7,142 research outputs found

    Turning catalytically active pores into active pumps

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    We develop a semi-analytical model of self-diffusioosmotic transport in active pores, which includes advective transport and the inverse chemical reaction which consumes solute. In previous work (Phys. Rev. Lett. 129, 188003, 2022), we have demonstrated the existence of a spontaneous symmetry breaking in fore-aft symmetric pores that enables them to function as a micropump. We now show that this pumping transition is controlled by three timescales. Two timescales characterize advective and diffusive transport. The third timescale corresponds to how long a solute molecule resides in the pore before being consumed. Introducing asymmetry to the pore (either via the shape or the catalytic coating) reveals a second type of advection-enabled transitions. In asymmetric pores, the flow rate exhibits discontinuous jumps and hysteresis loops upon tuning the parameters that control the asymmetry. This work demonstrates the interconnected roles of shape and catalytic patterning in the dynamics of active pores, and shows how to design a pump for optimum performance

    Efeito da restrição hdrico sobre a germinação de Mimosa verrucosa Benth. (Leguminosae - Mimosaceae).

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    Suplemento. Edição dos Resumos do XIII Congresso Brasileiro de Fisiologia Vegetal; XIV Reunião Latino-Americana de Fisiologia Vegetal, Búzios, set. 2011

    Multi-band Superconductivity in the Chevrel Phases SnMo6S8 and PbMo6S8

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    Sub-Kelvin scanning tunnelling spectroscopy in the Chevrel Phases SnMo6S8 and PbMo6S8 reveals two distinct superconducting gaps with Delta_1 = 3 meV, Delta_2 ~ 1.0 meV and Delta_1 = 3.1 meV, Delta_2 ~ 1.4 meV respectively. The gap distribution is strongly anisotropic, with Delta_2 predominantly seen when scanning across unit-cell steps on the (001) sample surface. The spectra are well-fitted by an anisotropic two-band BCS s-wave gap function. Our spectroscopic data are confirmed by electronic heat capacity measurements which also provide evidence for a twin-gap scenario.Comment: 5 pages, 4 figure

    Gerador de relatórios Purus.

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    Arquitetura do Purus. Arquivo de definição de dados (DataSource). Arquivo de definição de relatório. Recursos. Agrupamento. Funções do grupo. Parametrização de definição de relatório. Inclusão de caracteres ASCII. Formatação de dados. Relatórios no formato CSV. Execução do Purus. Reportmanager.bitstream/CNPTIA/9889/1/comuntec30.pdfAcesso em: 30 maio 2008

    Dynamics of defect formation

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    A dynamic symmetry-breaking transition with noise and inertia is analyzed. Exact solution of the linearized equation that describes the critical region allows precise calculation (exponent and prefactor) of the number of defects produced as a function of the rate of increase of the critical parameter. The procedure is valid in both the overdamped and underdamped limits. In one space dimension, we perform quantitative comparison with numerical simulations of the nonlinear nonautonomous stochastic partial differential equation and report on signatures of underdamped dynamics.Comment: 4 pages, LaTeX, 4 figures. Submitted to Physical Revie

    Avaliações da subtração dos elementos N, P e K sobre a produção e qualidade de frutos de amoreira-preta.

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