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Natural fiber reinforced polymer composites (NFRPCs) have garnered significant attention as lightweight alternatives to conventional composites for household, building, automotive, and industrial applications. However, their susceptibility to thermal degradation, ignition, heat release, and smoke formation remains a severe limitation in fire-sensitive areas. This review critically examines the thermal degradation behavior, inherent flame retardant properties, and flame retardant modification strategies of natural fiber composites, with special emphasis on lignocellulosic plant fibers, protein-based animal fibers, and calcium carbonate-rich biological shells. The influence of cellulose, hemicellulose, lignin, keratin, fibroin, and inorganic mineral elements on degradation pathways, volatile evolution, and protective residue formation is examined in depth. Particular attention is paid to the char-generating capability of lignin-rich materials (e.g., wood bark, fruit and seed shells), the specific degradation behavior of protein-based fibers, and the endothermic and barrier-forming properties of mineral-rich biological shells. The review also discusses phosphorus-nitrogen intumescent systems, mineral flame retardants, nanofillers, bio-based additives, surface treatments, and hybrid reinforcement strategies, describing their roles in condensed-phase protection, gas-phase flame inhibition, thermal shielding, and smoke suppression. Experimental results show that reinforcement chemistry, polymer matrix properties, additive interactions, and the structural integrity of protective residues are key factors influencing char production and heat release. However, improved thermal stability or higher residue yield does not necessarily translate to better flame retardancy or mechanical integrity under fire conditions. These techniques offer promising routes to developing fire-safer, mechanically dependable, and resource-efficient natural fiber composites for home and industrial applications.
Abstract Aspergillus section Flavi produces naturally occurring secondary metabolites called aflatoxins. Maize is vital to the livelihood of poor people and the rural economies of many developing countries. Aflatoxin contamination is prevalent in maize, making it one of the most susceptible grains. This study compares pre- and post-harvest practices used by farmers in two agroecological zones in Ghana and relates them to practices that prevent aflatoxin contamination of maize. It was conducted in Ghana's forest and savannah agroecological zones between September 2019 and March 2020. 800 individuals were selected for the study using a multistage selection approach that adhered to probability sampling techniques. A semi-structured questionnaire was the primary method and data collection tool. A 1kg maize sample was obtained from farmers for aflatoxin analysis. Pre-harvest practices such as weed control, fertiliser application, irrigation, and aflasafe application were used by farmers in both ecological zones. Chemical weed control was used by most farmers (64.9%) in both zones. Fertiliser application was common among farmers in the savannah zone (97%), while pest control was common in the forest zone (87%). Only 3.2% of the farmers use irrigation, and 3.1% use aflasafe. Some post-harvest practices in both zones included drying, sorting, shelling, and packaging. Most farmers (87.9%) allowed their maize to dry fully on the farm before harvesting. The main method of shelling in the forest zone was beating (74.9%), while shellers were used in the savannah zone (90.6%). Most farmers (74.0%) used sorted grains as animal feed, and 25.0% as food. 3.9% of farmers used Purdue Improved Crop Storage (PICS) bags. Farmers should be educated on the right pre-harvest interventions, such as timely weeding, proper irrigation, fertiliser application, and aflasafe application, as well as post-harvest interventions, including correct drying methods, proper packaging during storage, and suitable storage conditions.
Generation IV nuclear reactor designs, like molten salt reactors (MSRs), provide passive safety and improved economics by dissolving fuel with liquid salt and moving it through the heat exchangers and core. Notwithstanding the technology's enormous potential, there is a dearth of comprehensive studies that use bibliometric and systematic review techniques to examine the development and patterns of the MSR technology. This paper adopts the bibliometric review approach using the VOSviewer and Bibliometrix package in R software to analyze the global research landscape of MSR technology between 2000 and 2024. The findings show that international collaboration is increasing in the field of advanced reactor designs and fuel cycle technologies, notably involving MSRs, thorium fuel cycles, and advanced simulation models. The research clusters indicate a multidisciplinary nature involving nuclear chemistry, reactor physics, materials science, and computational modelling. This notwithstanding, challenges such as salt purity, corrosion-resistant materials, and long-term safety are still barriers. Future research should therefore optimise fuel cycles and make advances in core designs for mini reactors while transmutating waste to reduce the radioactive inventory. Also, simulation tools should be developed further, especially in areas such as isotope transmutation and neutron transport, to increase the scalability, efficiency, and sustainability of MSR.
Low-voltage mini-grids play a crucial role in expanding electricity access for rural and remote communities. However, they continue to face technical and operational barriers that hinder their performance and reliability. This study reviewed the evolution of research on technical challenges in low-voltage mini-grids from 2005 to 2025. Using the PRISMA approach, data were extracted from the Scopus database, yielding 155 publications for bibliometric analysis. Bibliometrix in R Studio was used to examine publication trends, geographical contributions, and thematic evolution, while qualitative synthesis identified key engineering and operational constraints. The findings revealed a steady increase in research outputs since 2020, driven by global policy commitments, including Sustainable Development Goal 7 and the Paris Agreement. Persistent technical barriers include voltage and frequency instability, inadequate power quality monitoring, inefficient integration of energy storage, poor control coordination, and limited system design optimisation. African nations contribute less to global research despite being most affected by energy poverty, highlighting capacity and funding gaps. The study highlights the need for integrated solutions combining smart control, hybrid storage, and grid-interconnection technologies to enhance resilience and reliability. For policymakers and practitioners, the findings advocate for investment in research, capacity building, and locally tailored technical standards designed for resource-constrained contexts. This review provides a comprehensive evidence base to guide future research and policy directions aimed at achieving sustainable, technically robust, and financially viable mini-grid systems for universal energy access.
This study assessed the global research trends on embodied energy in buildings over the past two decades (2003-2023), emphasising its role in climate change mitigation. The core problem addressed is the continued overlook of embodied energy and carbon in the built environment, despite their increasing share in total life cycle emissions as buildings become more operationally efficient. This issue is critical since the construction sector contributes to global greenhouse gas emissions, mostly in urbanising and climate-vulnerable regions like Africa. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses method, 303 relevant publications were identified from the Scopus database and analysed with the R Studio-based Bibliometrix software package. The findings revealed a surge in publications post-2016, demonstrating keen global attention to sustainability frameworks such as the Paris Agreement and Sustainable Development Goal targets. Key themes identified include life cycle assessment, circular economy, and carbon mitigation, with embodied carbon emerging as a dominant concept. The study revealed a disproportionate concentration of research in developed countries, with limited contributions from Africa, highlighting a pressing need for localised studies and context-sensitive policy interventions. In addition, the study identified innovative strategies such as bio-based materials, prefabrication, and retrofitting as viable pathways for reducing embodied energy. These findings are significant for informing global climate policy, building standards, and the African Union Agenda 2063 aspiration for sustainable infrastructure. Moreover, the findings could serve as a roadmap for future research, capacity building, and policymaking to decarbonise the building sector globally and regionally.
