7,573 research outputs found
Tracking the relationship between euro area equities and sovereign bonds
This paper explores the relationship between stocks and sovereign bonds by means of the asymmetric detrended cross-correlation analysis (ADCCA). Drawing on data from 1999.01 to 2018.09 of the first wave of euro area countries, the full sample is divided into three subsets in accordance with economic and financial features. Some findings arise with striking implications for investors and policymakers. Firstly, empirical results show that cross-correlations differ from country to country, depending on the sub-period under analysis and on the time scale. Secondly, likewise within country estimates, cross-country linkages may point to fragmentation in the euro area with agents moving away from financial assets of lower-rated countries to invest in more robust economies in periods of turmoil. Thirdly, there is evidence of asymmetry since 'flight-to-quality' movements seem to be more relevant than 'flight-to-yield' episodes. Finally, while relationships were globally bidirectional until mid-2007, new causality patterns arose with the financial crisis.info:eu-repo/semantics/publishedVersio
Spin-polarized transport in ferromagnetic multilayered semiconductor nanostructures
The occurrence of inhomogeneous spin-density distribution in multilayered
ferromagnetic diluted magnetic semiconductor nanostructures leads to strong
dependence of the spin-polarized transport properties on these systems. The
spin-dependent mobility, conductivity and resistivity in
(Ga,Mn)As/GaAs,(Ga,Mn)N/GaN, and (Si,Mn)/Si multilayers are calculated as a
function of temperature, scaled by the average magnetization of the diluted
magnetic semiconductor layers. An increase of the resistivity near the
transition temperature is obtained. We observed that the spin-polarized
transport properties changes strongly among the three materials.Comment: 3 pages, 4 figure
Melting temperature of screened Wigner crystal on helium films by molecular dynamics
Using molecular dynamics (MD) simulation, we have calculated the melting
temperature of two-dimensional electron systems on \AA-\AA helium
films supported by substrates of dielectric constants
at areal densities varying from cm to cm. Our results are in good agreement with the available
theoretical and experimental results.Comment: 4 pages and 4 figure
Efeito do regulador vegetal cloreto de clormequat nos componentes da produção e na produtividade do feijoeiro.
O objetivo deste trabalho foi avaliar os efeitos de doses do regulador de crescimento cloreto de clormequat, marca comercial Tuval®, aplicado de forma parcelada, em algumas caracterÃsticas agronômicas e na produtividade do feijoeiro
Doses e formas de aplicação de uréia comum e aditivada no feijoeiro irrigado cultivado em plantio direto.
O objetivo deste trabalho foi avaliar a resposta do feijoeiro irrigado por aspersão, sistema pivô central, cultivado em condições de plantio direto no sistema integração lavourapecuária, à adubação com duas fontes de N, uréia normal e uréia aditivada, duas formas de aplicação, em superfÃcie e incorporada, e quatro doses de N em cobertura, em Latossolo Vermelho distroférrico
Assessment of the potential of tin sulphide thin films prepared by sulphurization of metallic precursors as cell absorbers
In this work, SnxSy thin films have been grown on soda-lime glass substrates by sulphurization of metallic
precursors in a nitrogen plus sulphur vapour atmosphere. Different sulphurization temperatures were tested,
ranging from 300 °C to 520 °C. The resulting phases were structurally investigated by X-Ray Diffraction and
Raman spectroscopy. Composition was studied using Energy Dispersive Spectroscopy being then correlated
with the sulphurization temperature. Optical measurements were performed to obtain transmittance and
reflectance spectra, from which the energy band gaps, were estimated. The values obtained were 1.17 eV for
the indirect transition and for the direct transition the values varied from 1.26 eV to 1.57 eV. Electrical
characterization using Hot Point Probe showed that all samples were p-type semiconductors. Solar cells were
built using the structure: SLG/Mo/SnxSy/CdS/ZnO:Ga and the best result for solar cell efficiency was 0.17%
Mo bilayer for thin film photovoltaics revisited
Thin film solar cells based on Cu(In,Ga)Se2 as an absorber layer use Mo as the back contact.
This metal is widely used in research and in industry but despite this, there are only a few
published studies on the properties of Mo. Properties such as low resistivity and good
adhesion to soda lime glass are hard to obtain at the same time. These properties are dependent
on the deposition conditions and are associated with the overall stress state of the film. In this
report, a study of the deposition of a Mo bilayer is carried out by analysing first single and then
bilayers. The best properties of the bilayer were achieved when the bottom layer was
deposited at 10 × 10−3 mbar with a thickness of 500 nm and the top layer deposited at
1 × 10−3 mbar with a thickness of 300 nm. The films deposited under these conditions showed
good adhesion and a sheet resistivity lower than 0.8
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