Search Results (900)

Radial Basis Functions (RBFs), since their inception in the 1960s, have emerged as a key tool in digital engineering applications. As interpolators in multidimensional spaces, RBFs play a crucial role both in generic data science problems and in 3D space manipulation. Their ability to represent large 3D datasets in a mesh-free manner has established them as the standard approach for data mapping and mesh deformation. A fast implementation of RBFs is essential to fully exploit this mathematical approach in digital engineering applications. This paper provides an overview of fast RBF methods in digital engineering and presents practical applications in the field of Computer-Aided Engineering (CAE), highlighting the role of RBFs in the development of a digital twin capable of real-time interaction with 3D structural components; after detailing the workflow for a simple plate with a hole, the method is demonstrated for the structural redesign of a scooter engine connecting rod and for the interactive conceptual design of a CubeSat. Full article

This paper develops a numerical methodology to evaluate the influence of seabed properties on the acceleration response of resiliently mounted equipment subjected to underwater explosions (UNDEX). The approach is based on a coupled acoustic–structural analysis (CASA), implemented in ABAQUS CAE, to simulate the transient response of a foundation–resilient–mass system installed on a patrol vessel. The study considers multiple seabed configurations, including rigid, rock, sand, muddy, and muddy-over-sand conditions, with the objective of quantifying how reflected shock waves modify the dynamic loading environment. A far-field non-contact UNDEX scenario is modelled, accounting for both incident and seabed-reflected pressure waves. The response of the mounted equipment is evaluated in terms of transmitted accelerations at different installation locations along the hull. The results demonstrate that seabed characteristics play a dominant role in shaping the vibration response. Rigid and rock seabeds induce significant amplification of acceleration levels, reaching values up to twice those of the free-field condition, whereas softer seabeds lead to a marked attenuation effect. The proposed framework enables a systematic assessment of seabed-induced effects on onboard equipment and provides quantitative support for the design and placement of resilient mounting systems in naval applications. Full article

At present, research on the long-term stability of multi-cavern coordinated injection–production operations for salt cavern compressed air energy storage (CAES) remains limited. Large-capacity energy storage utilizing multiple interconnected salt caverns has become an inevitable development trend for modern CAES power stations, highlighting the necessity and importance of stability evaluation and design optimization for underground salt cavern storage clusters. Based on the Anning 350 MW CAES demonstration project, this paper takes the abandoned salt caverns of the project as research objects. A three-dimensional geological and cavern model is established using the FLAC3D numerical simulation method, and stability analysis is carried out under static conditions and three long-term gas injection and production scenarios (the pressure conditions are provided by ground-based equipment). The characteristics of the plastic zone, displacement, stress distribution, and volume shrinkage of the caverns are systematically investigated. The results show that under static conditions, the internal pressure significantly controls the development of the plastic zone, and the caverns are generally stable at pressures above 4 MPa. During long-term operation, the plastic zones of each cavern gradually expand, displacements accumulate continuously, and stresses tend to stabilize after an initial accumulation period. After 30 years of operation, no through-going plastic zones appear in any cavern, and all volume shrinkage rates are below 30%. Among the three cases, Case 1 exhibits the best stability, while enhanced monitoring is required for local high-stress regions in Case 3. This study verifies that the salt cavern development for the Anning CAES project is safe and controllable during long-term operation. The layout spacing of caverns is reasonably designed and fully satisfies the stability requirements of salt cavern CAES power stations. The research results can provide a technical guarantee for the construction of the first CAES power station in Yunnan Province and also offer a reliable reference for the design and construction of similar multi-cavity salt cavern CAES projects. Full article

Olive pomace is a major side stream originating from olive processing for the production of olive oil. This waste material bears a load of polyphenolic antioxidants, and thus it might serve as a source of precious phytochemicals. This work had as its objective the development of an extraction process for the efficacious recovery of polyphenols from dried olive pomace (dOP), employing eco-friendly extraction media. To this end, environmentally benign solvents were first compared for their efficiency in obtaining increased yields in total polyphenols, and 40% aqueous isopropanol was selected as the best-performing mixture. Further examination of the role of acidification showed that mineral acid addition (sulfuric, hydrochloric) had a rather negative effect on polyphenol yield. To the contrary, incorporation of oxalic acid into the solvent at a 10% level provided significantly higher extraction yield (p < 0.05), which reached 27.1 ± 1.1 mg caffeic acid equivalents (CAE) per g dOP. This solvent system (40% isopropanol/10% oxalic acid) was additionally scrutinized for its effectiveness by studying the role of process severity and response surface optimization. Out of both approaches, it was demonstrated that polyphenol extraction yield, but also antiradical activity, was directly correlated with residence time and temperature, within the limits tested. Moreover, a high correlation between polyphenol concentration and antiradical activity was also revealed. Liquid chromatography-tandem mass spectrometry analyses showed that the extract obtained with the solvent system used (40% isopropanol/10% oxalic acid) was characterized by the presence of both hydroxytyrosol and the flavone luteolin (242.1 and 178.6 μg g⁻¹ dOP, respectively), but, in the absence of isopropanol, the extract produced was largely dominated by hydroxytyrosol (4629.7 μg g⁻¹ dOP). Thus, it was concluded that the solvent system could fundamentally diversify extract composition. It is proposed that, when combined with integrated biorefinery technologies, this approach could effectively contribute to reducing environmental impacts while enabling the production of valuable natural antioxidants or platform chemicals that are vital for the food, pharmaceutical, and cosmetic industries. Within the broader context of sustainable food waste management, such strategies might be key elements of a circular economy framework. Full article

Against the background of global carbon reduction initiatives and ongoing energy transition, this study addresses the technical challenges of constructing salt cavern storage facilities in bedded salt formations. Typical bedded salt rocks in Southwest China were taken as the research object, and systematic core sampling and multi-dimensional laboratory tests were conducted to investigate their geomechanical and petrophysical properties. The tests included mechanical experiments such as direct shear, uniaxial and triaxial compression, as well as physical property measurements including permeability, porosity, SEM, XRD, and mercury intrusion porosimetry (MIP). The results show that halite exhibits excellent plasticity and tight sealing performance, interlayers have high compressive strength, and mudstone is characterized by significant brittleness. All lithologies possess low permeability and dense internal structures. For this reason, they are well suited for salt cavern energy storage utilization. Furthermore, the research findings provide key basic data and a solid scientific basis. This study supports the construction of salt cavern gas storage and compressed air energy storage (CAES) plants in bedded salt rock areas. Full article

Aircraft maintenance scheduling is a critical task in air transportation and national defense security, characterized by complex multi-step procedures, strict precedence dependencies, and multi-resource constraints involving personnel skills and equipment availability. Traditional scheduling methods and standard metaheuristic algorithms often suffer from insufficient model adaptability, poor population diversity, premature convergence, and complex encoding schemes that require frequent feasibility checks. To address these challenges, this paper proposes a comprehensive optimization framework based on the Resource-Constrained Project Scheduling Problem (RCPSP) model. A decimal priority-based encoding method is introduced to replace traditional integer permutation encoding, significantly reducing computational complexity and enhancing search space continuity. Furthermore, an improved hybrid Particle Swarm Optimization algorithm integrating reverse learning and partial random operations (RL-PSO) is developed. The reverse learning mechanism expands the global search space by generating reverse particles, while partial random operations maintain population diversity and prevent premature convergence. The proposed framework converts priority encoding into feasible schedules through a priority sorting and left-shift resource allocation strategy. Simulation experiments on maintenance tasks involving up to 50 aircraft demonstrate that RL-PSO achieves optimization accuracy of 332 min, convergence speed of 92.07 s, and stability of 2.8843 min in standard deviation, which are superior compared to standard PSO, Simulated Annealing, and Teaching–Learning-Based Optimization combined with the serial schedule generation scheme (SSGS). The method effectively balances global exploration and local exploitation, making it suitable for complex, large-scale aircraft maintenance scenarios. Future work will extend the framework to multi-objective optimization and dynamic scheduling environments. Full article

The optimisation design of agricultural machinery is shifting from offline, experience-driven engineering towards adaptive, data-driven, and closed-loop intelligent optimisation. Conventional approaches based on computer-aided engineering (CAE), empirical testing, mathematical modelling, and static multi-objective optimisation have provided an important engineering foundation, but they remain limited under unstructured field conditions involving soil heterogeneity, crop variability, climatic disturbance, and nonlinear machinery–environment interactions. This review systematically examines the evolution of intelligent optimisation design for agricultural machinery from conventional simulation-based methods to artificial intelligence (AI)- and digital twin (DT)-enabled paradigms. First, mathematical modelling, response surface methodology, discrete element method (DEM), computational fluid dynamics (CFD), multi-body dynamics (MBD), heuristic algorithms, and early AI-assisted surrogate optimisation are reviewed to clarify their contributions and limitations. Second, frontier enabling technologies are analysed, including agriculture-specific large models, generative AI, lightweight edge intelligence, deep reinforcement learning (DRL), embodied AI, federated learning (FL), and privacy-preserving computing. Third, system-level applications integrating DT and AI are discussed, with emphasis on full-lifecycle machinery optimisation, device–edge–cloud collaborative control, multi-agent fleet coordination, predictive maintenance, and Agriculture 5.0-oriented intelligent equipment systems. Key deployment bottlenecks are further identified, including sim-to-real inconsistency, virtual–physical mismatch in DTs, edge-side trade-offs among accuracy, latency, energy consumption, and cost, insufficient validation standards, and economic adoption barriers. Finally, a 2025–2030 roadmap is proposed, highlighting large-model–DT closed loops, control biomimetics, green low-carbon optimisation, and trustworthy human–machine symbiosis for sustainable Agriculture 5.0. Full article

Salt cavern Compressed Air Energy Storage (CAES) is one of the critical technologies for energy storage and an important infrastructure supporting the construction of new power systems and facilitating the achievement of the dual carbon goals. The salt rock resources in China are primarily composed of continental strata salt rocks, characterized by high heterogeneity, well-developed thin-layer interbedding, dissolution resistance among different lithologies, and significant creep variations. These features, to some extent, limit the improvement of wellbore construction accuracy, the reliability of abandoned well sealing, the safety of natural gas storage operations, and enhancements in gas injection–brine displacement efficiency. This study takes the continental bedded salt rock in the Dawenkou Basin as the research object and adopts a method combining theoretical analysis and field engineering verification to improve the systematic construction technology system, covering the whole process of drilling engineering, abandoned well plugging, the design of an injection and brine extraction device, and gas injection and brine drainage. The research results optimize four key technologies, including precise wellbore trajectory control, dual-section milling, and multi-stage redundant plugging of abandoned wells and long-term anti-corrosion completion with laser cladding, and dual-mode adaptive gas injection and brine drainage, and improve the technical system from wellbore construction to salt cavity formation. This study can provide valuable theoretical references and engineering demonstration guidance for underground space development projects in similar salt basins in China. Full article

Traditional Chinese brick-and-stone archways are not merely architectural products shaped by geographical constraints; they also embody a highly rational structural logic. Drawing on the unique earthen environment of the Loess Plateau and the region’s traditions of brick-and-stone construction, the Jinzhong region of China has developed a distinct system of archways. Consequently, to deconstruct the mechanical wisdom inherent in the traditional building techniques of the Jinzhong region, this study selected residential buildings in Qi County and Pingyao, as well as Qing Dynasty (1636–1912 AD) official architecture, as case studies. Through field investigations into the masonry techniques of three typical vault forms—the single-centre arch, the double-centre arch, and the four-centre arch—the study revealed their evolutionary characteristics in terms of geometric form. Static numerical simulation analysis was conducted using the Abaqus CAE 2025 (Dassault Systèmes, Vélizy-Villacoublay, France) platform. The study found that, under a simulated surface load of 0.027 N/mm², different arch profiles exhibited significant quantitative mechanical differences, and their stress distributions and deformation thresholds showed distinct scenario-specific tendencies. The results show that, compared to a semicircular arch, the official double-centred arch reduces maximum displacement by approximately 20%, and the maximum principal stress decreased from 1.35 MPa to 1.215 MPa, effectively mitigating the risk of cracking at the arch crown. With this high sectional stiffness and displacement-constraining capability, it supports the high load requirements of defensive city fortifications. Compared to the Pingyao gentle-type four-centre arch, its maximum displacement increased by only about 10%, and the maximum principal stress rose by only about 8%. Therefore, given similar mechanical performance but considering construction feasibility, the official double-centred arch was selected for the construction of defensive city fortifications. Furthermore, although the stress concentration at the corners (arch feet) of the Pingyao gentle-curved four-centred arch is approximately 4.8% higher than that of the pointed four-centred arch, its spatial utilization is improved by 15–20%; This geometric trade-off achieved through composite curvature maximizes interior clear space while maintaining structural stability, aligning with the functional requirements of guyao architecture for large-span living spaces. Meanwhile, the semicircular vaults of Qi County demonstrate universal value in low-load residential door and window components due to their low construction threshold. These quantitative data and qualitative observations indicate that the evolution of traditional forms is not merely an esthetic pursuit, but rather a precise optimization of structural performance within the constraints of material strength. This coupled relationship between “geometric form, load-bearing mechanism and usage context” confirms the inherent principles of resource efficiency and performance balance within traditional building systems. The quantitative assessment framework established in this study provides scientific guidance, grounded in construction logic, for the preventive conservation and precise reinforcement strategies of historic masonry structures. Full article

The growth of commercial aerospace enterprises (CAEs) has injected new vitality into the entire aerospace system. Nevertheless, there remains a research gap concerning the entrepreneurial behavior of these enterprises, which is primarily driven by commercial demands and technological innovation. Drawing on network embeddedness theory and complex system theory, this study proposes a conceptual framework that links the structural and relational embeddedness of aerospace system subnetworks to entrepreneurial behavior, while examining the mediating roles of perceived organizational resilience and perceived environmental uncertainty. The moderating role of transformational leadership is evaluated using the trait activation theory. A two-phase quantitative design was employed, combining Partial Least Squares Structural Equation Modeling (PLS-SEM) and fuzzy-set Qualitative Comparative Analysis (fsQCA). Empirical analysis using a sample of 265 CAEs in China revealed several key findings: (1) the structural position of CAEs within the aerospace system network, along with informational resources formed through relationships, can enhance perceived organizational resilience and reduce perceived environmental uncertainty, thereby promoting entrepreneurial behavior; (2) entrepreneurs’ transformational leadership can effectively enhance the positive relationship between perceived organizational resilience and their entrepreneurial behavior; (3) two distinct configurations lead to high entrepreneurial behavior among CAEs. The study concludes with corresponding theoretical and practical implications. Full article

Underground Compressed Air Energy Storage (CAES) is a promising large-scale energy storage technology, yet its long-term operational safety is constrained by progressive tensile damage accumulation in lining structures under cyclic thermo-mechanical loading. Conventional steel-lined caverns are costly, while ordinary reinforced concrete linings require excessive reinforcement due to their limited tensile capacity, compromising the economic viability of CAES. This study proposes a Reinforced-Steel Fibre Concrete (R-SFC) lining as the structural load-bearing layer of CAES caverns, in which the steel fibres provide tensile and crack-propagation resistance and the rebars contribute supplementary tensile capacity. A 2D coupled thermo-mechanical damage-plasticity finite element model was developed in COMSOL Multiphysics and verified using published in situ monitoring data from operating CAES caverns. Parametric analyses of the steel fibre volume fraction, lining thickness, rebar diameter, and cavern diameter were then performed. The results show that the R-SFC lining significantly improves crack propagation resistance, reducing the maximum tensile damage by 41.3% relative to conventional reinforced concrete while lowering steel consumption. Within the lining–rock system, the concrete lining and the surrounding rock jointly resist the radial compressive load, while the steel fibres and rebars bear the hoop tensile stress. A thickness-to-diameter ratio of 1/8 to 1/5 is identified as the recommended geometric design range to balance lining damage against surrounding rock loading. Finally, an MOPSO algorithm coupled with a PSO-BP surrogate model is employed to balance lining tensile damage against cavern dimensions, yielding optimised parameter combinations particularly suitable for cavern diameters around 4 m. The study findings may provide a new lining solution and design reference for cost-effective and high-reliability underground gas storage. Full article

Background/Objectives: Antimicrobial resistance, an evolutionarily entrenched microbial capacity amplified by extensive antibiotic exposure, has increased the burden of difficult-to-treat infections caused by priority pathogens such as Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus. In this study, we assessed whether phytochemical-rich extracts from fully ripe Rosa canina pseudo-fruits (WF) and fully developed Colchicum autumnale flowers (CA) can provide combined antioxidant, antibacterial, and antibiofilm effects against multidrug-resistant clinical isolates. Methods: Plant materials were processed using seven extraction systems spanning non-polar to polar conditions (n-hexane, ethyl acetate, n-butanol, aqueous, 40% ethanol, 60% ethanol, and enzyme-assisted hydrolysis). Fractions were quantified for total phenolics, flavonoids, and tannins, evaluated for antioxidant capacity (DPPH and FRAP), tested for antibacterial activity (disc diffusion and MIC/MBC), and assessed for inhibition of early biofilm attachment. Differences among extraction methods and fractions were analyzed using standard comparative statistics (group comparisons across solvents/fractions), and relationships between chemical composition and bioactivity were examined using correlation-based analysis. Results: Extraction strategy emerged as the main determinant of bioactivity across endpoints. The WFE/ENZ fraction maximized phytochemical recovery (TPC 203.34 ± 11.55 mg GAE/g DW; TFC 35.67 ± 3.06 mg QE/g DW; TTC 53.00 ± 2.65 mg TAE/g DW) and showed strong antioxidant performance (DPPH IC₅₀ 33.60 ± 0.02 μg/mL; FRAP A₇₀₀ 1.90 ± 0.010 at 250 μg/mL). Antibacterial effects were strongest in polar fractions, particularly hydroethanolic and enzyme-assisted extracts, while n-hexane fractions were consistently weakest. Across eight clinical isolates and three reference strains, MIC values ranged from 0.04875 to 6.25 mg/mL for WF extracts and 0.0975–12.5 mg/mL for CA extracts. In the biofilm model, suppression of early attachment was most consistent for CAE/E60–ENZ and WFE/E40–E60–ENZ fractions. Conclusions: Correlation analysis indicated that antibacterial potency aligned primarily with flavonoid levels in R. canina pseudo-fruits and with tannin content in C. autumnale material. Overall, these results support hydroethanolic and enzyme-assisted extraction as rational strategies to enrich polyphenol-dense fractions with convergent antioxidant, antibacterial, and antibiofilm activity, reinforcing plant-derived matrices as a structured discovery space for developing complementary antimicrobial solutions beyond conventional antibiotics. Notably, this is among the first studies to evaluate the antibacterial potential of C. autumnale plant material in this context and to comprehensively assess R. canina pseudo-fruit extracts against multidrug-resistant clinical. Full article

Today, renewable energy is receiving increasing global attention. However, the operation of such energy systems is associated with several challenges, including natural uncertainty and intermittency at different times of the day. Furthermore, to overcome these challenges, there is an increasing interest in developing energy storage systems. Compressed air energy storage (CAES) is considered a promising, cost-effective, and environmentally friendly technology. The present study proposes a novel CAES system distinct from conventional designs. The proposed storage system can store energy by feeding the excess electrical energy to a motor to drive a large-diameter piston to compress and store air in a container. Then, the energy is extracted when needed by releasing the piston to drive the generator back. This study evaluates the feasibility via a thermodynamic model of all components. We examine the effects of (i) piston speed and piston-air volume ratio, (ii) initial pressure, and (iii) container volume. We also assess how container volume scales with the maintained initial pressure. Results are compared against an adiabatic baseline. The results demonstrate that near-isothermal compression/expansion can improve energy density and storage efficiency by generating two times more recoverable work than the adiabatic in the same volume, and an efficiency of 76% can be reached, while the realistic efficiency achieves around 50%. It also shows that the volume of the container for an amount of energy depends on the initial pressure maintained before the charging cycle. As a result, when the initial pressure increases, the volume of the container required decreases, and for the same volume, the results show that more energy can be stored by maintaining the initial pressure. Therefore, this system could be considered an attractive solution to the integration of intermittent renewable energy sources. Full article

In recent years, the deployment of robots in human-centric environments has necessitated the development of artificial skins that integrate safety and durability. Traditional damage detection often relies on raw signal thresholds, lacking the functional integration of touch, pain, and damage found in biological systems. This study proposes a bio-inspired artificial skin model that separately evaluates these three states through a spatio-temporal anomaly detection framework. We developed an unsupervised model combining a Convolutional Autoencoder (CAE) and Convolutional LSTM (ConvLSTM) to learn the latent representations of tactile maps from intact skin. By quantifying spatial reconstruction and temporal prediction errors, the system generates individual scores for touch, pain, and damage. Pain is defined as an abstract signal of instantaneous abnormality, while damage is identified as a persistent structural deviation. We implemented a dynamic thresholding mechanism mimicking biological sensitization and recovery, with damage detection gated by a pain-flag constraint to minimize false positives. Experimental results across various conditions—including incisions (3–6 cm) and abrasions (10–30 times)—demonstrate that the model can distinguish between momentary noxious stimuli and sustained structural degradation. Quantitative evaluation shows that the proposed model achieves an Area Under the Curve (AUC) of 0.653, outperforming a threshold-based baseline and maintaining zero false positives under strong, non-damaging contact. Specifically, the system successfully mimics biological aftereffects and the pain-gating mechanism, where damage is only assessed in the presence of a pain-related trigger. This research provides a scalable, software-driven foundation for robot self-protection that overcomes the implementation constraints of hardware-dependent neuromorphic systems. Full article

A generalized eigenvalue formulation is developed for the free vibration analysis of anisotropic rectangular plates with rotationally restrained edges using the finite integral transform method. For free vibration problems, casting the governing equations into a generalized eigenvalue problem is particularly advantageous because it enables the direct and systematic extraction of multiple natural frequencies and their associated mode shapes within a unified framework, while avoiding the need for assumed trial functions or solution searching near initial guesses. In the present study, a two-dimensional sine integral transform is introduced into the governing equation of anisotropic plates with bending-twisting coupling, and the mechanical description of rotationally restrained boundary conditions is incorporated simultaneously, thereby converting the original partial differential boundary value problem into a generalized eigenvalue problem. The corresponding analytical solution is then established through the finite integral transform framework. The accuracy and reliability of the proposed method are verified through comparisons with finite element results and published data. Based on the obtained analytical solution, the effects of boundary conditions, rotational stiffness coefficients, aspect ratio, and key stiffness components on the vibration characteristics of anisotropic rectangular plates are further examined. The present study provides an effective analytical framework for free vibration analysis of anisotropic plates with nonclassical rotational restraints and offers theoretical support for the dynamic design and optimization of advanced composite plate structures. Full article