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Simplified deflection calculation method for PC box girder bridges with corrugated steel webs using asynchronous-pouring-construction technology
No full textFunding Information: The authors gratefully acknowledge the financial support provided by the National Natural Science Foundations of China ( 52378127 , 51978081 , 52211530037 ), the Natural Science Foundation of Hunan Province, China ( 2022JJ10049 , 2021JJ30712 ), the Open Fund of Key Laboratory of Bridge Engineering Safety Control by Hunan Provincial , Department of Education (Changsha University of Sciences and Technology, Grant No. 13KA04 ), and the Fund of Postgraduate Research Innovation Project (Changsha University of Sciences and Technology, Grant No. CXCLY2022039 ). Publisher Copyright: © 2024 Elsevier LtdThis paper introduces an asynchronous-pouring-construction (APC) technology for long-span prestressed concrete (PC) box girder bridges with corrugated steel webs (CSWs). The technology makes full use of the CSWs to support the hanging basket. The top slabs, bottom slabs and CSWs are divided into multiple independent working platforms to improve the construction efficiency. In present study, the authors conducted a theoretical analysis of the deflection in PC girder bridges with CSWs using APC technology. A simplified deflection calculation model was developed on the basis of the principle of section equivalence for different segment division. Consequently, a series of theoretical formulas was proposed considering additional shear deflection induced by bending moments. These formulas could be utilised to calculate the configuration and the total deflection of the bridge during APC process, facilitating the pre-camber application to eliminate the deflection and to ensure the closure of the bridge. Moreover, parallel finite element analyses (FEA) and field monitoring tests were conducted to validate the simplified calculation method. The comparison results showed that the calculated deflections using the simplified method agreed well with the FEA and test results. The proportion of shear deflection in the total deflection ranged from 17% to 39% from the forward movement of basket to the pouring slabs, the shear deflection could not be negligible. The segments' length had large effect on the deflection of the CSWs with 50 mm at the maximum cantilever state in this bridge case study, and the deflection induced by the pouring concrete of the slabs accounted for approximately 70% of the total deflection. The additional shear deformation due to bending moment at the end of area A (composite section with both concrete top and bottom slabs and CSWs) was basically the same as that in area B (composite section with bottom slab and CSWs). Therefore, the simplified method which takes into account the additional shear deformation of the segments in area A without considering area B was able to satisfy the engineering accuracy. In short, in comparison to traditional analytical methods and FEA, the proposed method could predict the deflection more efficient within accept accuracy.Peer reviewe
Graphene-based optically transparent metasurface for microwave and terahertz cross-band stealth utilizing multiple stealth strategies
No full textFunding Information: This work was supported by the National Natural Science Foundation of China (NSFC) ( 62071291 ). Q. Li and J. Zhang contributed equally to this work. Publisher Copyright: © 2024 Elsevier LtdStealth, as a miraculous physical phenomenon, has received widespread attention from the scientific and engineering communities for a long time. Optically transparent stealth devices are of significant importance for the stealth capabilities of aircraft windshields and solar panels. However, the current stealth implementations are limited to a single frequency band due to the strong dispersion of passive materials so that cross-band stealth still remains challenging. In this paper, a novel cross-wavelength stealth strategy is proposed based on multi-layer graphene transparent metasurface, which achieves stealth both in microwave and terahertz frequency bands. Strong resonance is designed to achieve high absorption in the microwave band and diffuse scattering is employed for RCS reduction in the terahertz band. Materials such as graphene and ITO are employed to achieve optical transparency and flexibility of the metasurface. The above design is implemented using numerical simulations and experiments, and the results are in good agreements. This design method that integrates multiple stealth strategies opens up a new approach for cross-band stealth, with potential applications in countering advanced electromagnetic detection.Peer reviewe
ANN-RSM based multi-parametric optimisation and modelling of H2 and syngas from co-gasification of residues from oil palm plants
No full textPublisher Copyright: © 2024 The Institution of Chemical EngineersDespite their abundance, lignocellulose biomass co-gasification studies especially that of oil palm biomass are scarcely reported. In this study, the frond and trunk of the oil palm tree are co-gasified under different conditions. Experimental results were validated, modelled, and optimised with the aid of RSM and ANN for the syngas and H2 results. The optimum yield of syngas and H2 were found to be 49.01 %, and 23.26 % respectively when operated at 900°C with particle size of 2.6 mm and blending ratio of 1:1. ANOVA yielded satisfactory P-values in the case of RSM with 95 % confidence level. The Bayesian regularisation-based ANN with a 3–10–2 topology (3 inputs, 10 hidden neurons, and 2 outputs) has shown to be a very successful and resilient model, as indicated by its significant coefficient of determination R2 of more than 0.95. The selected ANN structure demonstrates an efficient framework for capturing complicated interactions among the data. The model's relevance is shown by its ability to provide statistically relevant predictions. Furthermore, its endurance under varying situations demonstrates its reliable effectiveness, implying a capacity to generalize effectively to new, existing data. Based on the findings of the suggested BP-based ANN, the proposed model may be used in co-gasification processing industries to make critical evaluations of process operating conditions.Peer reviewe
Think like a robot : How interactions with humanoid service robots affect consumers’ decision strategies
No full textFunding Information: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Publisher Copyright: © 2023 Elsevier LtdService robots are beginning to be a popular choice in the frontline of customer service. It is important to explore how interacting with humanoid service robots (vs. human employees) influences consumers' following behaviors. Specifically, the present research examines how interacting with humanoid service robots (vs. human employees) influences consumers' emotional intensity and subsequent decision strategies. Through four experiments, the current research demonstrates that interacting with humanoid service robots (vs. human employees) induces a lower emotional intensity, which in turn promotes a relative reliance on cognitive reasoning (vs. affective feeling) in consumers’ decision-making such as hotel room choice. Furthermore, this research identifies the moderating role of service provider gender and anthropomorphism tendency. The main effect disappears when the service robot is female (vs. male) and when consumers have a higher anthropomorphism tendency. The present research provides significant implications for both robot literature and the tourism and hospitality business.Peer reviewe
Fracture toughness and crack propagation in anisotropic triangular lattices
No full textPublisher Copyright: © 2025This study investigates the fracture toughness, critical energy release rate, and crack growth resistance (R-curve) of anisotropic triangular lattices. Anisotropy is introduced by tailoring the lattice microstructure through variations in the thickness ratio t̄ of struts, while maintaining a constant relative density. The mode I fracture response is analyzed using the finite element method, based on a boundary layer technique. The simulations demonstrate a non-monotonic dependence of the fracture toughness on t̄, with peak values occurring at distinct thickness ratios depending on the crack orientation relative to the lattice topology. The corresponding critical energy release rate exhibits the same non-monotonic trend, but with a distinct dependence on t̄. The crack propagation analysis reveals that anisotropy strongly affects both the crack growth resistance and the corresponding crack growth path. Specifically, when the initial crack line is perpendicular to the vertical struts, increasing t̄ enhances resistance, and the crack tends to propagate along the initial crack line. On the other hand, when the initial crack line is parallel to the vertical struts, increasing t̄ first leads to a reduction in both fracture toughness and crack growth resistance, accompanied by a transition from slanted propagation to penetration along the initial crack line. However, beyond a critical thickness ratio (t̄≈1.50), the penetration growth persists only up to a limited distance from the initial crack tip, after which crack propagation resumes along a slanted path. This variation in the crack propagation process significantly enhances the crack growth resistance. Altogether, the results provide key insights into the fracture response of anisotropic lattices, offering practical guidelines for designing architected materials with improved toughness and controlled crack propagation.Peer reviewe
Investigating the impact of ventilation primary frequency control on indoor climate and cognitive performance in office settings
No full textPublisher Copyright: © 2025 The AuthorsRenewable energy sources pose challenges to power grid stability because they lack the synchronous inertia provided by traditional generators. To address this, demand-side primary frequency control (PFC) has emerged as a potential solution. Previous studies have suggested that ventilation fans could be utilized as demand-side loads for PFC. As far as we are aware, limited research has explored how such implementations impact indoor air quality and human cognitive ability. This study evaluates the short-term impact of a primary frequency control ventilation method using a controlled testing chamber. Two experimental conditions are compared: the first condition is with a constant ventilation rate based on Finnish guidelines, the other is with a variable rate governed by the frequency control method, which adjusts ventilation fan power to help balance short-term frequency deviations in the grid. We measured indoor environmental parameters, including humidity, temperature, CO2, PM2.5, PM10, and total volatile organic compounds (TVOC), and evaluated participants’ (N=20) cognitive performance using standardized tests under two conditions in a climate chamber. Our results suggest that the method has an acceptable impact on indoor air quality, and there is no significant change in the cognitive performance of the participants. These findings demonstrate the feasibility of using ventilation fans for PFC in practical use while supporting the UN sustainable development goal: Affordable and Clean Energy.Peer reviewe
How Well Do DeepSeek, ChatGPT, and Gemini Respond to Water Science Questions?
No full textThis study aims to evaluate the performance of three prominent LLMs, DeepSeek R1, ChatGPT-4o, and Gemini 2, in addressing key questions within four core fields of hydrology and water science: machine learning and optimization, remote sensing, flood modeling, and sediment transport. LLMs’ responses are systematically compared to benchmark responses derived from review articles in the respective fields. To assess the LLMs’ efficiency, a novel evaluation rubric is introduced in this study, incorporating four key criteria: relevancy, accuracy, authenticity, and novelty. Findings revealed that each model can address the core aspects of the benchmark questions. DeepSeek R1 achieved the highest overall scores in machine learning and optimization, flood modeling, and sediment transport, while ChatGPT-4o demonstrated superior performance in remote sensing. Notably, DeepSeek R1 and Gemini 2 exhibited the lowest response similarity in 95% of the evaluated questions, whereas ChatGPT-4o and Gemini 2 showed the highest similarity in 70% of cases.Peer reviewe
Bio-based foams with multifunctional photothermal, fire-resistant, and CO2 capture properties
No full text| openaire: EC/H2020/949648/EU//ModelComTo meet the growing demand for sustainable, fire-resistant, and thermally functional materials, this study develops multifunctional bio-based foams composed of naturally abundant clay minerals and cellulose nanofibers (CNFs). The foams are fabricated via freeze-drying and carbonized to enhance photothermal activity and flame resistance. Varying clay-to-CNF ratios reveal that clay improves structural retention during pyrolysis, reducing volume shrinkage from 85 % in neat CNF foams to 10–14 % in hybrids. The carbon–clay network significantly enhances compressive modulus and energy absorption, while thermogravimetric analysis confirms improved thermal stability. Despite carbonization, thermal conductivity remains low (0.041–0.058 W m−1 K−1), supporting insulation applications. The carbonized foams exhibit strong photothermal response, reaching surface temperatures above 80 °C under solar irradiation, and demonstrate CO2 adsorption up to 12.4 ± 0.6 mg g−1. Life cycle assessment (LCA) highlights substantial environmental advantages, reducing climate change potential from 19.18 to 0.76–1.16 kg CO2-eq·kg−1 in clay–CNF hybrids, alongside benefits in acidification, ecotoxicity, eutrophication, water use, and land occupation. These findings establish clay–CNF carbon foams as competitive alternatives to both synthetic insulation materials and pure nanocellulose porous structures, offering high volume retention upon carbonization while achieving a balanced combination of thermal, mechanical, fire-safe, and environmental performance.Peer reviewe
Hydrogen storage model for decarbonization of constant industrial processes
No full textPublisher Copyright: © 2025 The Author(s)The decarbonization of industrial processes will require large quantities of green hydrogen produced with renewable energy. The use of variable renewable energy for hydrogen production will, in turn, necessitate large-scale hydrogen storage to ensure the constant availability of hydrogen. In existing energy models, hydrogen storage is typically included as a ‘black box’ unit that simplifies the behavior of hydrogen during the operation of a storage cycle. In this study, a high-fidelity hydrogen gas storage model is developed. The model considers the behavior of hydrogen as a real gas during storage operations, a defining advancement compared to previous studies, and utilizes hourly data sets of renewable energy production. The model is first demonstrated on a baseline case located in Finland, where 121 MW of wind power capacity supplies an annual hydrogen demand of 6000 tonnes, mandating a hydrogen storage capacity of 575 tonnes. Next, a sensitivity analysis reveals that increasing wind power capacity or adding solar power to the energy mix decreases the storage requirement significantly. On the other hand, increasing the minimum storage pressure or reducing the electrolyzer capacity both increase the required storage capacity. Finally, the baseline case was used to compare storage technologies available in the Finnish context, and lined rock caverns were found to be the most cost-efficient option with a reasonable storage volume. Overall, the study concludes that significant storage capacities and thus investments are required for the industrial utilization of green hydrogen. Therefore, it is essential that the behavior of hydrogen as a real gas is considered when sizing storage systems.Peer reviewe
Separating belief in meaning of life from the personal experience of meaning in life : Different relations with religiosity and well-being
No full textPublisher Copyright: © 2025 The AuthorsWe investigate whether belief in the meaning of life (that life as such has meaning) and the psychological experience of meaning in one's own life constitute distinct empirical constructs; We also aim to clarify how we should define this belief. To this aim, we develop the Belief in the Meaning of Life Questionnaire (BiMoLQ) in Study 1 (N = 315), confirming its factor structure, psychometric properties, and validity in Studies 2 (N = 285) and 3 (N = 436). Overall, the results confirm that meaning of life and meaning in life are distinct constructs. Studies 1 and 2 show that the former is more related to religiosity and spirituality, while the latter is more related to well-being and emotional experiences. Study 3 suggests that directly manipulating the presence of meaning of life and meaning in life in fictional scenarios differently impacts both constructs. We conclude that future research on the role of meaning in human psychology should differentiate these constructs, as they are conceptually and empirically separate, and that the belief in the meaning of life might play a unique role within individuals' mental life.Peer reviewe