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[Objective] To improve the drying quality of pumpkins. [Methods] This study conducted experiments on hot air drying, vacuum drying, and combined hot air-vacuum drying, these drying characteristics were evaluated and compared based on unit energy consumption, rehydration ratio, and color difference indicators. Combining BP neural network model with genetic algorithm, combined with entropy weight and weighted scoring method, a multi-objective comprehensive optimization was carried out for the combined hot air-vacuum drying of pumpkins. [Results] Under the same conditions, the highest drying efficiency was hot air drying; And the findings revealed that at drying temperatures was 55 ℃, with a moisture content transition point of 30%, the combined drying method reduced the drying time by 52.63%, compared to vacuum drying. The lowest unit energy consumption was vacuum drying; The worst rehydration performance was hot air drying. The best color was vacuum drying. The optimal drying parameters determined by the genetic algorithm combined with a BP neural network model were a hot air drying temperature of 65 ℃, conversion point moisture content of 50%, and vacuum drying temperature of 56.050 9 ℃. Verification experiments demonstrated that the average relative errors between the genetic algorithm optimized values and the experimental values for unit energy consumption, rehydration ratio, and color difference were 2.5%, 5.53%, and 4.84%, respectively, all lower than 6%. [Conclusion] The combined hot air-vacuum drying of pumpkin integrates the advantages of both hot air drying and vacuum drying, and combined with BP neural network genetic algorithm model can optimize the process parameters for pumpkin hot air vacuum drying.

Identifying key road segments and prioritizing their protection to enhance the resilience of road networks against crisis events remains a pressing issue. In this paper, complex network theory is adopted to determine the importance ranking of road segments and analyse how to select the road segments that need to be rehabilitated in the case of insufficient budget. This study will provide three different methods to assess the importance of road segments, and with the help of user equilibrium model for traffic demand allocation, calculate the system travel time after rehabilitation to evaluate, compare, and analyse different rehabilitation schemes, and then get the rehabilitation scheme with better performance. Meanwhile, it is investigated whether the optimal road segment rehabilitation combination will change under different budget levels. The results of the case study finally show that the rehabilitation set determined by the Clustering Coefficient and the betweenness is better, which can provide practical guidance on how to select the prioritized rehabilitation segments.

A flapping foil, which mimics the flapping wings of birds and the locomotion of aquatic organisms, is an alternative to a conventional turbine for the harvesting of renewable energy from ubiquitous flows in the atmosphere, oceans, and rivers. In this work, the energy harvesting performance of flapping foils with attached flaps at the trailing edge is numerically studied by using an immersed boundary–lattice Boltzmann method (IB-LBM) at a Reynolds number of 1100. Three different configurations are considered, namely, a clean NACA0015 foil, a NACA0015 foil with a single flap, and a NACA0015 foil with two symmetric flaps. The results show that the flap attached to the trailing edge is able to enhance the energy harvesting efficiency, and the two symmetric flaps can achieve more enhancements than its single-flap counterpart. The mechanism of such enhancements is attributed the separation of the interactions of vortexes generated at the upper and bottom surfaces of the foil. To further obtain the optimal configurations of the two symmetric flaps, the angle between the two flaps (α) and the length ( l f ) of the flap are systematically studied. The results show that the optimal energy harvesting performance is achieved at α = 60 ∘ and l f = 0.1 c (c denotes the chord length of the foil). Compared with the baseline case, namely, the clean NACA foil, the optimal configuration can achieve an improvement of efficiency up to 19.94%. This study presents a strategy by adding two symmetric flaps at the trailing edge of the foil to enhance the energy harvesting performance of a flapping foil, which contributes to advancing the development of simple and efficient clean energy harvesting by using a flapping foil. [ABSTRACT FROM AUTHOR]