108,104 research outputs found

    Investigation of Micro Porosity Sintered wick in Vapor Chamber for Fan Less Design

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    Micro Porosity Sintered wick is made from metal injection molding processes, which provides a wick density with micro scale. It can keep more than 53 % working fluid inside the wick structure, and presents good pumping ability on working fluid transmission by fine infiltrated effect. Capillary pumping ability is the important factor in heat pipe design, and those general applications on wick structure are manufactured with groove type or screen type. Gravity affects capillary of these two types more than a sintered wick structure does, and mass heat transfer through vaporized working fluid determines the thermal performance of a vapor chamber. First of all, high density of porous wick supports high transmission ability of working fluid. The wick porosity is sintered in micro scale, which limits the bubble size while working fluid vaporizing on vapor section. Maximum heat transfer capacity increases dramatically as thermal resistance of wick decreases. This study on permeability design of wick structure is 0.5 - 0.7, especially permeability (R) = 0.5 can have the best performance, and its heat conductivity is 20 times to a heat pipe with diameter (Phi) = 10mm. Test data of this vapor chamber shows thermal performance increases over 33 %.Comment: Submitted on behalf of TIMA Editions (http://irevues.inist.fr/tima-editions

    Dibaryons with two heavy quarks

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    The relativistic six-quark equations are constructed in the framework of the dispersion relation technique. The relativistic six-quark amplitudes of dibaryons including the light uu, dd and heavy cc, bb quarks are calculated. The approximate solutions of these equations using the method based on the extraction of leading singularities of the heavy hexaquark amplitudes are obtained. The poles of these amplitudes determine the masses of charmed and bottom dibaryons with the isospins I=0, 1, 2 and the spin-parities JP=0+J^P=0^+, 1+1^+, 2+2^+.Comment: 10 pages, types corrected. arXiv admin note: substantial text overlap with arXiv:1105.081

    Heavy dibaryons

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    The relativistic six-quark equations are found in the framework of the dispersion relation technique. The approximate solutions of these equations using the method based on the extraction of leading singularities of the heavy hexaquark amplitudes are obtained. The relativistic six-quark amplitudes of dibaryons including the light quarks uu, dd and heavy quarks cc, bb are calculated. The poles of these amplitudes determine the masses of charmed and bottom dibaryons with the isospins 1/2, 3/2, 5/2.Comment: 16 page

    Weak antilocalization in a 2D electron gas with the chiral splitting of the spectrum

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    Motivated by the recent observation of the metal-insulator transition in Si-MOSFETs we consider the quantum interference correction to the conductivity in the presence of the Rashba spin splitting. For a small splitting, a crossover from the localizing to antilocalizing regime is obtained. The symplectic correction is revealed in the limit of a large separation between the chiral branches. The relevance of the chiral splitting for the 2D electron gas in Si-MOSFETs is discussed.Comment: 7 pages, REVTeX. Mistake corrected; in the limit of a large chiral splitting the correction to the conductivity does not vanish but approaches the symplectic valu
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