Photon pair-state preparation with tailored spectral properties by spontaneous four-wave mixing in photonic-crystal fiber

We study theoretically the generation of photon pairs by spontaneous four-wave mixing (SFWM) in photonic crystal optical fiber. We show that it is possible to engineer two-photon states with specific spectral correlation (``entanglement'') properties suitable for quantum information processing applications. We focus on the case exhibiting no spectral correlations in the two-photon component of the state, which we call factorability, and which allows heralding of single-photon pure-state wave packets without the need for spectral post filtering. We show that spontaneous four wave mixing exhibits a remarkable flexibility, permitting a wider class of two-photon states, including ultra-broadband, highly-anticorrelated states.Comment: 17 pages, 7 figures, submitte

Monitoramento das helmintoses gastrintestinais em rebanho leiteiro criado em sistema de produção orgânica na Fazendinha Agroecológica.

O objetivo oi utilizar técnicas parasitológicas para monitorar o grau de parasitismo como subsídio para a criação de programas de controle das infecções por nematóides gastrintestinais em vacas leiteiras criadas em sistema orgânico na Fazendinha Agroecológica, convênio Embrapa/ Universidade Federal Rural do Rio de Janeiro (UFRuralRJ)/ Pesagro-Rio.bitstream/item/39144/1/DOC261-09.pd

Squeezing generation and revivals in a cavity-ion system in contact with a reservoir

We consider a system consisting of a single two-level ion in a harmonic trap, which is localized inside a non-ideal optical cavity at zero temperature and subjected to the action of two external lasers. We are able to obtain an analytical solution for the total density operator of the system and show that squeezing in the motion of the ion and in the cavity field is generated. We also show that complete revivals of the states of the motion of the ion and of the cavity field occur periodically.Comment: 9 pages, 3 figure

Banco Ativo de Germoplasma de Arroz e Feijão: passado, presente e futuro.

O objetivo deste documento é apresentar um histórico do BAG Arroz e Feijão desde a sua criação até os dias atuais enfatizando as principais mudanças realizadas tanto em termos de infraestrutura como do manejo do germoplasma de arroz e feijão.bitstream/item/89928/1/seriedocumentos-288.pd

Sistemas silvipastoris: produção animal com benefícios ambientais.

Resumo: Sistemas silvipastoris constituem uma modalidade de sistema agroflorestal, que combinam forrageiras, árvores e animais, e que têm sido desenvolvidos em todas as regiões do país, com características específicas quanto às espécies utilizadas, ao arranjo temporal e espacial dos componentes e ao objetivo e funcionalidade do sistema, porém, ainda são pouco adotados. Este trabalho pretende apresentar demandas, demonstrar resultados de produção animal e perspectivas de fornecimento de serviços ambientais, mostrando o potencial de uso destes sistemas para diferentes regiões brasileiras, em especial, para o Nordeste. [Silvopastoral systems: animal production with environmental benefits]. Abstract: Silvopastoral systems are a form of agroforestry system that combine forages, trees and animals, which have been developed in all regions of Brazil, with specific characteristics as the species used, the temporal and spatial arrangement of components and the purpose and functionality of system, however, are still poorly adopted. This work intends to present demands, demonstrate results of animal production and prospects for providing environmental services, showing the potential use of these systems for different Brazilian regions, especially the Northeast

Sistemas silvipastoris: produção animal com benefícios ambientais.

Resumo: Sistemas silvipastoris constituem uma modalidade de sistema agroflorestal, que combinam forrageiras, árvores e animais, e que têm sido desenvolvidos em todas as regiões do país, com características específicas quanto às espécies utilizadas, ao arranjo temporal e espacial dos componentes e ao objetivo e funcionalidade do sistema, porém, ainda são pouco adotados. Este trabalho pretende apresentar demandas, demonstrar resultados de produção animal e perspectivas de fornecimento de serviços ambientais, mostrando o potencial de uso destes sistemas para diferentes regiões brasileiras, em especial, para o Nordeste. [Silvopastoral systems: animal production with environmental benefits]. Abstract: Silvopastoral systems are a form of agroforestry system that combine forages, trees and animals, which have been developed in all regions of Brazil, with specific characteristics as the species used, the temporal and spatial arrangement of components and the purpose and functionality of system, however, are still poorly adopted. This work intends to present demands, demonstrate results of animal production and prospects for providing environmental services, showing the potential use of these systems for different Brazilian regions, especially the Northeast

Viabilidade de sementes de feijão comum do Banco Ativo de Germoplasma da Embrapa Arroz e Feijão.

O Banco Ativo de Germoplasma (BAG) da Embrapa Arroz e Feijão possui 15.720 acessos de feijão, sendo a maioria deles acessos de feijão comum (Phaseolus vulgaris). Em 2009, foi iniciada uma reestruturação física, que incluía o inventário de todo acervo. O objetivo desse estudo foi avaliar a viabilidade de parte dos acessos de feijão comum do BAG.Pôster - graduação

Overdamped sine-Gordon kink in a thermal bath

We study the sine-Gordon kink diffusion at finite temperature in the overdamped limit. By means of a general perturbative approach, we calculate the first- and second-order (in temperature) contributions to the diffusion coefficient. We compare our analytical predictions with numerical simulations. The good agreement allows us to conclude that, up to temperatures where kink-antikink nucleation processes cannot be neglected, a diffusion constant linear and quadratic in temperature gives a very accurate description of the diffusive motion of the kink. The quadratic temperature dependence is shown to stem from the interaction with the phonons. In addition, we calculate and compute the average value $$ of the wave function as a function of time and show that its width grows with $\sqrt{t}$. We discuss the interpretation of this finding and show that it arises from the dispersion of the kink center positions of individual realizations which all keep their width.Comment: REVTeX, 12 pages, 10 figures, to appear in Phys Rev

Extended hydrodynamics from Enskog's equation for a two-dimensional system general formalism

Balance equations are derived from Enskog's kinetic equation for a two-dimensional system of hard disks using Grad's moment expansion method. This set of equations constitute an extended hydrodynamics for moderately dense bi-dimensional fluids. The set of independent hydrodynamic fields in the present formulations are: density, velocity, temperature {\em and also}--following Grad's original idea--the symmetric and traceless pressure tensor $p_{ij}$ and the heat flux vector $\mathbf q^{k}$. An approximation scheme similar in spirit to one made by Grad in his original work is made. Once the hydrodynamics is derived it is used to discuss the nature of a simple one-dimensional heat conduction problem. It is shown that, not too far from equilibrium, the nonequilibrium pressure in this case only depends on the density, temperature and heat flux vector.Comment: :9 pages, 1 figure, This will appear in J. Stat. Phys. with minor corrections and corresponds to Ref[9] of cond-mat/050710

Caracterização morfológica dos acessos de feijão comum (Phaseolus vulgaris).

A diversidade genética é a responsável por essa segurança e estabilidade de produção. A coleta, caracterização e manutenção desses acessos disponibilizará aos programas de melhoramento genes responsáveis por características desejáveis na obtenção de novas cultivares.Apresentação oral - graduação