1,198 research outputs found

    Rate of Convergence to Barenblatt Profiles for the Fast Diffusion Equation

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    We study the asymptotic behaviour of positive solutions of the Cauchy problem for the fast diffusion equation near the extinction time. We find a continuum of rates of convergence to a self-similar profile. These rates depend explicitly on the spatial decay rates of initial data

    Experimental Estimation of Slipping in the Supporting Point of a Biped Robot

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    When developing a gait cycle on a low-friction surface, a biped robot eventually tends to slip. In general, it is commonto overcome this problem by means of either slow movements or physical adaptations of the robot at the contact pointwith the walking surface in order to increase the frictional characteristics. In the case of slipping, several types ofsensors have been used to identify the relative displacement at the contact point of the supporting leg with the walkingsurface for control purposes. This work is focused on the experimental implementation of a low-cost force sensor as ameasurement system of the slipping phenomenon. It is shown how, supported on a suitable change of coordinates,the force measurement at the contact point is used to obtain the total displacement at the supporting point due to thelow-friction conditions. This is an important issue when an accurate Cartesian task is required

    Somatic education approaches in piano studies: A snapshot of Spanish conservatoire practices

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    Somatic education in professional instrumental teaching is an emerging field in Spanish conservatoire culture. Although we find that the Alexander Technique was included in some European institutions since the middle of the XXth Century, this was not the case in the Spanish context. By means of a qualitative study, through document analysis and fifteen in-depth interviews with somatic teachers, the statutory frameworks of professional Piano studies and teaching plans related to somatic education in Spanish conservatoires, the principles that support them and the current practices that are undertaken in professional piano studies were analyzed. We found that there are eclectic approaches and practices in correlation with the background of the teachers in charge of the courses. Four main orientations can be described: somatic education per se; ergonomics and postural technique; body communication, training and technique; and mental and concentration control techniques. Further research to explore the interrelationships between somatic approaches and instrumental teaching would greatly benefit the fieldS

    Effect of high-pressure processing of Atlantic mackerel (Scomber scombrus) on biochemical changes during commercial frozen storage

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    This research focuses on biochemical changes related to quality losses observed in Atlantic mackerel (Scomber scombrus) muscle stored under commercial frozen storage conditions (9 months, −18 °C) when subjected to highhydrostatic pressure (HHP) treatments (125, 150, 175, and 200 MPa for 0 min) before freezing. After freezing, free fatty acid (FFA) formation (lipid hydrolysis assessment) showed a marked inhibition in HHP-treated fish and during frozen storage of samples treated at 175 MPa. Fluorescence ratio (FR) assessment of tertiary lipid oxidation showed a partial inhibitory effect during the 0–9-month period for samples treated at 175 and 200 MPa. After a 3-month storage of samples treated at these pressure levels, one-dimensional SDS-PAGE analysis of the sarcoplasmic protein fraction revealed the disappearance of a band; additionally, samples treated at 150 MPa showed the same effect at month 9. After gel excision, trypsin digestion, tandem mass spectrometry (MS/MS), and sequence database analysis, the band was identified as phosphoglycerate mutase 2 (28.7 kDa). On the other hand, HHP processing did not show a significant effect on trimethylamine (TMA) values, primary and secondary lipid oxidation, PUFA levels, 1-D myofibril protein pattern, and the activity of acid phosphatase and cathepsins B and D. Biochemical quality indices such as FFA, TMA, and FR and the activity of acid phosphatase and cathepsin B showed a progressive increase throughout the frozen storage of all samples
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