5,861 research outputs found
The development of a universal diagnostic probe system for Tokamak fusion test reactor
The Tokamak Fusion Test Reactor (TFTR), the largest such facility in the U.S., is discussed with respect to instrumentation in general and mechanisms in particular. The design philosophy and detailed implementation of a universal probe mechanism for TFTR is discussed
Filamentary fragmentation in a turbulent medium
We present the results of smoothed particle hydrodynamic simulations
investigating the evolution and fragmentation of filaments that are accreting
from a turbulent medium. We show that the presence of turbulence, and the
resulting inhomogeneities in the accretion flow, play a significant role in the
fragmentation process. Filaments which experience a weakly turbulent accretion
flow fragment in a two-tier hierarchical fashion, similar to the fragmentation
pattern seen in the Orion Integral Shaped Filament. Increasing the energy in
the turbulent velocity field results in more sub-structure within the
filaments, and one sees a shift from gravity-dominated fragmentation to
turbulence-dominated fragmentation. The sub-structure formed in the filaments
is elongated and roughly parallel to the longitudinal axis of the filament,
similar to the fibres seen in observations of Taurus, and suggests that the
fray and fragment scenario is a possible mechanism for the production of
fibres. We show that the formation of these fibre-like structures is linked to
the vorticity of the velocity field inside the filament and the filament's
accretion from an inhomogeneous medium. Moreover, we find that accretion is
able to drive and sustain roughly sonic levels of turbulence inside the
filaments, but is not able to prevent radial collapse once the filaments become
supercritical. However, the supercritical filaments which contain fibre-like
structures do not collapse radially, suggesting that fibrous filaments may not
necessarily become radially unstable once they reach the critical line-density.Comment: (Accepted for publication in MNRAS
CONTROLE E DISPUTA PELA DEMOCRACIA NA COMUNICAÇÃO SOCIAL
This article analyzes the current state of the Brazilian media in relation to the influence of the companies that constitute Mass Communication Enterprises in Brazil . On the other hand, observes the participation of the movements for democratizing the media. The paper looks to contribute for the theoretical debate and of perspectives for a better performance on the part of the activists of communitarian communication, as well as the popular movement. The article goes through a bibliographical and documental research, besides the analysis of recent data, looking to evidence the importance of the constitution of democratic public politics for the people empowerment in our country
Detection survey for grapevine rust at the irrigated areas of the São Francisco Valley, Brazil.
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Compton scattering in TFD formalism
In this paper, the cross section for the Compton scattering process at finite
temperature is calculated. Temperature effects are introduced using the
Thermofield Dynamics (TFD) formalism. It is a real-time finite temperature
quantum field theory. Our result shows that thermal effects become relevant as
the temperature increases. A comparison between the TFD and closed-time path
results is presented.Comment: 14 pages, 2 figures, accepted for publication in EPJ
Effects of Hierarchy Rank on Caching Frequency in a Captive Coywolf (Eastern Coyote) Canis latrans × lycaon, Pack
Caching is useful because it ensures a consistent supply of food for animals. However, there is a relative paucity of data concerning which members of canid social units make the most caches. We provide data indicating that dominant members of a captive Coywolf “Eastern Coyote”, (Canis latrans × lycaon) pack did the majority (78%, n = 46 of 59) of caching. Caching is a common activity stereotypically performed by canids, and dominant members of a social unit tend to cache more often
The sediment budget as a management tool: the Shoalhaven Coastal Compartment, southeastern NSW, Australia
Sediment budgets are fundamental approaches in coastal studies for allowing estimates of volumes of sediments entering and exiting a selected area of the coast, resulting in net erosion or accretion of that compartment under consideration. This assessment is crucial for understanding current processes and predicting future effects of sedimentimpact activities, promoting the sustainability of coastal environments over the next centuries. In this paper we present a series of preliminary spatial, sedimentological and geophysical analyses undertaken in order to understand the sources, sinks, transport and pathways for the sediment budget of the Shoalhaven coast, a compartment whose sediment provision is supplied primarily by the Shoalhaven River (draining a catchment of 7,151 km2) and that stretches ~32 km from the rocky headland of Black Head at Gerroa (north) to the Beecroft Peninsula near Currarong (south). Analysis included the use of sub-bottom profiler, ground penetrating radar, RTK-GPS, aerial photographs, satellite images, LiDAR, echosounding, computer modelling, as well as grain size parameters from ~200 sediment (and mineralogy for selected) samples from the estuary, beach and shoreface
Variedades de abacaxi.
Todas as variedades de abacaxi cujo interesse é o fruto, seja para consumo in natura ou para processamento, pertencem à espécie Ananas comosus var. comosus. Alguns clones de Ananas comosus var. erectifolius, Ananas comosus var. ananassoides e Ananas comosus var. bracteatus são cultivados para produção de fibra ou para fins ornamentais. Recentemente, houve grande incremento nestas formas de utilização. A variedade de abacaxi predominantemente cultivada no mundo é a Smooth Cayenne, responsável por cerca de 70% da produção mundial de abacaxi. Contudo, outras variedades como Singapore Spanish, Queen, Red Spanish, Pérola e Perolera são muito cultivadas e difundidas em nível mundial (Leal, 1990). No Brasil, onde a área de plantio em 2002 foi de 62.597 ha, com produção de 1.430.018 mil frutos e rendimento de 22.845 frutos/ha (IBGE, 2003), a variedade mais plantada é a Pérola, responsável por cerca de 80% da produção brasileira de abacaxi havaiano, cujos plantios se concentram no Sudeste do país, principalmente em São Paulo e na região do Triângulo Mineiro.bitstream/item/81569/1/Circular-Tecnica-63-Variedade-Abacaxi-Renato-Cabral-2003.pdfMemória
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