In the current work, the Flamelet Generated Manifold (FGM) method is applied with large-eddy simulation (LES) to investigate the effect of methane on dual-fuel (DF) spray ignition. The diesel surrogate n-dodecane is injected as the so-called pilot fuel into selected lean methane–air mixtures, ranging from ϕ_CH4=0 to ϕ_CH4=0.75, at engine relevant conditions. The operating conditions are those of the completely characterized Engine Combustion Network (ECN) Spray A configuration, for which the modeling approach adopted in the present study was extensively validated. The specific purpose of this study is to extend and validate the FGM approach for dual-fuel combustion. In order to understand the interplay of chemistry and mixing, the ignition behavior of selected cases is investigated. It is found that both low and high temperature combustion (LTC and HTC, respectively) are increasingly retarded by higher values of ϕ_CH4, while the induction time between LTC and HTC is relatively insensitive compared to the ignition delay time (IDT). Analysis reveals a more prominent role of mixing for increased ϕ_CH4. The development of LTC and HTC are quantitatively analyzed for different cases. The transition from LTC to HTC is found to be highly correlated with the evolution of lift-off length (LOL), which on its turn is seriously affected by ϕ_CH4. The local flame behavior is analyzed via chemical explosive mode analysis (CEMA), suggesting a clear flame propagation due to diffusion towards lean mixtures after the ignition of the pilot fuel. Besides, it is found that diffusion helps to stabilize the flame in leaner mixtures, which is more important in DF combustion. The results show FGM to be a promising tool in modeling the DF sprays.

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This paper presents an overview of a sub-orbital flight demonstration with a 183 GHz and 540–600 GHz limb-sounding instrument aboard a stratospheric ballooncraft. The 183 GHz band provides soundings of stratospheric H 2 O and is implemented with a hybrid CMOS-InP receiver architecture which provides excellent sensitivity while remaining compact (162 g) and offering an extremely low DC power consumption (0.62 W). The 540–600 GHz channel sounds stratospheric O 3 and uses a combination of a CMOS local oscillator, GaAs Schottky mixer and micro-electro-mechanical-system (MEMS) RF switch for calibration, again offering competitive form factor (1.4 Kg) and low DC power consumption (6.6 W) compared to prior instruments. The instrument was flown on the NASA Reck-Tang Limb-sounding Experiment (ReckTangLE) ballooncraft and performed atmospheric soundings across New Mexico and Northwestern Texas on Oct. 17 2019.@en

We demonstrate that trimethylamine borane can exhibit desirable piezoelectric and pyroelectric properties. The material was shown to be able operate as a flexible film for both thermal sensing, thermal energy conversion and mechanical sensing with high open circuit voltages (>10 V). A piezoelectric coefficient of d₃₃≈10–16 pC N⁻¹, and pyroelectric coefficient of p≈25.8 μC m⁻² K⁻¹ were achieved after poling, with high pyroelectric figure of merits for sensing and harvesting, along with a relative permittivity of (Formula presented.) 6.3.

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This research is focusing on China’s new concept of “blue economy” and the integration of it into the country’s sustainable development efforts. Under the Blue Economy framework, Chinese ocean-based economic development has experienced an obvious acceleration over the last three decades, which has increased sustainable development capabilities. Meanwhile, national plans are being implemented in order to promote future oceanic sustainable development. The Qingdao Port is the iconic example of the Blue Economy practices resulting from the Chinese oceanic development strategy and it has indeed been quite successful in its development until now since the introduction of the Blue Economic Zone and the Belt and Road Initiative (BRI) programmes. Moreover, the sustainable experience of the Qingdao port shows an optional reference of the blue economic plan to other ports expecting an optimal ocean development. Finally, some challenges and opportunities will be discussed for further research and practical improvements.@en