A study on fully developed turbulent convective heat transfer and pressure drop characteristics of Al2O3-Cu/water hybrid nanofluid flowing through a uniformly heated circular tube is presented in this paper. For this, Al2O3-Cu nanocomposite powder was synthesized in a thermo chemical route using hydrogen reduction technique and dispersed the hybrid nano powder in deionised water to form a stable hybrid nanofluid of 0.1% volume concentration. The prepared powder was characterized by X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) to confirm the chemical composition, determine the particle size and study the surface morphology. Stability of the nanofluid was ensured by pH and zeta potential measurements. The average heat transfer enhancement for Al2O3-Cu/water hybrid nanofluid is 8.02% when compared to pure water. The experimental results also showed that 0.1% Al2O3-Cu/water hybrid nanofluids have slightly higher friction factor compared to 0.1% Al2O3/water nanofluid. The empirical correlations proposed for Nusselt number and friction factor were well agreed with the experimental data.

Construction expenses have mostly grown unaffordable in recent years. Civil engineering institutes and stakeholders throughout the world have worked to develop recyclable and resource-saving concrete for building applications in order to reduce these expenses. The majority of environmental issues arise from the disposal of trash in areas where marble sculpting takes place. The marble stone slurry generates both stone slurry and solid wastes, and with the massive discharge of marble trash locally, emphasis has been focused on the utilisation of waste material. This study looked into the use of marble dust powder in concrete, with varied percentages of marble dust (0%, 5%, 10%, 15% & 20%) replaced by sharp sand in M20 grade concrete mixes, while the water cement ratio was kept constant at 0.45. The compressive and split tensile strength of the concrete were evaluated after 7 and 28 days of curing time to determine its quality, performance, and dependability. The laboratory findings revealed that replacing marble dust powder with cement boosted concrete strength by up to 10% in terms of compressive load resistance and tensile strength.

No abstract

No abstract