K Discharges
Mostrando 1-12 de 79 artigos, teses e dissertações.
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1. Observação do transporte de sedimentos em suspensão ao longo do Canal Norte do rio Amazonas durante condições de baixa descarga (outubro 2008) / Observation of suspended sediment transport along North Channel of Amazon river during low discharge (October 2008)
The Amazon river, located in northernBrazil, discharges between 80,000 and 250,000 m3s-1 of water onto the adjacent shelf, creating a plume of brackish water that extends hundreds of kilometers away from the river mouth. This river also carries a large amount of fine sediments to the ocean where fluid mud has been found in the topset and upper foreset layers
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/10/2011
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2. Optical and electrical diagnostics of microdischarges at moderate to high pressure in argon
Microdischarges at moderate to high pressure in argon were investigated. A hole opening diameter of 500 µm direct current (dc) microhollow cathode discharges (MHCD) were characterized by electrical measurements and optical emission spectroscopy (OES) for pressures ranging between 90 and 800 Torr and current from 5 to 20 mA. Current-voltage characteristic cu
Brazilian Journal of Physics. Publicado em: 2010-12
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3. Avaliação de impactos ambientais nos tributários do lago Paranoá, Brasília - DF
The high level of urbanization in Distrito Federal in Brazil is contributing to modify the environment particularly the quality of surface water resources. The historical of environment aggression to the Paranoá Lake through urban expansion, land use and land occupation, is studied as environmental changes. In this work, physical-chemistry conditions and ge
Publicado em: 2007
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4. Study of confinement improvement in presence of a MARFE in the HT-7 superconducting tokamak
A new set of actively cooled toroidal double-ring graphite limiters have been developed on the HT-7 tokamk for long pulse operation. In this paper, a Multifaceted asymmetric radiation from the edge (MARFE) phenomena and improved particle confinement induced by a MARFE, characterized by Halpha line emissions drops and the line-averaged density increase have b
Brazilian Journal of Physics. Publicado em: 2006-09
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5. The dynamics of groundwaters in the estuary of the River Itanhaem, the south coast of the State of São Paulo / A dinamica das aguas subterraneas no estuario do Rio Itanhaem, litoral sul do Estado de São Paulo
The present work studied the influence of the tide in the coastal aquifers by identifying hydrodynamic and chemical alterations in the aquifiers. The research was carried out in the Itanhaém river estuary in two localities: in the Sitio de Pesquisa with 7 installed wells situated on the banks of the Acima river, 3,5 km from the ocean, and in the CePeRio - C
Publicado em: 2006
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6. Electron Cyclotron Emission in the TCABR Tokamak: An Experimental Study. / "Emissão Eletrociclotrônica no Tokamak TCABR: Um Estudo Experimental"
In this work, an experimental study of the Electron Cyclotron Emission (ECE) in the TCABR Tokamak, is described. An ECE sweeping heterodyne radiometer, operating in the 50-85 GHz frequency range, was installed, calibrated and used to detect ECE radiation in the second harmonic extraordinary mode from thermal plasma discharges. The noise temperature, amplitud
Publicado em: 2005
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7. Effect of air-oxygen and argon-oxygen mixtures on dielectric barrier discharge decomposition of toluene
One alternative application in the decomposition and destruction of volatile organic compounds (VOCs) by a silent plasma dielectric barrier discharge (DBD) has been successfully accomplished. For this purpose, we have designed and constructed two pairs of cells, of rectangular and circular geometries, 333.96 cm³ each cell, and a similar second pair of 62.25
Brazilian Journal of Physics. Publicado em: 2004-12
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8. Longitudinal magnetic field effect on the electrical breakdown in low pressure gases
The electrical breakdown has been investigated for low-pressure argon and nitrogen discharges under the influence of an external longitudinal magnetic field. Plane-parallel aluminum electrodes (5 cm diameter) separated by a variable distance d (4.0 cm < d < 11.0 cm) were sustained with a dc voltage (0 < V < 1 kV). A Helmholtz coil was used to produce an unif
Brazilian Journal of Physics. Publicado em: 2004-12
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9. Nitriding of AISI 304 stainless steel by PIII in DC and RF toroidal discharges
Plasma immersion ion implantation (PIII) of stainless steels with nitrogen has been successfully used for surface hardening purposes. This process has been carried out inside a toroidal discharge chamber in a DC/RF plasma. The RF plasma was created by one antenna located inside the chamber, diametrically opposite to the DC electrode. The latter is polarized
Brazilian Journal of Physics. Publicado em: 2004-12
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10. Electron density measurements from right-hand cutoff of ECE in the TCABR tokamak
In tokamak machines with low toroidal magnetic fields and high plasma densities, the accessibility conditions impose restrictions to the detection of the Electron Cyclotron Emission (ECE). In these machines, the righthand cutoff condition can be used as an independent method to determine the local electron density from the ECE data in thermal discharges. In
Brazilian Journal of Physics. Publicado em: 2004-12
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11. Modification of plasma polymer films by ion implantation
In this work, thin polymer films were prepared from acetylene and argon radiofrequency (13.56 MHz, 80 W) glow discharges. Post-deposition treatment was performed by plasma immersion ion implantation in nitrogen or helium glow discharges (13.56 MHz, 70 W). In these cases, samples were biased with 25 kV negative pulses. Exposure time to the bombardment plasma,
Materials Research. Publicado em: 2004-09
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12. Plasma resistivity determination in runaway discharges from positive voltage spikes on TCABR tokamak
Plasma resistivity is estimated in runaway discharges on TCABR tokamak from the decay of positive voltage spikes using method developed in I. El Chamaa Neto et al., Phys. Plasmas 7, 2894 (2000). In this regime, the plasma detachment from the limiter is observed experimentally indicating that plasma recombination is the main process of plasma particle losses.
Brazilian Journal of Physics. Publicado em: 2002-03