Abstract

To achieve the 1.5 °C climate goal, global aviation must reach net-zero COâ‚‚ emissions around 2050. Yet, aviation is widely regarded as a “hard-to-abate” sector due to its strong reliance on high-energy-density liquid fuels. This paper briefly reviews and compares decarbonization models and pathways published by major organizations such as ICAO, IATA, ATAG and ICCT. Key findings include: (1) Sustainable aviation fuel is viewed across all major scenarios as the primary emissions reduction lever during 2030–2050. (2) Revolutionary technologies such as hydrogen/electric propulsion exhibit the highest level of uncertainty. (3) Operational improvements are unable to fully offset demand growth. (4) Sector-internal measures alone cannot achieve absolute zero emissions by 2050; external market-based measures or carbon dioxide removal will be necessary. The study further notes that current models are evolving toward integrated techno-economic-policy-climate assessments, AI-enhanced interpretable projections, and improved accounting of non-COâ‚‚ effects and socio-economic impacts.

Abstract

Peer-to-peer (P2P) electricity trading has the potential to enhance the integration of renewable energy, increase flexibility, and bolster community resilience; however, the design of settlements still poses a significant challenge. Traditional fiat systems incur ongoing banking and payment service charges, while generic cryptocurrencies carry risks of volatility and systemic issues. This paper introduces EnergiRING Coin, an energy-linked settlement token that is incorporated into the realSES platform, along with a hybrid co-settlement strategy that switches between fiat and token depending on marginal cost differences, employing a brief cooldown period to avoid oscillations. We carry out a year-long agent-based simulation (8,760 hourly intervals; 2,000 diverse agents) under deterministic disturbances, including two significant cryptocurrency crashes, a market rally, and repeated spikes in fiat fees. The physical clearing (hence total welfare) remains unchanged across different regimes, but net results vary: the fiat-only model is inefficient due to fees, the token-only model fails during shocks, and the hybrid model consistently achieves positive net welfare, reduced inequality, and enhanced resilience; not only avoiding losses during downturns but also capturing additional gains during token price rallies. These findings elevate the concept of settlement from a mere back-office function to an essential market-design tool for maintaining stable, efficient, and low-carbon P2P trading, positioning EnergiRING Coin as a viable method to synchronize financial flows with renewable generation and demand-side adaptability.

Abstract

The limited availability of fossil fuel resources and the environmental issues caused by greenhouse gas emissions have underscored the need to adopt renewable energy sources, particularly solar energy. Improving the efficiency of solar energy systems increases productivity, reduces fuel and electricity consumption, and improves air quality. In this study, the governing equations were numerically solved in ANSYS Fluent using the finite volume method (FVM) with the k-ω-SST turbulence model. The thermal–hydraulic performance of a parabolic trough solar collector was investigated using a water-based CuO-SWCNT hybrid nanofluid at nanoparticle volume fractions of 1%, 2%, and 4%, and Reynolds numbers ranging from 4000 to 10000. Two modified twisted tape turbulators with different V-cut numbers and angles were examined. The results showed that the twisted tape with three V-cuts achieved the highest performance evaluation coefficient (PEC) and improved collector efficiency compared to the two-cut design, particularly at higher Reynolds numbers.

Abstract

Dual-stator axial flux permanent magnet motors (DSSR-AFPM) have been widely applied in electric vehicle drive systems due to their high torque density and compact structure. However, most existing DSSR-AFPM motors employ a surface-mounted permanent magnet (SPM) rotor topology, which suffers from the inability to utilize reluctance torque, high harmonic content in the air-gap flux density, and significant torque ripple. To overcome these drawbacks, this paper proposes a novel interior permanent magnet (NIPM) rotor with magnetic isolation slots. Under identical design constraints, the electromagnetic performances of three rotor topologies—SPM, surface-embedded permanent magnet (SEPM), and NIPM—are compared using three-dimensional finite element analysis. The results show that the NIPM rotor achieves a more sinusoidal air-gap flux distribution, reduced torque ripple, and enhanced flux-weakening capability, while maintaining high efficiency over a wide speed range.

Abstract

In deepwater drilling, low-temperature and high-pressure seabed conditions readily promote natural gas hydrate formation, leading to wellbore blockage and operational risks. To mitigate hydrate formation, chemical inhibitors are commonly added to drilling fluids. This study employed an automated visual hydrate reactor under controlled cooling, with real-time monitoring of temperature, pressure, and torque, while methane consumption was quantified using the Peng-Robinson equation. The effects of calcium chloride (CaCl₂, thermodynamic inhibitor) and modified cellulose (CHNF, kinetic inhibitor) were systematically evaluated. Increasing CaCl₂ concentration prolonged nucleation time and reduced nucleation temperature. At 8wt%, the total pressure drop decreased from 5.25MPa (pure water) to 2.46MPa without significant hydrate accumulation; higher concentrations yielded limited additional benefit, and 8wt% was identified as the optimal dosage considering both efficiency and corrosion risk. CHNF displayed a dose-dependent kinetic inhibition effect: at 0.2wt%, the induction time extended to 213 min and nucleation temperature dropped to 8.1°C, whereas 0.1wt% showed negligible effect. Mechanistic analysis suggests that CaCl₂ suppresses hydrate formation by reducing water activity and shifting the gas-liquid equilibrium toward lower temperature and higher pressure, while CHNF delays nucleation and destabilizes hydrate clusters via interfacial adsorption and hydrogen-bond competition. These findings provide practical guidance for optimizing drilling fluid formulations in deepwater operations.