609 research outputs found

    Translocation of natural microflora from muscle surface to interior by blade tenderization

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    The effect of blade tenderization on translocation of natural microflora from the surface to the interior of longissimus dorsi steaks aged for 7, 14, and 21 days was evaluated. Samples from the exterior and interior of steaks from blade-tenderized (BT) and non-blade-tenderized (N-BT) strip loins were analyzed for aerobic plate, coliform, and Escherichia coli counts. Results showed that BT translocated microorganisms (aerobic plate counts) from the exterior to the interior of muscle. Microorganism numbers increased with extended storage (P<.05). Counts of coliforms and Escherichia coli recovered from BT steaks were comparable to those from N-BT steaks because of very low exterior counts, showing the importance of good hygiene

    Crack path and fracture analysis in FSW of small diameter 6082-T6 aluminium tubes under tension-torsion loading

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    This paper reports part of the work done in a research project aimed at developing an optimised process to join 38. mm diameter tubes of 6082-T6 aluminium alloy using friction stir welding (FSW), and then to determine the fatigue performance under tension, torsion and tension-torsion loading conditions. The final outcome of the project is intended to be guidance for fatigue design of small diameter aluminium tubes joined by FSW, and this paper presents information on crack path and defects under the various loading conditions. Crack path analysis was performed using both low magnification stereo microscopy and scanning electron microscopy, in order to identify crack initiation sites, the direction of crack propagation and the interrelated influence of microstructure and weld geometry on the crack initiation path

    Multiaxial fatigue of aluminium friction stir welded joints: Preliminary results

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    The aim of the present research is to check the accuracy of the Modified Wöhler Curve Method (MWCM) in estimating the fatigue strength of friction stir (FS) welded tubular joints of Al 6082-T6 subjected to in-phase and out-of-phase multiaxial fatigue loading. The welded samples being investigated were manufactured by equipping an MTS I-STIR process development system with a retracting tool that was specifically designed and optimised for this purpose. These specimens were tested under proportional and non-proportional tension and torsion, the effect of non-zero mean stresses being also investigated. The validation exercise carried out by using the generated experimental results allowed us to prove that the MWCM (applied in terms of nominal stresses) is highly accurate in predicting the fatigue strength of the tested FS welded joints, its usage resulting in estimates falling with the uniaxial and torsional calibration scatter bands

    Fatigue behaviour of Al 6082-T6 friction stir welded tubular joints under torsional loading

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    The aim of the present research is to investigate the fatigue behaviour of friction stir (FS) welded tubular joints in aluminium alloy subjected to torsional fatigue loading. To manufacture the samples which were tested, an MTS I-STIR process development system was equipped with a retracting tool specifically designed for these tubular welds. Al 6082-T6 FS welded samples were tested under cyclic torsion with a nominal shear stress ratio equal to-1 and 0. The test data show that, strictly speaking, the presence of non-zero mean shear stresses has a detrimental effect on the overall torsional fatigue strength of the FS welded joints. However, the reanalysis discussed in the present paper suggests that, from a statistical point of view, any detrimental effect is small. This means that fatigue assessment under torsional fatigue loading of these FS welded tubular connections can be performed with little loss of accuracy by neglecting the presence of non-zero mean shear stresses

    Angular dependence of domain wall resistivity in SrRuO3_{{\bf 3}} films

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    SrRuO3{\rm SrRuO_3} is a 4d itinerant ferromagnet (Tc_{c} \sim 150 K) with stripe domain structure. Using high-quality thin films of SrRuO3_{3} we study the resistivity induced by its very narrow (3\sim 3 nm) Bloch domain walls, ρDW\rho_{DW} (DWR), at temperatures between 2 K and Tc_{c} as a function of the angle, θ\theta , between the electric current and the ferromagnetic domains walls. We find that ρDW(T,θ)=sin2θρDW(T,90)+B(θ)ρDW(T,0)\rho_{DW}(T,\theta)=\sin^2\theta \rho_{DW}(T,90)+B(\theta)\rho_{DW}(T,0) which provides the first experimental indication that the angular dependence of spin accumulation contribution to DWR is sin2θ\sin^2\theta. We expect magnetic multilayers to exhibit a similar behavior.Comment: 5 pages, 5 figure

    The Dipion Mass Spectrum In e+e- Annihilation and tau Decay: A Dynamical (rho0, omega, phi) Mixing Approach

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    We readdress the problem of finding a simultaneous description of the pion form factor data in e+e- annihilations and in tau decays. For this purpose, we work in the framework of the Hidden Local Symmetry (HLS) Lagrangian and modify the vector meson mass term by including the pion and kaon loop contributions. This leads us to define the physical rho, omega and phi fields as linear combinations of their ideal partners, with coefficients being meromorphic functions of s, the square of the 4--momentum flowing into the vector meson lines. This allows us to define a dynamical, i.e. s-dependent, vector meson mixing scheme. The model is overconstrained by extending the framework in order to include the description of all meson radiative (V P gamma and P gamma gamma couplings) and leptonic (Ve+e- couplings) decays and also the isospin breaking (omega/ phi --> pi+ pi-) decay modes. The model provides a simultaneous, consistent and good description of the e+e- and tau dipion spectra. The expression for pion form factor in the latter case is derived from those in the former case by switching off the isospin breaking effects specific to e+e- and switching on those for tau decays. Besides, the model also provides a good account of all decay modes of the form V P gamma, Pgamma gamma as well as the isospin breaking decay modes. It leads us to propose new reference values for the rho^0 --> e+ e- and omega --> pi+ pi- partial widths which are part of our description of the pion form factor. Other topics (phi --> K anti K, the rho meson mass and width parameters) are briefly discussed. Therefore, we confirm the 3.3 sigma discrepancy between the theoretical estimate of a_mu based on e+e- and its direct BNL measurement.Comment: 71 pages, 8 figures. Accepted by EPJ C. Version 3: correct minor typos, minor changes spread out into the text. Extension of Sections 12.2 and 12.3.5 and introduction of the new Appendix
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