1,431 research outputs found
Inertial forces in the Casimir effect with two moving plates
We combine linear response theory and dimensional regularization in order to
derive the dynamical Casimir force in the low frequency regime. We consider two
parallel plates moving along the normal direction in dimensional space. We
assume the free-space values for the mass of each plate to be known, and obtain
finite, separation-dependent mass corrections resulting from the combined
effect of the two plates. The global mass correction is proportional to the
static Casimir energy, in agreement with Einstein's law of equivalence between
mass and energy for stressed rigid bodies.Comment: 9 pages, 1 figure; title and abstract changed; to appear in Physical
Review
Quantum radiation pressure on a moving mirror at finite temperature
We compute the radiation pressure force on a moving mirror, in the
nonrelativistic approximation, assuming the field to be at temperature At
high temperature, the force has a dissipative component proportional to the
mirror velocity, which results from Doppler shift of the reflected thermal
photons. In the case of a scalar field, the force has also a dispersive
component associated to a mass correction. In the electromagnetic case, the
separate contributions to the mass correction from the two polarizations
cancel. We also derive explicit results in the low temperature regime, and
present numerical results for the general case. As an application, we compute
the dissipation and decoherence rates for a mirror in a harmonic potential
well.Comment: Figure 3 replaced, changes mainly in Sections IV and V, new appendix
introduced. To appear in Physical Review
Molecular Dynamics of Film Formation of Metal Tetrasulfonated Phthalocyanine and Poly Amidoamine Dendrimers
We performed molecular dynamics computer simulations to elucidate the behavior and properties of the metal tetrasulfonated phthalocyanine molecule and the poly(amidoamine) dendrimers in self-assembly depositions, respectively, on poly(allylamine hydrochloride) polymer and on film formed by metal tetrasulfonated phthalocyanine with poly(allylamine hydrochloride). Important physical properties of phthalocyanines were obtained such as the kinetic energy and temperature in situ. By the semiempirical model, we also obtained the UV-Vis absorption spectrum of the film formed by cobalt tetrasulfonated phthalocyanine deposited on poly(allylamine hydrochloride). We performed a study with poly(amidoamine) dendrimers on their deposition time on metal tetrasulfonated phthalocyanine, poly(allylamine hydrochloride) film, and we show the relationship of deposition time with the electrical charge and molecular mass of phthalocyanines. The deposition times of the dendrimers, as a function of their mass, were also elucidated
Second Life of Lithium-Ion Batteries of Electric Vehicles: A Short Review and Perspectives
Technological advancement in storage systems has currently stimulated their use in miscellaneous applications. The devices have gained prominence due to their increased performance and efficiency, together with the recent global appeal for reducing the environmental impacts caused by generating power or by combustion vehicles. Many technologies have been developed to allow these devices to be reused or recycled. In this sense, the use of lithium-ion batteries, especially in electric vehicles, has been the central investigative theme. However, a drawback of this process is discarding used batteries. This work provides a short review of the techniques used for the second-life batteries of electric vehicles and presents the current positioning of the field, the steps involved in the process of reuse and a discussion on important references. In conclusion, some directions and perspectives of the field are shown
Produção e qualidade da serrapilheira de três leguminosas arbóreas nativas do Nordeste do Brasil.
O objetivo deste trabalho foi estudar a produção e qualidade da serrapilheira de três leguminosas arbóreas nativas do Nordeste do Brasil, a faveira (Parkia platycephala Benth.), o pau-ferro (Caesalpinea ferrea Mart. ex Tul.) e o bordão-de-velho (Samanea saman (Jack.) Merr.) visando a inserção destas em sistemas silvipastoris..
Ciclagem de nutrientes por plantas de cobertura no cerrado.
O objetivo deste trabalho foi avaliar o desempenho de plantas cultivadas quanto ao acúmulo e a liberação de nutrientes, durante o período de entressafra, em um Latossolo Vermelho distroférrico de Santo Antônio de Goiás, GO e Rio Verde, GO. O delineamento experimental foi o de blocos casualizados, em esquema de parcelas subdivididas no tempo, com as plantas de cobertura avaliadas nas parcelas, e nas subparcelas, as épocas de coleta de fitomassa, com quatro repetições
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