and irrigation systems
An Observational Overview of Solar Flares
We present an overview of solar flares and associated phenomena, drawing upon
a wide range of observational data primarily from the RHESSI era. Following an
introductory discussion and overview of the status of observational
capabilities, the article is split into topical sections which deal with
different areas of flare phenomena (footpoints and ribbons, coronal sources,
relationship to coronal mass ejections) and their interconnections. We also
discuss flare soft X-ray spectroscopy and the energetics of the process. The
emphasis is to describe the observations from multiple points of view, while
bearing in mind the models that link them to each other and to theory. The
present theoretical and observational understanding of solar flares is far from
complete, so we conclude with a brief discussion of models, and a list of
missing but important observations.Comment: This is an article for a monograph on the physics of solar flares,
inspired by RHESSI observations. The individual articles are to appear in
Space Science Reviews (2011
Ensino da astronomia no Brasil: educação formal, informal, não formal e divulgação científica
High Spectral Resolution Observation of Decimetric Radio Spikes Emitted by Solar Flares – First Results of the Phoenix-3 Spectrometer
A new multichannel spectrometer, Phoenix-3, is in operation having
capabilities to observe solar flare radio emissions in the 0.1 - 5 GHz range at
an unprecedented spectral resolution of 61.0 kHz with high sensitivity. The
present setup for routine observations allows measuring circular polarization,
but requires a data compression to 4096 frequency channels in the 1 - 5 GHz
range and to a temporal resolution of 200 ms. First results are presented by
means of a well observed event that included narrowband spikes at 350 - 850
MHz. Spike bandwidths are found to have a power-law distribution, dropping off
below a value of 2 MHz for full width at half maximum (FWHM). The narrowest
spikes have a FWHM bandwidth less than 0.3 MHz or 0.04% of the central
frequency. The smallest half-power increase occurs within 0.104 MHz at 443.5
MHz, which is close to the predicted natural width of maser emission. The
spectrum of spikes is found to be asymmetric, having an enhanced low-frequency
tail. The distribution of the total spike flux is approximately an exponential.Comment: Solar Physics, in pres
Educação para as ciências da natureza e matemáticas no Brasil: um estudo sobre os indicadores de qualidade do SPEC (1983-1997)
Formação continuada de profissionais da educação: a busca de integração entre gestão e currículo no cotidiano escolar
Este texto analisa os pressupostos básicos da formação continuada de profissionais da educação e tece algumas considerações iniciais sobre o desenvolvimento do Projeto "A busca de integração entre gestão e currículo no cotidiano escolar", em andamento, na Delegacia de Ensino de Sertãozinho-SP. Os resultados que obtivemos até o presente momento evidenciam que estes profissionais conseguem levantar situações problematizadoras, a partir de seu cotidiano, porém a reflexão crítica e o trabalho coletivo são alvos a serem atingidos
