Avaliação de hibridos triplóides de melancia no Vale do Sub-médio São Francisco.

O desempenho agronômico de doze híbridos de melancia sem sementes foi avaliado no município de Petrolina -PE. Foram utilizados os híbridos Tiffany (Asgrow), Nova, AF-180, AF-179, AF-178, AF-177, AF-176 (Sakata-Agroflora), W-691 (Sainoda), Ailet 1, Ailet 2, HLT- 02 e H L T -03 (Embrapa Semi-Árido). O experimento foi realizado no delineamento de blocos ao acaso com três repetições de dez plantas e espaçamento de 3,0 x 1,0 m. Foram avaliados o número de dias para o aparecimento da primeira flor feminina, número de frutos por planta, peso médio de frutos, teor de sólidos solúveis, espessura média da casca, percentual de frutos com sementes e percentual de frutos com ocamento. Todos os híbridos apresentaram produtividade e teor de sólidos solúveis em níveis satisfatórios, no entanto verificou-se elevada ocorrência de frutos com sementes verdadeiras e com problemas de ocamento na polpa. Os altos coeficientes de variação observados na análise de algumas variáveis sugerem a necessidade de realizar novos ensaios, utilizando-se parcelas maiores, a fim de aumentar a precisão do experimento.Suplemento 2. Edição do 42 Congresso Brasileiro de Olericultura; 11 Congresso Latino Americano de Horticultura, Uberlândia, jul. 2002

Diluted antiferromagnet in a ferromagnetic enviroment

The question of robustness of a network under random ``attacks'' is treated in the framework of critical phenomena. The persistence of spontaneous magnetization of a ferromagnetic system to the random inclusion of antiferromagnetic interactions is investigated. After examing the static properties of the quenched version (in respect to the random antiferromagnetic interactions) of the model, the persistence of the magnetization is analysed also in the annealed approximation, and the difference in the results are discussed

Decoherence of tripartite states - a trapped ion coupled to an optical cavity

We investigate the non-dissipative decoherence of three qubit system obtained by manipulating the state of a trapped two-level ion coupled to an optical cavity. Modelling the environment as a set of noninteracting harmonic oscillators, analytical expressions for the state operator of tripartite composite system, the probability of generating maximally entangled GHZ state, and the population inversion have been obtained. The pointer observable is the energy of the isolated quantum system. Coupling to environment results in exponential decay of off diagonal matrix elements of the state operator with time as well as a phase decoherence of the component states. Numerical calculations to examine the time evolution of GHZ state generation probability and population inversion for different system environment coupling strengths are performed. Using negativity as an entanglement measure and linear entropy as a measure of mixedness, the entanglement dynamics of the tripartite system in the presence of decoherence is analysed.Comment: Revised version, errors corrected and references added. 12 pages, 6 figures, Presented at ICSSUR May 2005, Besancon, Franc

The balance between sustainability dimensions: ecological base familiar smallholders' case from Coagrosol/Brazil .

This report shows some initial results about the research project entitled GlobalOrg, on a Brazilian case study, investigating the sustainability of tropical fruit organic farming in a global food chains perspective. It was performed an analysis about the production strategies of certified units of a familiar smalholders cooperative from Itápolis-SP-Brazil. In this analysis it was verified the application of sustainability principles recommended by the ecological based agriculture, focused on the agrobiodiversity, material recycling and the social-economic aspects from the agroecology conversion process. The research occurs through the complementarities provided by a combination of sociological and agronomic research methods, it means, qualitative interviews and questionnaire application with semi-structured questions. What was concluded is that the establishment of an economic relationship between the cooperative and a fair-trade international entity stimulates an interesting growing in the production diversity and also stimulates the application of different principles of ecological based agriculture. It indicates an important balance between the sustainability dimensions and demonstrates a visible attitude change in the natural resource exploration in this region

Spin-glass behaviour on random lattices

The ground-state phase diagram of an Ising spin-glass model on a random graph with an arbitrary fraction $w$ of ferromagnetic interactions is analysed in the presence of an external field. Using the replica method, and performing an analysis of stability of the replica-symmetric solution, it is shown that $w=1/2$, correponding to an unbiased spin glass, is a singular point in the phase diagram, separating a region with a spin-glass phase ($w<1/2$) from a region with spin-glass, ferromagnetic, mixed, and paramagnetic phases ($w>1/2$)

Micromorfologia aplicada a morfometria de agregados.

A morfometria geralmente é utilizada para análise grãos em pedologia, no entanto este trabalho teve como objetivo utilizar a técnica da micromorfologia para estudo de morfometria de agregados dos solos para que possa servir como subsídio a caracterização da estrutura do solo em escala micro. Foi realizada análise de 8 lâminas correspondente a diferentes classes de solos. Foram calculadas a porosidade e atributos morfométricos, como: área, perímetro, arredondamento, maior eixo e menor eixo utilizando o software Quantiporo. Com auxílio do Microsoft® Office Excel complementou-se os atributos alongamento e compacidade dos agregados. Em geral, os resultados de porosidade concordam com classe textural e estrutura de cada perfil, encontrando-se maior porosidade em solos mais argilosos e siltosos do que nos arenosos; isso devido a quantidade de microporos nesses solos. Encontraram-se maiores semelhanças dos atributos de solos nas classes de tamanho de agregados do que em relação as diferentes classes de solos. Mesmo sendo analisada uma parte muito pequena de solo para representar uma classe de solo, os resultados mostraram coerência, visto que, houve uma similaridade entre os perfis de mesma classe e também aqueles representando uma mesma profundidade (0-10 cm)

Characterization of the Intra-Unit-Cell magnetic order in Bi2Sr2CaCu2O8+d

As in YBa2Cu3O6+x and HgBa2CuO8+d, the pseudo-gap state in Bi2Sr2CaCu2O8+d is characterized by the existence of an intra-unit-cell magnetic order revealed by polarized neutron scattering technique. We report here a supplementary set of polarized neutron scattering measurements for which the direction of the magnetic moment is determined and the magnetic intensity is calibrated in absolute units. The new data allow a close comparison between bilayer systems YBa2Cu3O6+x and Bi2Sr2CaCu2O8+d and rise important questions concerning the range of the magnetic correlations and the role of disorder around optimal doping.Comment: 12 pages, 8 figures, submitted to physical review