Optimization of plastic waste integration in cement bricks

Abstract Implementing plastic waste in construction materials is a sustainable disposal method to overcome plastic pollution. The current study aims to optimize the integration of plastic waste in cement bricks regarding their thermomechanical properties in order to develop an eco-friendly building material. Polyethylene terephthalate (PET) and high-density polyethylene (HDPE) partially substituted cement with different ratios (0, 2.5, 5, 7.5, 10, 20%). The type that achieved better thermomechanical performance further replaced the other brick components; sand and coarse aggregates to determine the optimum replacement scenario and best design mix. Laboratory experiments have been carried out to measure the compressive strength, indirect tensile strength, bulk density, and thermal conductivity of the new composites. The measured results revealed better performance for the samples with HDPE than PET. A boost in the compressive strength and indirect tensile strength was noticed for the samples obtaining a limited amount (up to 7.5%) of HDPE. However, a reduction in the tested mechanical properties occurs with higher substitution levels. With respect to thermal conductivity and bulk density, they decreased with the increase of plastic waste. The best mechanical behavior and the highest thermal resistance were obtained by partial replacement of coarse aggregates with 7.5% and 20% HDPE respectively. The results represent a good contribution to energy conservation, waste management and sustainability

Nanoreinforced Cast Al-Si Alloys with Al2O3, TiO2 and ZrO2 Nanoparticles

This study presents a new concept of refining and enhancing the properties of cast aluminum alloys by adding nanoparticles. In this work, the effect of adding alumina (Al2O3), titanium dioxide (TiO2) and zirconia (ZrO2) nano-particles (40 nm) to the aluminum cast alloy A356 as a base metal matrix was investigated. Alumina, titanium dioxide and zirconia nano-powders were stirred in the A356 matrix with different fraction ratios ranging from (0%–5%) by weight at variable stirring speeds ranging from (270, 800, 1500, 2150 rpm) in both the semisolid (600 °C) and liquid (700 °C) state using a constant stirring time of one minute. The cast microstructure exhibited change of grains from dendritic to spherical shape with increasing stirring speed. The fracture surface showed the presence of nanoparticles at the interdendritic spacing of the fracture surface and was confirmed with EDX analysis of these particles. The results of the study showed that the mechanical properties (strength, elongation and hardness) for the nanoreinforced castings using Al2O3, TiO2 and ZrO2 were enhanced for the castings made in the semi-solid state (600 °C) with 2 weight% Al2O3 and 3 weight% TiO2 or ZrO2 at 1500 rpm stirring speed

Optical Properties and Microstructure of TiNxOy and TiN Thin Films before and after Annealing at Different Conditions

TiN and TiNxOy thin films share many properties such as electrical and optical properties. In this work, a comparison is conducted between TiN (with and without annealing at 400 °C in air and vacuum) and TiNxOy thin films deposited by using RF magnetron sputtering with the same pure titanium target, Argon (Ar) flow rate, nitrogen flow rates, and deposition time on stainless steel substrates. In the case of TiNxOy thin film, oxygen was pumped in addition. The optical properties of the thin films were characterized by spectrophotometer, and Fourier transform infrared spectroscopy (FTIR). The morphology, topography, and structure were studied by scanning electron microscope (SEM), atomic force microscope (AFM), and X-ray diffraction (XRD). The results show that both thin films have metal-like behavior with some similarities in phases, structure, and microstructure and differences in optical absorbance. It is shown that the absorbance of TiN (after vacuum-annealing) and TiNxOy have close absorbance percentages at the visible range of light with an unstable profile, while after air-annealing the optical absorbance of TiN exceeds that of TiNxOy. This work introduces annealed TiN thin films as a candidate solar selective absorber at high-temperature applications alternatively to TiNxOy

Solar PV Panels-Self-Cleaning Coating Material for Egyptian Climatic Conditions

The electrical efficiency of photovoltaic panels is affected by many environmental parameters, which have a negative impact on system electrical efficiency and cost of energy, dust and increased panel temperatures being the most serious in the MENA region. In this work, a few organic-based self-cleaning coatings are developed, and their effects on PVs’ electrical efficiency re assessed for polycrystalline panels exposed to natural soiling conditions outdoors at El-Sherouk City. The results show that monolithic hydrophobic-based coatings using paraffine and dimethyl-siloxane show up to 14.3% improvement in the electrical efficiency of the PV panels, but the role of nanoparticles TiO2 and Al2O3 addition needs further investigation. Hydrophobic-based coatings using dimethyl-siloxane reduce the coated panels’ surface temperature compared with the uncoated panel

Solar PV Panels-Self-Cleaning Coating Material for Egyptian Climatic Conditions

The electrical efficiency of photovoltaic panels is affected by many environmental parameters, which have a negative impact on system electrical efficiency and cost of energy, dust and increased panel temperatures being the most serious in the MENA region. In this work, a few organic-based self-cleaning coatings are developed, and their effects on PVs’ electrical efficiency re assessed for polycrystalline panels exposed to natural soiling conditions outdoors at El-Sherouk City. The results show that monolithic hydrophobic-based coatings using paraffine and dimethyl-siloxane show up to 14.3% improvement in the electrical efficiency of the PV panels, but the role of nanoparticles TiO2 and Al2O3 addition needs further investigation. Hydrophobic-based coatings using dimethyl-siloxane reduce the coated panels’ surface temperature compared with the uncoated panel