A comprehensive review on unleashing the power of hydrogen: revolutionizing energy systems for a sustainable future.

Population growth and environmental degradation are major concerns for sustainable development worldwide. Hydrogen is a clean and eco-friendly alternative to fossil fuels, with a heating value almost three times higher than other fossil fuels. It also has a clean production process, which helps to reduce the emission of hazardous pollutants and save the environment. Among the various production methodologies described in this review, biochemical production of hydrogen is considered more suitable as it uses waste organic matter instead of fossil fuels. This technology not only produces clean energy but also helps to manage waste more efficiently. However, the production of hydrogen obtained from this method is currently more expensive due to its early stage of development. Nevertheless, various research projects are underway to develop this method on a commercial scale.

Effect of size variation of fibre-shaped waste tyre rubber as fine aggregate on the ductility of self-compacting concrete.

Abandoning shredded waste tyre rubber (WTR) in cement-based mixes facilitates safe waste tyre disposal and conserves the natural resources used in construction materials. The engineering properties of such environment-friendly materials needed to be evaluated for field applications. This study examined integrating WTR fibre on microstructural, static load, and ductility properties of self-compacting concrete (SCC). The WTR fibre of 0.60-1.18-, 1.18-2.36-, and 2.36-4.75-mm sizes was used as fine aggregate at 10%, 20%, and 30% replacement levels. Microstructural characterisation of hardened concrete specimens was done by scanning electron microscopy. The compressive strength and static modulus of elasticity tests were used to examine static load resistance, while drop weight and rebound impact tests were used to investigate impact load resistance. The water permeability test was performed as a measure of the durability of SCC with WTR fibre. Relationships have been studied between dynamic MOE and impact tests and rebound and drop weight impact testing. The Weibull two-parameter distribution was used to analyse the drop weight test statically. The results show that WTR fibre size variations efficiently lowered the concrete stiffness reducing the brittleness. Furthermore, incorporating WTR fibre improved the impact resistance of SCC.

Environmental assessment, microstructural behaviour, stress-strain characteristics, and effect of exposure to extreme temperature on sustainable concrete made with dolomite mining residues.

Mining and extraction of stones and minerals play a significant role in many countries economic growth in the world. The production of dolomite minerals in various industries in India and other countries produces vast amounts of waste in different fractions. Disposal of these types of industrial wastes in an immense quantity causes environmental pollution. The performance of dolomite mining residues on concrete properties as a fine aggregate substitute was examined. The microstructural analysis was conducted on the concrete samples to find the effect of dolomite mining residues in concrete. The stress-strain behaviour of the dolomite mining residues concrete was studied. The effect of exposure to elevated temperature and freeze-thaw on concrete properties containing dolomite mining residues was found up to 100% at 10% incremental order. The thermogravimetric analysis (TGA) and differential thermogravimetry (DTG) tests were conducted on the dolomite mining residues and concrete samples. As a test result, concrete properties influence with the incorporation of the dolomite mining residues as a substitution of river sand, but no significant effect is observed in the concrete properties containing 10% dolomite mining residues. Up to 10% of dolomite production waste can be used as a sand substitute in concrete and other applications for sustainable development.

Effect of mechanically treated and untreated zinc tailing waste as cement substitute in concrete production: an experimental and statistical analysis.

Zinc tailing waste is a type of mine waste generated during the extraction of zinc metal. Disposal of a huge amount of mine tailing waste is an open area and tailing dam causing a negative impact on the natural ecosystem and human health. In this research study, the mechanical properties and durability performance of concrete containing zinc mine tailing waste was investigated through an experimental and statistical analysis. The mechanically treated and untreated zinc tailing waste was used as a cement substitute in concrete production. Concrete specimens were fabricated by replacing cement (0%, 5%, 10%, 15%, and 20%) with the mechanically treated and untreated zinc mine tailing waste. The effect of the zinc mine tailing waste was investigated by conducting the various mechanical (compressive strength and elastic modulus) tests, durability (ultrasonic pulse velocity, water absorption, chloride penetration, carbonation, sulfate attack) tests. The X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) on concrete samples were also conducted for microstructure analysis. According to the various tests conducted, all concrete properties showed comparable results at the 5% cement substitution in concrete by mechanically treated zinc tailing waste. However, the zinc tailing waste concrete was shown to be more sulphate resistance than the control concrete. Test findings suggest that it is feasible to use 10% mechanically treated and 5% untreated zinc tailing waste as a substitute for cement in concrete to reduce the adverse effect on the environment.