Filters

2016 - 201912020 - 20212

More filters

20223
Reset filters

Settings

Publisher: Bristol : IOP Publ. × Subject: Specific heat ×

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Magnetocaloric properties of multicomponent Laves phase compounds and their composites
    (Bristol : IOP Publ., 2021) Ćwik, J.; Koshkid’ko, Yu; Nenkov, K.; Kolchugina, N.
    Heat capacity measurements have been performed for multicomponent (Ho0.9Er0.1)1-xGdxCo2 compounds with x = 0.05, 0.1, and 0.15. The isothermal magnetic entropy change, ΔSmag, allowing the estimation of the magnetocaloric effect, was determined based on the heat capacity measurements in magnetic fields up to 2 T. A numerical method, with the magnetic entropy change of individual (Ho0.9Er0.1)1-xGdxCo2 compounds, was used to calculate the optimal molar composition of the constituents and the resulting change of the isothermal magnetic entropy of composite, ΔScomp. The results show that proposed composite can be considered as a refrigerant material in magnetic refrigerators performing an Ericsson cycle in a temperature range of 90-130 K.
  • Thumbnail Image
    Item
    Some remarks on a model for rate-independent damage in thermo-visco-elastodynamics
    (Bristol : IOP Publ., 2016) Lazzaroni, Giuliano; Rossi, Riccarda; Thomas, Marita; Toader, Rodica
    This note deals with the analysis of a model for partial damage, where the rate- independent, unidirectional flow rule for the damage variable is coupled with the rate-dependent heat equation, and with the momentum balance featuring inertia and viscosity according to Kelvin-Voigt rheology. The results presented here combine the approach from Roubicek [1, 2] with the methods from Lazzaroni/Rossi/Thomas/Toader [3]. The present analysis encompasses, differently from [2], the monotonicity in time of damage and the dependence of the viscous tensor on damage and temperature, and, unlike [3], a nonconstant heat capacity and a time-dependent Dirichlet loading.
  • Thumbnail Image
    Item
    Shielding Effect on Flux Trapping in Pulsed-Field Magnetizing for Mg-B Bulk Magnet
    (Bristol : IOP Publ., 2021) Oka, T.; Yamanaka, K.; Sudo, K.; Dadiel, L.; Ogawa, J.; Yokoyama, K.; Häßler, W.; Noudem, J.; Berger, K.; Sakai, N.; Miryala, M.; Murakami, M.
    MgB2 superconducting bulk materials are characterized as simple and uniform metallic compounds, and capable of trapping field of non-distorted conical shapes. Although pulsed-field magnetization technique (PFM) is expected to be a cheap and an easy way to activate them, the heat generation due to the magnetic flux motion causes serious degradation of captured fields. The authors precisely estimated the flux trapping property of the bulk samples, found that the flux-shielding effect closely attributed to the sample dimensions. The magnetic field capturing of Ti-5.0wt% sample reached the highest value of 0.76 T. The applied field which reached the centre of the sample surface shifted from 1.0 T to 1.2 T with increasing sample thickness from 3.67 mm to 5.80 mm. This means that the shielding effect was enhanced with increasing the sample thickness. Moreover, Ti-addition affected the frequency of flux jump happenings. The occurrence of flux jumps was suppressed in 5.0wt%Ti-added sample. This means that the heat capacity of the compounds was promoted by Ti addition.