536 research outputs found

    Genetic variability of meat quality traits in Chianina beef cattle

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    The heritability of quality traits (chemical composition, colour, tenderness and water-holding capacity) of the meat derivingfrom three muscles (Triceps brachii, Longissimus dorsi and Semitendinosus) was evaluated in 92 young Chianinabulls. The animals were raised on two farms with different feeding programs, and were slaughtered at approximately 19months of age. Single pair correlations were considered in order to evidence the relationships between the same traitsdetected in the three muscles and between all the traits of the same muscle.The h2 values range from 0.00 to 0.24 for the chemical composition, from 0.00 to 0.19 for colour parameters, from 0.03to 0.31 for those observed after 48 h, and from 0.00 to 0.08 for tenderness and water-holding capacity. The values werenot homogeneous for the three muscles. The most heritable trait was yellowness (b*48) in all three muscles, with valuesof 0.11 in the Longissimus dorsi, 0.23 in the Semitendinosus, and 0.31 in the Triceps brachii. Conversely, tendernessappeared to have a low heritability, as did the parameters relating to the water-holding capacity. Colour traitsobserved before and after 48 h of storage generally were significantly and positively correlated, indicating that certaincolour characteristics are maintained even after 48 h of storage. There was not always a close relationship between thetraits of each muscles: significant correlations existed between the Triceps brachii and the Longissimus dorsi muscles,confirming the similar quality traits of their meat, while there were considerable differences between these muscles andthe Semitendinosus

    Refined Rigid Block Model for In-Plane Loaded Masonry

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    In this work, a refined rigid block model is proposed for studying the in-plane behavior of regular masonry. The rigid block model is based on an existing discrete/rigid model with rigid blocks and elastoplastic interfaces that already proven its effectiveness in representing masonry behavior in linear and nonlinear fields. In this case, the proposed model is improved by assuming rigid quadrilateral elements connected by one-dimensional nonlinear interfaces, which are adopted both to represent mortar (or dry) joints between the blocks and also to represent inner potential cracks into the blocks. Furthermore, the softening behavior of interfaces in tension and shear is taken into account. Several numerical tests are performed by considering masonry panels with regular texture subjected to compression and shear. Particular attention is given to the collapse mechanisms and the pushover curves obtained numerically and compared with existing numerical and laboratory results. Furthermore, the numerical tests aim to evaluate the applicability limits of the proposed model with respect to existing results

    Refined Rigid Block Model for In-Plane Loaded Masonry

    Get PDF
    In this work, a refined rigid block model is proposed for studying the in-plane behavior of regular masonry. The rigid block model is based on an existing discrete/rigid model with rigid blocks and elastoplastic interfaces that already proven its effectiveness in representing masonry behavior in linear and nonlinear fields. In this case, the proposed model is improved by assuming rigid quadrilateral elements connected by one-dimensional nonlinear interfaces, which are adopted both to represent mortar (or dry) joints between the blocks and also to represent inner potential cracks into the blocks. Furthermore, the softening behavior of interfaces in tension and shear is taken into account. Several numerical tests are performed by considering masonry panels with regular texture subjected to compression and shear. Particular attention is given to the collapse mechanisms and the pushover curves obtained numerically and compared with existing numerical and laboratory results. Furthermore, the numerical tests aim to evaluate the applicability limits of the proposed model with respect to existing results

    Subtle differences in growth rate drive contrasting responses of ephemeral primary producers to recurrent disturbances

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    Although the importance of time after disturbance is well established in the ecological literature, studies examining how differences in growth rate affect species recovery and persistence in relation to the interval between recurrent perturbations are rare. We examined the response of two ephemeral primary producers inhabiting high-shore rock pools, epilithic microphytobenthos (EMPB), and green filamentous algae, to disturbance regimes varying for the time interval between consecutive events. Informed from an empirically parametrized growth model's outcomes, we tested the hypothesis that EMPB would be able to recover from more frequent disturbance compared with filamentous algae in a field experiment involving three physical disturbance patterns differing for the clustering degree: high, moderate, and low (20, 40, and 80 days between disturbances). We predicted that: high clustering would prevent the recovery of both taxa; moderate clustering would prevent the recovery of the slower growing taxon only (filamentous algae); both taxa would recover under low clustering. Results showed that EMPB persisted independently of the clustering degree, whereas filamentous algae did not withstand any disturbance regime. Dramatically different effects of disturbance on organisms with subtle differences in their growth rate indicate that even stronger responses may be expected from taxa with more markedly contrasting life histories

    Effect of Substrates and Thermal Treatments on Metalorganic Chemical Vapor Deposition-Grown Sb2Te3 Thin Films

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    Antimony telluride (Sb2Te3) thin films were obtained by metalorganic chemical vapor deposition (MOCVD). The films were grown on crystalline Si(100) and Al2O3(0001) and amorphous SiO2 and alpha-Al2O3 substrates. Their structural properties were compared with those of the Sb2Te3/Si(111) heterostructure. In addition to the effect of the substrate, the influence of pre- and post-growth thermal annealing is also presented. The quality of the films is discussed by comparing their morphological properties, such as roughness and granularity, and ascertaining their crystallinity and their in-plane and out-of-plane orientation
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