Using quantum state protection via dissipation in a quantum-dot molecule to solve the Deutsch problem

The wide set of control parameters and reduced size scale make semiconductor quantum dots attractive candidates to implement solid-state quantum computation. Considering an asymmetric double quantum dot coupled by tunneling, we combine the action of a laser field and the spontaneous emission of the excitonic state to protect an arbitrary superposition state of the indirect exciton and ground state. As a by-product we show how to use the protected state to solve the Deutsch problem.Comment: 8 pages, 1 figure, 2 table

Produção sazonal do óleo de Copaifera reticulata Ducke na Floresta Nacional do Tapajós-PA.

A copaíba (Copaifera spp.) é uma espécie com potencial econômico para uso não madeireiro na região amazônica. Seu principal produto é o chamado óleo de copaíba, um óleo resina utilizado in natura na medicina popular e vendido em farmácias de manipulação, no tratamento de gripes e bronquites, como cicatrizante, diurético, antiinflamatório e antibiótico natural, ou após manipulação química, em cosméticos, tintas e vernizes, e fixador de odor em fragrâncias. No sistema de produção extrativista tradicional, a produção é muito variável. Assim, o objetivo deste trabalho foi avaliar a produção do óleo de copaíba da espécie Copaifera reticulata Ducke, em duas estações climáticas distintas na Floresta Nacional do Tapajós - PA. As amostras do óleo -resina de C. reticulata foram coletadas no quilômetro 67 da Floresta Nacional do Tapajós (FLONA), em Belterra - PA. As árvores foram perfuradas com um trado tradicional de 2 cm de diâmetro e 45 cm de comprimento, fazendo-se do dois orifícios nas alturas de 1 m e 1,50 m, respectivamente. As amostras foram armazenadas em recipientes plásticos previamente identificados e protegidos pela ação da luz por meio de papel aluminizado. O período de coleta foi de fevereiro de 2008 a fevereiro de 2009, num intervalo de quatro meses, perfazendo um total de quatro coletas. Os resultados indicaram que no mês de outubro de 2008 ocorreu a maior produção de óleo de copaíba na área coletada, coincidindo com o período menos chuvoso e no mês de fevereiro de 2009 foram obtidos os menores volumes de óleo, coincidindo com o período de maior precipitação pluviométrico

Scattering and Bound State Green's Functions on a Plane via so(2,1) Lie Algebra

We calculate the Green's functions for the particle-vortex system, for two anyons on a plane with and without a harmonic regulator and in a uniform magnetic field. These Green's functions which describe scattering or bound states (depending on the specific potential in each case) are obtained exactly using an algebraic method related to the SO(2,1) Lie group. From these Green's functions we obtain the corresponding wave functions and for the bound states we also find the energy spectra.Comment: 21 Latex pages. Typos corrected. Results unchanged. Version to appear in JM

Compression and bending behavior of steel fiber reinforced self-compacting concrete

A method to design cost competitive steel fiber reinforced self-compacting concrete (SFRSCC) for precasting industrial applications is described in this paper. Since demolding the elements as soon as possible is an important requirement in this industry, the influence of the age on the resistance and toughness of the designed SFRSCC was assessed carrying out an experimental program. Based on the force-deflection relationship obtained in the three point bending notched beam tests performed according to the RILEM TC 162-TDF recommendations, the stress-crack opening relationship of the SFRSCC was determined. The influence of the SFRSCC age on the fracture parameters of this material was analyzed.Inserido no programa de pesquisa suportado pelo FEDER e o Ministério da Ciência e Tecnologia (MCT) e promovido pelo Agencia de Inovação (ADI)

New sol-gel-derived magnetic bioactive glass-ceramics containing superparamagnetic hematite nanocrystals for hyperthermia application

Although the three main phases of iron oxide – hematite, maghemite, and magnetite – exhibit superparamagnetic properties at the nanoscale, only maghemite and magnetite phases have been explored in magnetic bioactive glass-ceramics aimed at applications in cancer treatment by hyperthermia. In this work, it is reported for the first time the superparamagnetic properties of hematite nanocrystals grown in a 58S bioactive glass matrix derived from sol-gel synthesis. The glass-ceramics are based on the (100-x)(58SiO2-33CaO-9P2O5)-xFe2O3 system (x = 10, 20 and 30 wt%). A thermal treatment leads to the growth of hematite (α-Fe2O3) nanocrystals, conferring superparamagnetic properties to the glass-ceramics, which is enough to produce heat under an external alternating magnetic field. Besides, the crystallization does not inhibit materials bioactivity, evidenced by the formation of calcium phosphate onto the glass-ceramic surface upon soaking in simulated body fluid. Moreover, their cytotoxicity is similar to other magnetic bioactive glass-ceramics reported in the literature. Finally, these results suggest that hematite nanocrystals' superparamagnetic properties may be explored in multifunctional glass-ceramics applied in bone cancer treatment by hyperthermia allied to bone regeneration