23,926 research outputs found
Light controlled magnetoresistance and magnetic field controlled photoresistance in CoFe film deposited on BiFeO3
We present a magnetoresistive-photoresistive device based on the interaction
of a piezomagnetic CoFe thin film with a photostrictive BiFeO3 substrate that
undergoes light-induced strain. The magnitude of the resistance and
magnetoresistance in the CoFe film can be controlled by the wavelength of the
incident light on the BiFeO3. Moreover, a light-induced decrease in anisotropic
magnetoresistance is detected due to an additional magnetoelastic contribution
to magnetic anisotropy of the CoFe film. This effect may find applications in
photo-sensing systems, wavelength detectors and can possibly open a research
development in light-controlled magnetic switching properties for next
generation magnetoresistive memory devices.Comment: 5 pages, 4 figures, journal pape
Radiative decay Z_H-> \gamma A_H in the little Higgs model with T-parity
In the little Higgs model with T-parity (LHTM), the only tree-level
kinematically allowed two-body decay of the Z_H boson is Z_H-> A_H H and thus
one-loop induced two-body decays may have a significant rate. We study the
Z_H-> \gamma A_H decay, which is induced at the one-loop level by a fermion
triangle and is interesting as it depends on the mechanism of anomaly
cancellation of the model. All the relevant two- and three-body decays of the
Z_H gauge boson arising at the tree-level are also calculated. We consider a
small region of the parameter space where the scale of the symmetry breaking f
is still allowed to be as low as 500 GeV by electroweak precision data. We
first analyze the scenario of a Higgs boson with a mass of 120 GeV. We found
that the Z_H->\gamma A_H branching ratio can be of the order of a tree-level
three-body decay and may be at the reach of detection at the LHC for f close to
500 GeV, but it may be difficult to detect for f=1 TeV. There is also an
scenario where the Higgs boson has an intermediate mass such that the Z_H-> A_H
H decay is closed, the Z_H-> \gamma A_H gets considerably enhanced and the
chances of detection get a large boost.Comment: 19 pages, 9 figures, 2 table
Rendimento de derruba e extração mecanizada em florestas de terra firme da Amazônia.
bitstream/item/59273/1/CPATU-ComTec46.pd
Balanço de radiação no Perímetro Irrigado Senador Nilo Coelho utilizando técnicas de sensoriamento remoto e Imagens Landsat 5 - TM.
Deste modo, esta pesquisa se propõe a determinar o saldo de radiação, bem como o balanço de ondas curtase de ondas longas, do perímetro irrigado Senador Nilo Coelho, usando-se imagens do Mapeador Temático doLandsat 5. Com os resultados aqui obtidos, serão aplicados procedimentos que possibilitarão estimar os fluxos decalor sensível e de calor latente, através dos quais estimar-se-á a evapotranspiração em base diária no perímetroirrigado supra mencionado
Determinação do albedo do Perímetro Irrigado Senador Nilo Coelho com técnicas de sensoriamento remoto e imagens Landsat 5-TM.
O presente trabalho tem por objetivo a estimativa do albedo de todo o Perímetro Nilo Coelho e adjacências, píxel a pixel, com imagens multiespectrais do Landsat 5 Thematic Mapper
A Complex Network Approach to Topographical Connections
The neuronal networks in the mammals cortex are characterized by the
coexistence of hierarchy, modularity, short and long range interactions,
spatial correlations, and topographical connections. Particularly interesting,
the latter type of organization implies special demands on the evolutionary and
ontogenetic systems in order to achieve precise maps preserving spatial
adjacencies, even at the expense of isometry. Although object of intensive
biological research, the elucidation of the main anatomic-functional purposes
of the ubiquitous topographical connections in the mammals brain remains an
elusive issue. The present work reports on how recent results from complex
network formalism can be used to quantify and model the effect of topographical
connections between neuronal cells over a number of relevant network properties
such as connectivity, adjacency, and information broadcasting. While the
topographical mapping between two cortical modules are achieved by connecting
nearest cells from each module, three kinds of network models are adopted for
implementing intracortical connections (ICC), including random,
preferential-attachment, and short-range networks. It is shown that, though
spatially uniform and simple, topographical connections between modules can
lead to major changes in the network properties, fostering more effective
intercommunication between the involved neuronal cells and modules. The
possible implications of such effects on cortical operation are discussed.Comment: 5 pages, 5 figure
Uma proposta de pesquisa para análise do relacionamento entre inovação e desempenho utilizando a abordagem multidimensional.
Enhanced Ethanol Dehydration with Hydrostable Inorganic Pervaporation Membranes
Membranes which allow water diffusion in favour of other substances can offer increased efficiency in processes to dehydrate ethanol. Silica membranes can perform this selective diffusion, but have mostly been reported for their gas high gas separating ability. This work investigates the effectiveness of carbonised template molecular sieve (CTMSS) membrane to dehydrate ethanol/water mixtures. The silica derived top layer of the membrane was measured at 20nm thickness by XPS sputtering technique. However, the silica enters the porous structure of -alumina layer in excess of 90nm. After 200 minutes of operation, H2O/EtOH selectivity increased to 5.6 from around 1 due to gradual pore filling by adsorbed water and ethanol which contributed to inhibiting ethanol transport. The smaller water molecules were thus favoured in transporting to the permeate side. Total mass flux using a 10% ethanol feed remained constant at around 1.5 kg.m-2.hr-1. Selectivity of up to 9.5 was achieved when azeotropic feed solutions of 95% were used, displaying the potential for this technology for a wide range of ethanol dehydration applications. Pressurising the feed up to 400 kPa doubled the permeate flux, but enhanced the transport of ethanol over water
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