Mustansiriyah Journal of Materials Engineering and Sustainability

The present investigation was performed to investigate the impact of untreated sewage water discharged from the new residential neighborhoods to the adjacent areas in the study area in “Al-Zafaraniya city” on the physicochemical properties of the soil. Samples were gathered at a 10-15 cm depth at various distances to determine Calcium, Magnesium and chloride, in addition to analyzing soil electrical conductivity, pH, total dissolved salts, and total hardness. The study results revealed that the concentration of calcium, magnesium and chloride elements increased significantly in soil samples close to the main source of pollution and affected by untreated sewage, compared to soil samples collected from another location (D) located 100 meters from the main source. It was also observed that the concentration of dissolved salts increased in the soil, coinciding with the increase in the concentration of these elements, which in turn was considered the reason for the increase in the total hardness and conductivity of this soil. This indicates that the soil near the main stream is polluted, as this pollution seriously affects human, plant and animal life in the area. The importance of the study lies in the need to find urgent solutions to reduce water pollution, whether for human use or for agriculture, by equipping a sewage treatment plant for the residential neighborhood in Zafaraniya and any similar city, directing the construction of sewage networks in residential neighborhoods to the nearest sewage treatment plant, and not discharging untreated water directly into the soil to ensure environmental safety.

The disposal of ceramic tiles from demolished buildings and olive stone waste has contributed to significant environmental challenges. Enhancing their reuse and recycling potential is crucial for sustainable solid waste management. This study investigates the viability of partially substituting fine aggregates in cement mortar using a mixture of olive stone (a natural waste) along with ceramic powder derived from wall tiles (an industrial waste). Thermal and mechanical properties were analyzed to assess performance. In addition to promoting environmentally friendly materials that improve buildings' energy efficiency, recycling construction debris helps reduce landfill accumulation. To assess the effect on material qualities, specimens of cement mortar were made using a 1:3 mix ratio and a 0.5 W/C ratio, with the addition of 5% to 25% of these waste materials. The inclusion of a superplasticizer improved workability and compressive strength. Various ratios were tested for thermal conductivity, flexural strength, density, as well as compressive strength. According to the results, the best performance was achieved when ceramic powder and olive stone accounted for 20% of the fine aggregate, increasing compressive strength by 54% as well as flexural strength by 67%, while thermal insulation improved by 25% at 28 days. This study validates the practicality of integrating olive along with ceramic waste to improve the insulating characteristics along with the mechanical characteristics of cement mortar.

To enhance the efficacy of thermal conversion systems, it is imperative to incorporate them with thermal energy storage mechanisms. Within the extensive selection of essential materials, phase change materials (PCMs) are identified as the top choice for the retention and later liberation of thermal energy, attributable to their notable latent heat of fusion. Generally, PCMs exhibit low thermal conductivity. Incorporating nano additives has been explored to improve the thermal characteristics of PCMs further. In our recent exploration, we augmented the thermal conductivity of paraffin wax using different mass concentration additions (1 wt. %, 3 wt. %, 5 wt. Titanium dioxide (TiO2) nanoparticles exist at a percentage that is roughly 10 nm in diameter. Researchers have noted that introducing TiO2 nanoparticles into the paraffin wax matrix affects the temperature at which phase changes occur. Also, the thermal conductivity in the resultant composites indicated a falling tendency as temperature increased, due to the increased surface interfacial thermal resistance between TiO2 nanoparticles and the wax matrix. A notable enhancement in thermal conductivity, quantified at approximately 10% and 7%, was recorded through the utilisation of spherical and trapezoidal capsules, respectively, at a nanoparticle loading of 5 wt. The atmospheric conditions are 50±5% humidity and the temp is at 15°C.

Experimental study is worked out on experimental system in which a concentric triple pipe heat exchanger made of copper consist the main part of it. The triple pipe heat exchanger consists of inner tube of 2 m length with inner and outer diameters of 1.27 cm and 1.5 cm respectively, the intermediate pipe of 1.5 m length with inner and outer diameters of 2.22 cm and 2.54 cm respectively and the outer pipe of 1m length with inner and diameters of 3.81 cm and 4.13 cm respectively. Nano-silicon dioxide (SiO2), nano-copper oxide (CuO) and nano-black iron oxide (Fe3O4) are used in different volume percent concentrations (0.1, 0.2, 0.3, 0.4 and 0.5) in water (base fluid), as a cooling (nano) fluid. The cooling (nano) fluid flows in different five-volume flow rates (100, 150, 200, 250 and 300 cm3/s) in inner and outer pipes countercurrently to hot water flowing at constant volume flow rate of 50 cm3/s in the middle pipe of the triple pipe heat exchanger. Experimentally, there were a dual advantageous effect on the heat transfer coefficient consequently on heat transfer rates achieved, one due to, the contact surface area between the cold and hot fluids offered by the triple pipe heat exchanger compared with double pipe of heat exchanger, and the second due to, adding the nanomaterials to cold fluid. These effects, led to increase in heat transfer rates and overall heat transfer coefficients. The increment in heat transfer rates reached to 24.2, 28.3 and 31.8% with using SiO2, CuO and Fe3O4 respectively. Whereas, the increment in combined overall heat transfer coefficients reached to 44.7, 53.9 and 62.2% with using SiO2, CuO and Fe3O4 respectively. Wherefore, the effectiveness, reached to 63, 65 and 67% with using SiO2, CuO and Fe3O4 respectively.

The purpose of thermal insulation is to reduce the rate of heat transfer. The goal of this work is to investigate the impact of various insulator species that can be utilized to increase thermal insulation. In the present investigation, natural heat transfer investigations are accomplished with a wooden box enclosure and four insulating materials with different thermal conductivity and two thicknesses of 2 cm and 4 cm for each piece. Four pieces of insulating material are PE foam, Polyisocyanurate, Polystyrene (XPS 300) and wood that is each piece attached in the middle space of the wooden test cell to achieve two parts up and down flow region. The experimental work is done with heat flux (350,500 and 650W/m2) and Ra numbers ranging from (2.19×105 to 1.30×106). Also, the wooden test cell is simulated using computational fluid dynamics by using 3D Fluent Ansys software program version 17.2 for temperature distribution through insulation and enclosure with heat flux (500 W/m2) and Ra numbers ranging from (2.19×105 to 1.30×106). The results are shown when there is a reduction in insulator conductivity, so a decrease in the heat transfer through the box walls results in preferable thermal insulation for the box. The relationship between thermal conductivity (k) and the optimum thickness of various insulation materials (topt) is investigated with a polynomial non-linear correlation. This correlation will be particularly useful in estimating the ideal thickness of insulators for minimizing heat transfer meanwhile an insulation material based solely on its thermal conductivity.