Browsing by Author "Porta, Micaela"

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    Origin of magnetic and magnetoelastic tweedlike precursor modulations in ferroic materials
    Saxena, A.; Castan, T.; Planes, A.; Porta, Micaela; Kishi, Y.; Lograsso, Thomas A.; Viehland, Dwight D.; Wuttig, Manfred; De Graef, M. (American Physical Society, 2004-05-14)
    Based on experimental observations of modulated magnetic patterns in a Co(0.5)Ni(0.205)Ga(0.295) alloy, we propose a model to describe a ( purely) magnetic tweed and a magnetoelastic tweed. The former arises above the Curie (or Neel) temperature due to magnetic disorder. The latter results from compositional fluctuations coupling to strain and then to magnetism through the magnetoelastic interaction above the structural transition temperature. We discuss the origin of purely magnetic and magnetoelastic precursor modulations and their experimental thermodynamic signatures.
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    Trunk Flexion Monitoring among Warehouse Workers Using a Single Inertial Sensor and the Influence of Different Sampling Durations
    Porta, Micaela; Pau, Massimiliano; Orrù, Pier Francesco; Nussbaum, Maury A. (MDPI, 2020-09-28)
    Trunk flexion represents a risk factor for the onset of low-back disorders, yet limited quantitative data exist regarding flexion exposures in actual working conditions. In this study, we evaluated the potential of using a single inertial measurement unit (IMU) to classify trunk flexion, in terms of amplitude, frequency, and duration, and assessed the influence of alternative time durations on exposure results. Twelve warehouse workers were monitored during two hours of an actual shift while wearing a single IMU on their low back. Trunk flexion data were reduced using exposure variation analysis integrated with recommended exposure thresholds. Workers spent 5.1% of their working time with trunk flexion of 30–60° and 2.3% with flexion of 60–90°. Depending on the level of acceptable error, relatively shorter monitoring periods (up to 50 min) might be sufficient to characterize trunk flexion exposures. Future work is needed, however, to determine if these results generalize to other postural exposures and tasks.