In recent times, composites made out of polymers and paraffin waxes were thought to be good thermal energy storage materials, in which the heat is stored as latent heat of fusion in the paraffin wax. In this study, phase change composite material with spherical shape calibrated based paraffin wax (RT27) was produced. The properties of the prepared composite phase change material have been characterized. The objective of this article was to study the energy storage and the energy recovery by using a phase change composite material. An experimental set-up consisting of fluxmetric measurement has been constructed to provide the thermal performance of the composite. In addition, a differential scanning calorimetry analysis was carried out. The experimental apparatus allows providing heat storage capacities and “apparent” thermal conductivities of the composite at the solid and liquid states, and also a measurement of the latent heat of fusion. The proposed test provides temperature and heat flux measurements at the material borders. The amount of energy exchanged during the variation of the thermodynamic state samples could be calculated when the boundary temperatures vary. In this article, one shows how it can allow the study of complex composite material with PCM. In particular, heat flux measurements make it possible to highlight very specific behaviors of these products and are thus a very interesting experimental source of data which comes to complete the traditional measurement methods like calorimetric device (differential scanning calorimetry).

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In recent years, considerable attention has been given to the development and utilization of natural fibres. This study examines the thermal properties of maize thermomechanical fibre reinforced high density polyethylene composites with competitive mechanical properties. The composites were produced by six different steps, namely: drying, cutting, mixing, compounding, pelletizing and injection moulding. Composite samples with fibre contents in the range 10–40 wt% were chosen to observe their effect on thermal and mechanical properties as the fibre content was increased. Measurements of thermophysical properties were obtained using periodic temperature ramp method. The material characterization was performed on a temperature range that extends from −20℃ to 120℃. It was found that the thermal conductivity and diffusivity of the composites decrease with fibre loading. The results showed that when the temperature is increased, a significant increase of both thermal effusivity and the factor [Formula: see text] was observed. A high-quality dispersion and adhesion of maize fibre in the high density polyethylene matrix was indicated by scanning electron microscopy. Good mechanical performance of the obtained composites was established considering the stress transfer at fibre–matrix interface.

The effects of monovalent alkali metal substitution into the lanthanide sites in oxides are presented. We report structural features, magnetic and electrical properties of these materials for . The lattice symmetry of the samples is found to be rhombohedral. All the phases are ferromagnetic, with Curie temperatures strongly dependent on x, reaching a maximum around 308 K for . A sharp drop of the resistivity is observed just below the Curie temperature. The ferromagnetic-metallic to paramagnetic-semiconducting transition is explained from the suggested distribution of the cations by the double exchange of pairs at the B-sublattice. Preliminary magnetoresistance measurements (MR) on bulk ceramic samples display an MR effect of the same amplitude as in the case of the alkaline earth substituted La manganites.