Energy efficiency has become a pressing concern for economies undergoing rapid industrialisation while simultaneously managing growing energy demand. This study investigates how low carbon energy transition and energy access affect the energy intensity of GDP across the Next Eleven (N-11) economies over the period 1990–2024. Energy intensity is defined as total primary energy consumption per unit of real economic output. Low carbon energy transition is proxied by the combined share of natural gas, nuclear energy, and renewable energy in total energy consumption. Energy access is measured by the proportion of the national population with access to electricity. The study incorporates carbon emissions, population size, urbanisation, gross fixed capital formation, and trade openness as additional control variables. Panel data for all eleven N-11 countries were sourced from the World Bank, the International Energy Agency, and Our World in Data. To account for heterogeneous effects at different points of the energy intensity distribution, the empirical analysis applies the Method of Moments Quantile Regression technique. Preliminary diagnostic tests confirm cross-sectional dependence, slope heterogeneity, mixed orders of integration, and long-run cointegration among the study variables. Several findings emerge from the estimation. Energy access exerts a positive and statistically significant effect on energy intensity across most quantiles. This result is not surprising: expanding electricity access tends to raise aggregate energy demand in the near term, before any accompanying efficiency gains have time to take hold. Low carbon energy transition, by contrast, reduces energy intensity, which is consistent with the argument that cleaner energy sources raise the productive efficiency of energy use. Carbon emissions are positively associated with energy intensity, while gross fixed capital formation contributes to efficiency by lowering it. Urbanisation and population produce effects that vary across the energy intensity distribution rather than following a single direction. Overall, these findings point to a structural tension in development-oriented energy policy. Expanding access without coordinating efficiency measures risks locking in high energy intensity at precisely the moment when N-11 economies have the most to gain from low carbon transition.
Lithium-rich layered oxides (LRLOs) are regarded as promising cathode materials for next-generation Lithium-ion batteries (LIBs). However, they face challenges such as structural instability, voltage decay and capacity that hinder their practical application and commercialisation. This study presents the first comprehensive bibliometric analysis of global LRLO cathode research covering the period 2005–2025 using 1048 publications retrieved from the Scopus and Web of Science databases. The results show that China leads globally in publication output, institutional contributions, and international collaborations. The lifecycle analysis indicates that LRLO research has evolved into a mature yet rapidly expanding scientific domain, while Lotka's Law confirms the establishment of a stable scientific community. The major research themes include "lithium-ion batteries", "high-capacity", "cathodes", "electrochemical performance", "surface modification", and "oxygen redox chemistry", indicating a shift from materials synthesis to mechanism-based optimisation. These findings provide strategic insights into the current development of LRLO cathodes and highlight AI-assisted materials design as a promising opportunity to accelerate their optimisation and commercialisation.
The inefficient utilization and disposal of lignocellulosic Post-Extraction Herbal Residues (PEHR) of Azadirachta indica leaves (AIL) have pose environmental challenges and limit their potential as sustainable energy resources. Despite the availability of herbal extraction residues, limited studies have investigated post-extraction Azadirachta indica leaf residues through an integrated experimental, process-simulation, optimization, scale-up, and techno-economic framework. Therefore, this study presents a laboratory proof-of-concept-experimentation and also evaluates the technical performance as well as economic feasibility of biogas production from PEHR of AIL through anaerobic digestion. Aspen Plus simulator, ASPEN Cost analyzer and CAPCOST as well as Excel Microsoft user-defined software were used for the simulation, scale-up, equipment sizing and economic analysis of laboratory-proof-of-concept experimentation. Response Surface Methodology (RSM) was applied for process modelling and optimization study. A process simulation model (PSM) closely biogas yield (194.60 mL/gVS) with a low deviation (8.11%), confirming model reliability. Response Surface Methodology (RSM) based on Box–Behnken Design demonstrated strong predictive capability (R² = 0.9994) and identified temperature and pressure as significant factors influencing biogas yield. Optimal conditions (40°C, 0.5 bar, 22.6 days) produced a maximum yield of 512.43 mL/gVS with high desirability (0.986). Techno-economic analysis indicated strong financial feasibility, with a total capital investment of 456,800.98 USD and annual net profit of 104,434.92 USD. Key indicators—NPV (276,708 USD), IRR (19%), ROI (22.86%), and payback period (4.37 years)—confirm economic attractiveness. Sensitivity analysis further revealed that profitability is most influenced by biogas yield and market price. The findings demonstrate the potential of AIL-PEHR for valorization through anaerobic digestion and provide a basis for further pilot-scale investigation and industrial implementation.
Edible salts locally mined and processed in Awe and Keana communities of Nasarawa State, Nigeria are consumed without proper purification, thus posing possible health risks to consumers. This study evaluates metals/metalloids and natural radionuclides concentration in 75 composite salt samples from 15 different sources. Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Gamma Spectrometry equipped with NaI (Ti) detector, were used to analyze metals/metalloids and natural radionuclides, respectively. The results showed that the average levels of Al, As, Cd, Co, Cr, Cu, Mn, and Pb in the unrefined salts exceeded regulatory permissible limits, with several containing 238U. In contrast, refined salt samples showed most metal and natural radionuclide levels below the regulatory permissible limits. Hazard Index levels for most unrefined salts exceeded unity, indicating potential non-carcinogenic health risks for both adults and children. Specific exposure to high cancer risk comes from As, Cd, Cr, and Ni in the unrefined salt samples studied. The presence of Cr (average CR values = 1.04 × 10− 4) in the investigated refined salts posed an increased carcinogenic risk in children. Principal component analysis (PCA) revealed that metal contamination in the salts was from multiple sources. The evaluated radiological health hazard indices of the salt samples were within the permissible limit set by the UNSCEAR, indicating no significant ionizing radiation health risk. Therefore, it is recommended that future studies should consider organ – specific cancer risk assessment to provide more detailed toxicological insight on the consumption of unrefined edible salts from Awe and Keana.
This research investigates whether the Elelen Field, a mature gas reservoir in the Niger Delta, can be repurposed for effective CO2 sequestration. By integrating historical production records with seismic data and well logs, we mapped the reservoir's petrophysical architecture, focusing on Sands A and B. Our analysis shows that Sand A remains a prime candidate for injection, maintaining high-end effective porosity (0.24-0.32) and exceptional permeability values reaching up to 7916 mD. Sand B likewise shows promising storage potential. Calculations indicate that Sand A can hold roughly 5.6 Mt of CO2 while Sand B offers a capacity of 1.3 Mt. Crucially, the presence of a substantial shale caprock suggests the field has the structural integrity needed to prevent leakage. Given the current decline in gas production, leveraging the existing infrastructure at Elelen for carbon storage appears both technically feasible and timely. However, before full-scale injection begins, we suggest moving to dynamic simulations to confirm how the CO2 will behave over several decades.
