The quantification of the extent and dynamics of land-use changes is a key metric employed to assess the progress toward several Sustainable Development Goals (SDGs) that form part of the United Nations 2030 Sustainable Development Agenda. In terms of anthropogenic factors threatening the conservation of heritage properties, such a metric aids in the assessment of achievements toward heritage sustainability solving the problem of insufficient data availability. Therefore, in this study, 589 cultural World Heritage List (WHL) properties from 115 countries were analyzed, encompassing globally distributed and statistically significant samples of “monuments and groups of buildings” (73.2%), “sites” (19.3%), and “cultural landscapes” (7.5%). Land-cover changes in the WHL properties between 2015 and 2020 were automatically extracted from big data collections of high-resolution satellite imagery accessed via Google Earth Engine using intelligent remote sensing classification. Sustainability indexes (SIs) were estimated for the protection zones of each property, and the results were employed, for the first time, to assess the progress of each country toward SDG Target 11.4. Despite the apparent advances in SIs (10.4%), most countries either exhibited steady (20.0%) or declining (69.6%) SIs due to limited cultural investigations and enhanced negative anthropogenic disturbances. This study confirms that land-cover changes are among serious threats for heritage conservation, with heritage in some countries wherein the need to address this threat is most crucial, and the proposed spatiotemporal monitoring approach is recommended.

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In this article, a novel fan-out panel-level printed circuit board (PCB)-embedded package for phase-leg silicon carbide (SiC) metal-oxide-semiconductor field-effect transistor (MOSFET) power module is presented. Electro-thermo-mechanical co-design was conducted, and the maximum package parasitic inductance was found to be about 1.24 nH at 100 kHz. Compared with wire-bonded packages, the parasitic inductances of the PCB-embedded package decreased at least by 87.6%. Compared with blind via structure, the thermal resistance of the proposed blind block structure reduced at most by about 26%, and the stress of the SiC MOSFETs decreased by about 45.2%. Then, a novel PCB-embedded packaging process was developed, and three key packaging processes were analyzed. Furthermore, effect of PCB-embedded package on static characterization of SiC MOSFET was analyzed, and it was found that: 1) Output current of PCB-embedded package was decreased under a certain gate-source voltage compared to SiC die; 2) Miller capacitance of SiC MOSFET was increased thanks to parasitic capacitance induced by package; and 3) compared with SiC die, nonflat miller plateau of the PCB-embedded package extends, and as drain-source voltage increases, the nonflat miller plateau extends. Lastly, switching characteristics of the PCB-embedded package and TO-247 package were compared. The results show that the PCB-embedded package has smaller parasitic inductances.

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Supersonic civil aircraft is of a promising area in the development of future civil transport, and aircraft propulsion system is one of the key issues which determine the success of the aircraft. To get a good conceptual design and performance investigation of the supersonic civil aircraft engine, in this article, a fast, versatile as well as trust-worthy numerical simulation platform was established to analyze the Mach 4 turbine-based combined cycle (TBCC) engine concept so as to be applied to the supersonic civil aircraft. First, a quick and accurate task requirement analysis module was newly established to analyze the mission requirement of the Mach 4 supersonic civil aircraft. Second, the TBCC engine performance simulation model was briefly presented and the number of engines on the supersonic civil aircraft was analyzed, considering single engine inoperative. Third, the Stone model and the DLR method were investigated to estimate the engine jet noise and the NO x emission of the Mach 4 supersonic civil aircraft. Finally, a multiobjective optimization tool made up of a response surface method and a genetic algorithm was developed to optimize the design parameters and the control law of the TBCC engine, in order to make the Mach 4 supersonic civil aircraft engine with better performance, lower noise, and lower emissions. The uniqueness of the developed analysis tool lies in that it affords a numerical simulation platform capable of investigating the task requirement analysis module of the supersonic civil aircraft, engine jet noise prediction model, and the NO x emission prediction model, as well as a multiobjective performance optimization tool, which is beneficial for the conceptual design and performance research of Mach 4 supersonic civil aircraft’s propulsion system.@en

This paper presents the performance assessment of a novel turbofan engine using two energy sources: Liquid Natural Gas (LNG) and kerosene, called Multi-Fuel Hybrid Engine (MFHE). The MFHE is a new engine concept consisting of several novel features, such as a contra-rotating fan to sustain distortion caused by boundary layer ingestion, a sequential dual-combustion system to facilitate “Energy Mix” in aviation and a Cryogenic Bleed Air Cooling System (CBACS) to cool the turbine cooling air. The MFHE has been envisaged as a propulsion system for a long-range Multi-Fuel Blended Wing Body (MFBWB) aircraft. In this research, we study the uninstalled characteristics of the MFHE covering three aspects: 1) the effects of CBACS on the High Pressure Turbine (HPT) cooling air requirement and its consequence on the engine cycle efficiency; 2) the cycle optimization of the MFHE; 3) the performance of the MFHE at a mission level. An integrated model framework consisting of an engine performance model, a sophisticated turbine-cooling model, and a CBACS model is used. The parametric analysis shows that using CBACS can reduce the bleed air temperature significantly (up to 400 K), thereby decreasing the HPT cooling air by more than 40%. Simultaneously, the LNG temperature increases by more than 200 K. The hybrid engine alone reduces the CO2 emission by about 27% and the energy consumption by 12% compared to the current state-of-the-art turbofan engine. Furthermore, the mission analysis indicates a reduction in NOx emission by 80% and CO2 emission by 50% when compared to the baseline aircraft B-777 200ER.
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As an evolutional concept of variable cycle engine, the adaptive cycle engine draws widely attention with high expectations. It combines a variable geometry schedule and component matching principles to demonstrate its advantages such as avoiding severe inlet spillage drag and the wide variable cycle characteristics. Thus, this paper aims at equilibrium running principle analysis on an adaptive cycle engine at variable operating modes, deriving the equilibrium running equations of an adaptive cycle engine for the first time, and exploring the physical essence of components matching principle on the basis of a newly developed nonlinear component-based adaptive cycle engine performance model. It uncovers the physical essence of components matching relationships and provides mathematical derivation of equilibrium running principles which lay theoretical foundation of the variable geometries modulation schedule and overall performance optimization on an adaptive cycle engine.@en