End-Of-Use Fly Ash as an Effective Reinforcing Filler in Green Polymer Composites.

The aim of this study is to use fly ash powder in an environmentally friendly matrix, in a novel way, addressing environmental and disposal problems. Fly ash/epoxy composites were prepared and studied varying the filler content. An investigation of structural and morphological characteristics was conducted using of X-ray diffraction patterns and scanning electron microscopy images, which revealed the successful fabrication of composites. Thermomechanical properties were studied via dynamic mechanical analysis and static mechanical tests. The composites exhibited an improved mechanical response. Broadband dielectric spectroscopy was used to investigate the dielectric response of the composite systems over the frequency range from 10-1 to 107 Hz and the temperature range from 30 to 160 °C. The analysis revealed the presence of three relaxation processes in the spectra of the tested systems. Interfacial polarization, the glass-to-rubber transition of the polymer matrix, and the rearrangement of polar side groups along the polymer chain are the processes that occur under a descending relaxation time. It was found that dielectric permittivity increases with filler content. Finally, the influence of filler content and the applied voltage under dc conditions was analyzed to determine the ability of the composites to store and retrieve electric energy. Fly ash improved the efficiency of the storing/retrieving energy of the composites.

Numerical simulation data of building integrated solar thermal collectors under diverse conditions.

This dataset presents the thermal performance of building-integrated flat solar collectors with a uniform and multiple riser structure. The input data of the numerical model were obtained with the use of the PVGIS tool. Solar radiation and ambient temperature values at slopes 0°, 45°, and 90° were extracted and used as boundary conditions. Numerical calculations were carried using Finite Element (FE) analysis. Three-dimensional transient models were developed to calculate the investigated configurations' thermal performance based on the environmental temperature, the solar radiation, and the inclination angle. The numerical model was validated with the use of an experimental data set showing a good agreement between the two models with RMSE of 5%. Data of hourly heat flux through the building masonry with the building-integrated solar collector and the average fluid temperature of each system is presented.