Synthesis of α-alumina developed from waste aluminium using precipitation technique

The heated aluminium containers were added to a solution of 8.0 M H2SO4 solution, which eventually yielded a solution of Al2(SO4)3 after a series of stepwise precipitation reactions. Al2(SO4)3 was presented in large quantities of H2SO4 in the white semi-fluid solution; there were some unreacted aluminium parts. The solution was subjected to filtration and then mixed with anion in a ratio of 2:3, this resulted in the formation of a white layer Al2(SO4)3•18H2O. Thereafter, Al2(SO4)3•18H2O was calcined in an electric oven for 2 h at various calcination temperatures (500, 700, 900, 1100, and 1300°C). The mixtures were heated and cooled at a rate of 10°C/min. XRD was employed to investigate variations in temperature and determination of elemental accumulation of alumina produced. Ah(SO4)3•18H2O was due to a series of aluminium compositions produced from dehydration. All transitions from low temperatures to aluminium phases were converted to high-temperature α-Al2O3. The results obtained from X-ray disintegration showed that the α-Al2O3 phase was obtained at a reaction temperature of about 1150°C and above

A Bibliometric Review of Research Trends on Kenaf Fiber Reinforced Concrete

To prevent the excessive depletion of natural resources, sustainable development requires using alternate sustainable materials. Researchers in the field of advanced construction materials are increasingly paying attention to kenaf fibers as a "green" material because of their possible application in composites to advance sustainable development. However, there has been no attempt of scientometric analysis to investigate the comprehensive understanding of the present state of applications of kenaf fibers in reinforced concrete. The study aims to perform a bibliometric analysis of the existing kenaf fibers reinforced concrete literature and to provide a picture of the research status during the last ten years from 2013 to September 2022. There were 303 articles extracted from the Scopus database. The “VOSviewer” tool was employed to visualize the literature containing the most active scientific journals, countries, and highly used keywords in the field of fibers reinforced concrete. The outcomes showed that “Hybrid Composites”, “Impact Strength”, “Water Absorption”, “Scanning Electron Microscopy”, “Polypropylenes” and “Polymer Composite” have recently emerged as themes related to the applications of KFRC, and grabbed the interest of academics, may also offer future research opportunities. Additionally, according to the frequency of the keywords used, three important research domains associated with kenaf fibers within the concrete in the construction materials field have been identified, including “Mechanical Properties”, “Fiber Reinforced Plastics”, and “Tensile Strength”. Furthermore, the recent studies on the impact of kenaf fiber utilization on the structural performance of reinforced concrete are reviewed. Accordingly, the explanations related to research findings, suggestions for future studies have been provided on the incorporation of kenaf fibers reinforced concrete in civil engineering applications

Elucidating the Effects of Reaction Time on the Physicochemical Characterization of Valorized Synthesized Alumina

Aluminum waste-can management in Malaysia has recently become a serious environmental and public health issue, particularly in metropolitan areas. This has prompted the need to valorize these waste-cans into value-added products using the most economical and environmentally friendly techniques. In this study, the sol–gel technique was used to synthesize high-quality alumina from the aluminum waste-cans collected. From this method, the observed peaks of the synthesized alumina were identified as diaspore (α-AlO(OH)), boehmite (γ-AlO(OH)), aluminum oxide, or gamma-alumina (γ-Al2O3) crystalline structure and corundum. The morphological configuration, microstructure, and functional group properties of the synthesized alumina were evaluated. All the synthesized alumina exhibited a non-spherical shape and appeared to have hexagonal-like shape particles. Moreover, the XRD patterns of the synthesized alumina AL-6-30 and AL-12-30 exhibited a small angle (1–10°) with no XRD peak, which indicated a mesoporous pore structure with no long-range order. The overall results of γ-alumina synthesized from the aluminum waste-cans showed an optimal condition in producing a highly structured γ-alumina with excellent surface-area characteristics. The synthesized alumina exhibited stronger and highly crystalline functional characteristics almost comparable with the commercially available brands on the market