Search Results (36,679)

The increasing deployment of humanoid robots in indoor environments such as smart factories, laboratories, offices, and hospitals poses new challenges to millimeter-wave wireless communication systems. Existing human body obstruction models, while effective at characterizing pedestrian-induced signal attenuation, are not designed to directly capture the structural geometry, material composition, and controlled mobility of humanoid robotic platforms. In this work, we first reproduce a well-established human-body-based propagation model under comparable indoor conditions and subsequently extend this hybrid framework to controlled humanoid-based scenarios by combining double knife-edge diffraction (DKED) with a modified street-canyon reflection model operating at 28 GHz. Compared to existing human-based studies, the proposed approach explicitly incorporates the material properties of the humanoid robot’s envelope through a calibrated correction factor and accounts for its controlled lateral movements. An indoor measurement campaign using three programmable humanoid robots was conducted to evaluate the model. Experimental results show that humanoid robots can reproduce attenuation trends and obstruction dynamics consistent with those reported in prior human-body blockage studies, while offering improved repeatability and greater experimental control. The proposed framework provides a practical and reproducible tool for modeling indoor millimeter-wave channels under controlled humanoid-based experimental conditions, in environments involving mobile robotic agents. Full article

The increasing interest in sustainable materials has led to the development of bio-based composites for additive manufacturing applications. This study aimed to investigate the influence of key printing parameters and new-generation infill patterns together on the maximum compressive force of PLA–wood bio-composites produced by Material Extrusion. By optimizing this material, low-cost wood-like products can be produced. New-generation 3D infill patterns (octet, cubic-subdivision, and lightning which is a biomimetic infill pattern) infill densities, printing temperatures, and layer heights were selected as variables/factors, and the Taguchi method was applied for design of the experiment. The signal-to-noise ratio and Analysis of Variance were used to evaluate the statistical significance and contribution of each parameter to the mechanical response. The signal-to-noise ratio indicated that the optimal printing settings were as follows: printing temperature, 205 °C; infill density, 80%; infill pattern, octet; and layer height, 0.2 mm (7123.4 N). ANOVA results showed that infill density was the most significant factor affecting maximum compressive force at 60%, while infill pattern also exhibited a notable effect. According to these results, infill density and infill pattern are the most important factors for achieving high compressive strength. These findings suggest that optimizing infill architecture and density can improve the mechanical performance of PLA–wood composites, also they can offer assistive design guidelines for lightweight and eco-friendly components. Full article

Phosphogypsum, the primary solid waste from the wet-process phosphoric acid industry, poses significant environmental and health risks due to large-scale stockpiling. To promote its resource utilisation, this study systematically evaluated the solidification and stabilisation performance of phosphogypsum–coal fly ash cementitious material (PAC) for Cr(VI)-contaminated soil under high-chloride conditions. Phosphogypsum reactivity was enhanced via mechanical activation and high-temperature calcination. An orthogonal experimental design was employed to analyse the effects of multiple factors—including calcination temperature and duration—on compressive strength and heavy metal leaching behaviour. Results show that PAC prepared from coal ash calcined at 600 °C for 3 h exhibits excellent mechanical properties and Cr(VI) stabilisation efficacy under high-chloride conditions, achieving a maximum compressive strength of 28.75 MPa and a Cr(VI) leaching concentration as low as 15.69 μg/L. Microstructural characterisation revealed the synergistic formation of a dense framework between C–S–H gel and calcium aluminate, conferring superior mechanical strength. Substitution and chelation mechanisms of Cl⁻ ions played a key role in enhancing corrosion resistance. This study provides theoretical support and technical guidance for the high-value utilisation of phosphogypsum-based materials in remediating saline–alkali-contaminated soils. Full article

Efficiently separating propene and propane is paramount for the chemical industry but notoriously difficult due to their minimal size and volatility differences. Here, an efficient strategy to overcome this separation challenge was demonstrated through the design of bimetallic zeolitic imidazolate framework (ZIF)-based mixed-matrix membranes (MMMs). Thin-film composite (TFC) membranes were fabricated by integrating monometallic ZIF-8, ZIF-67, and a synergistic bimetallic ZIF-8-67 into a uniquely formulated ionic liquid–cellulose acetate (IL–CA) polymer matrix. Structural and morphological analyses confirmed the high crystallinity of the ZIF fillers and their seamless integration within the polymer. The resultant ZIF-8-67/IL-CA membrane exhibited notable separation performance, surpassing its monometallic counterparts by a threefold increase in both C₃H₆ permeance and C₃H₆/C₃H₈ ideal selectivity relative to the base membrane. Under industrially relevant mixed-gas testing, the membrane achieved a competitive separation factor of eight for propene over propane. These findings reveal that the strategic integration of bimetallic nodes in ZIFs can unlock synergistic properties unattainable with single-metal frameworks. This work presents a robust and scalable platform for developing next-generation membranes that defy conventional performance trade-offs, paving the way for efficient membrane-based olefin/paraffin separations. Full article

The traditional mantis search algorithm (MSA) suffers from limitations such as slow convergence and a high likelihood of converging to local optima in complex optimization scenarios. This paper proposes an improved mantis search algorithm (IMSA) to overcome these issues. An adaptive probability conversion factor is designed, which adaptively controls the proportion of individuals entering the search phase and the attack phase so that the algorithm can smoothly transition from large-scale global exploration to local fine search. In the search phase, a probability update strategy based on both subspace and full space is designed, significantly improving the adaptability of the algorithm to complex problems by dynamically adjusting the search range. The elite population screening mechanism, based on Euclidean distance and fitness double criteria, is introduced to provide dual guidance for the evolution direction of the algorithm. In the attack stage, the base vector adaptive probability selection mechanism is designed, and the algorithm’s pertinence in different optimization stages is enhanced by dynamically adjusting the base vector selection strategy. Finally, in the stage of sexual cannibalism, the directed random disturbance update method of inferior individuals is adopted, and the population is directly introduced through the non-greedy replacement strategy, which effectively overcomes the loss of population diversity. The experimental results of 29 test functions on the CEC2017 test set demonstrate that the IMSA exhibits significant advantages in convergence speed, calculation accuracy, and stability compared to the original MSA and the five best meta-heuristic algorithms. Full article

The rapid advancement of flexible and stretchable electronics has raised new demands for conductive materials with high conductivity and excellent mechanical properties. Compared to traditional conductive materials, gallium-based liquid metals exhibit a compelling set of attributes—including intrinsic deformability, high conductivity, good thermal conductivity, and a liquid state at or near room temperature—that address the critical requirements for conductors in flexible and stretchable electronics. However, the broader application of gallium-based liquid metals is limited by intrinsic challenges, such as oxidation tendency and high surface tension, while their multifunctional potential remains to be fully explored and developed. This paper provides a comprehensive review of gallium-based liquid metals, spanning from their fundamental concepts including intrinsic properties and processing characteristics (oxidative layer/droplet engineering) and functionalization techniques to their diverse applications in flexible electronics. It concisely summarizes key factors, existing issues, and challenges encountered during the design, research, and application of gallium-based liquid metals, aiming to provide guidance and assistance for subsequent research and applications. Full article

The digitalisation of education has introduced new possibilities for inclusive teaching practices, particularly in supporting students with special educational needs (SEN). While digital tools have demonstrated potential to enhance learning outcomes and engagement for these students, the role of school leadership in fostering teachers’ digital competence remains underexplored. The aim of the study is to investigate the association between school leadership, as rated by teachers, and teachers’ self-reported digital competence in supporting students with SEN. To this end, cross-sectional data from 285 Swedish teachers enrolled in special education training programmes have been used. The data were collected through the SELFIE survey, a European Commission tool designed to assess schools’ digital capacity. A stepwise linear regression analysis was conducted to examine the association between perceived school leadership and teachers’ self-reported digital competence in supporting students with SEN, controlling for teacher collaboration, infrastructure and equipment, and demographic variables. The results show a consistent and significant positive relationship between school leadership and teachers’ digital competence, even when other factors are accounted for. Teacher collaboration also contributed positively, though to a lesser extent, while infrastructure and equipment and demographic variables showed no significant effect. The study contributes knowledge by showing that teachers’ digital competence development depends not only on individual efforts but also on organisational factors, such as supportive school leadership, highlighting the importance of recognising school leadership as vital alongside digital resources in schools. Given the cross-sectional design, the findings should be interpreted cautiously and not as evidence of causal relationships. These findings suggest that school leadership is important in enabling teachers to use digital technologies to support students with SEN, highlighting practical and policy implications for strengthening school leadership in developing teachers’ digital competence in supporting students with SEN. Full article

Temperate fruits, mostly comprising pome, stone fruits, and berries with immense nutritional benefits and a storehouse of various therapeutic phytochemicals, are prone to several physiological disorders immediately after harvest. The etiology, symptom progression, and decay incidence are influenced by pre-harvest and post-harvest factors, causing significant economic loss with respect to both the energy and economics invested. Respiratory end products, ethylene generation, and enzymatic activities interact to influence the metabolic response and associated biochemical variation. Advanced packaging technologies have emerged as innovative solutions to curtail these post-harvest problems. The design and development of novel packaging technologies need to critically understand the respiratory behavior of the fruits and their associated metabolic functions. A desirable polymer or packaging technology should exhibit enhanced barriers to the gases while providing adequate support to the fruit matrix. In addition, it should also fulfill the role of environmental sustainability and the circular economy. The outcome of this review will highlight the importance of proper post-harvest procedure, appropriate pretreatment, packaging matrix selection, and the storage conditions for effective and enhanced shelf-life storage. Therefore, this review was structured in two phases; the first phase discusses the biochemical understanding of the fruit during storage and transit in response to stress factors. The next phase highlights the various packaging interventions (polymers, biodegradable films, edible coatings, smart packaging, nano-packaging) taken to address these issues, with a key focus on shelf-life enhancement. Further, the key limitations of each technology are appraised. Full article

To address complex connections in prefabricated concrete structures, a novel joint connecting a prefabricated concrete-filled steel tubular column and a composite beam is proposed. Pseudo-static tests on six scaled specimens and ABAQUS finite element analyses were conducted to investigate seismic mechanisms, focusing on slab effects and beam-bottom configurations. Experimental results show the joints exhibit plump hysteretic curves. The composite beams displayed distinct shear-dominated failure, while the stiffened column remained intact. With an average ductility coefficient of 2.84 and an ultimate equivalent viscous damping coefficient of 0.207, the specimens demonstrated excellent deformation and energy dissipation capabilities. The slab’s flange effect significantly enhanced negative bearing capacity, causing mechanical asymmetry. Comparatively, the steel plate beam bottom configuration offered superior stiffness and stability over the reinforcement beam bottom configuration. Sensitivity analysis revealed that bearing capacity is highly sensitive to beam parameters (e.g., longitudinal rebar strength, connector length) but less sensitive to column parameters. Notably, the bearing capacity of the beam bottom configuration using reinforcement increases significantly with concrete strength and reinforcement ratio, whereas the beam bottom configuration using a steel plate shows marked insensitivity to these factors. These findings clarify the load transfer mechanism and support the seismic design of prefabricated structures. Full article

Magnetic fluid sealing is a novel sealing technology wherein magnetic fluids play a pivotal role in the sealing process. The yield stress of the magnetic fluid directly affectsits sealing performance and is governed by multiple interdependent factors. Conventional approaches that evaluate the effect of a single parameter while keeping other parameters constant are insufficient to fully characterize the relative contributions of each parameter to the yield stress. In this study, we investigate the preparation factors affecting the yield stress of kerosene-based magnetic fluids and propose a parameter sensitivity analysis method based on orthogonal experimental design to determine the optimal combination of factor levels within the studied range. The sensitivity of key preparation factors affecting the yield stress of kerosene-based magnetic fluids was determined via range and variance analyses of the orthogonal experimental data. The factors, ranked in descending order of sensitivity, were surfactant (C₁₈H₃₄O₂) dosage, precipitant (NH₃·H₂O) dosage, and deionized water (H₂O) volume. Moreover, the effects of different levels of the same factor were analyzed using multiple approaches. These findings provide a theoretical foundation for optimizing the preparation of magnetic fluids and enhancing their sealing performance. Full article

Digital storytelling (DST) is an innovative pedagogical approach that integrates multimedia creation, personal narrative, and autonomy in L2 education. Yet, its influence on learner engagement remains underexplored in asynchronous delivery modes and non-conventional language learning settings, common in post-pandemic instructional practice. This study thus examines the engagement patterns of 34 student-teachers of English in an afterschool asynchronous DST task about teacher identity. The study further scrutinises their emotional engagement, given its impact on other engagement domains, and its relevance for online instructional design. Data were collected through a background information questionnaire, a validated student engagement questionnaire, and semi-structured interviews that focused on emotional engagement. Questionnaire data were analysed quantitatively using descriptive statistics and repeated measures ANOVA, and interview data were examined qualitatively using thematic analysis and specific emotional engagement-related frameworks. Results indicated participants’ higher cognitive and behavioural engagement, and lower emotional engagement. Their emotional engagement comprised positive emotions and anxiety, which emerged from specific subjective task values, autonomy, and task affordances in interaction with self-imposed personal standards and perceived digital skills. These findings challenge the common conceptualisation of emotional engagement merely as positive affect in L2 tasks and signal the importance of task- and learner-related factors in an engagement-driven online L2 pedagogy. Full article

To enhance the assessment accuracy of tunnel face instability risks of active collapse during shield tunneling, this study establishes a novel unified analytical framework that couples the effects of unsaturated transient seepage induced by excavation drainage with soil stratification and heterogeneity. Grounded in unsaturated effective stress theory, the framework explicitly incorporates matric suction into the Mohr–Coulomb failure criterion via suction stress and apparent cohesion. By employing a horizontal two-layer nonhomogeneous soil model and solving the one-dimensional vertical Richards’ equation, an analytical solution for the face drainage boundary is derived to quantify the spatiotemporal evolution of suction stress and apparent cohesion. Subsequently, the critical support pressure is evaluated using the upper bound theorem of limit analysis, incorporating a horizontal layer-discretized rotational failure mechanism and the power balance equation. The validity of the proposed framework is confirmed through comparative analyses. Parametric studies reveal that in the upper hard and lower soft strata, the critical support pressure decreases and converges over time, indicating that unsaturated transient seepage exerts a significant influence in the short term that stabilizes over the long term. Additionally, sand–silt stratum exhibits lower overall stability and higher sensitivity to groundwater levels and temporal factors compared to silt–clay stratum. Conversely, silt–clay stratum displays a non-monotonic evolution with increasing cover-to-diameter ratios (C/D), reaching a minimum critical support pressure at approximately C/D = 1.1. Regarding heterogeneity, the internal friction angle of the lower layer exerts dominant control over the critical support pressure compared to seepage velocity, while the influence of other strength parameters remains secondary. These findings provide a theoretical basis for the time-dependent design of tunnel face support pressure under excavation drainage conditions. Full article

Early environmental conditions play a critical role in shaping fish physiology and behaviour, with tank colour emerging as a relevant yet often overlooked factor in aquaculture and experimental research. This study investigated how rearing tank colour affects larval performance in the cichlid fish Cichlasoma dimerus. Larvae were reared in white, light-blue, or grey tanks, and survival, growth, pigmentation, sex ratio, skeletal development, and the endocrine responses of somatolactin (Sl) and growth hormone (Gh) were evaluated. Survival was significantly lower in white tanks. Conversely, larvae reared in white tanks reached a higher final body weight, while total length showed a similar but non-significant trend. Gh-immunoreactive cells exhibited significantly larger nuclear areas in larvae reared in white tanks and a tendency toward smaller cytoplasmic areas compared with those from light-blue tanks. Melanophore number did not differ among treatments, whereas larvae from grey tanks showed a higher number of Sl-immunoreactive cells. Sex ratios tended to be female-biased in white tanks. Skeletal development did not differ among tank colours and followed the expected chondrogenesis and ossification sequence. Overall, tank colour influenced multiple aspects of larval development, particularly survival, growth, and endocrine responses, underscoring its relevance in fish rearing and experimental design. Full article

Background: This study evaluates an additive manufacturing (AM) network designed to balance economic performance, lead time, and environmental impact within the healthcare logistics and supply chain. Methods: An integrated framework is proposed that identifies optimal AM facility locations using spatial K-means clustering and optimizes delivery routes through a multi-objective vehicle routing problem with time windows (MOVRPTW). This framework was applied to a case study in Phra Nakhon Si Ayutthaya, Thailand, utilizing hospital geocoordinates, demand profiles, and CO₂ emission factors to evaluate centralized versus decentralized network configurations. Results: Findings demonstrate that hub structures derived from K-means clustering achieve the highest economic efficiency, reducing the AM part cost per unit to 698.51 Baht. In contrast, a fully centralized network resulted in a significantly higher unit cost of 4759.79 Baht, while clustering based on hospital types yielded a unit cost of 959.34 Baht. Quantitative results indicate that the multi-objective approach provides a superior trade-off, achieving lead time requirements while maintaining operational costs and emissions. Conclusions: The results indicate that the proposed framework, particularly through spatial clustering, offers a practical decision-support tool for designing AM networks that achieve a balance between operational efficiency and sustainability objectives in healthcare logistics. Full article

Agricultural industrial parks have been promoted as a key instrument for agricultural modernization, yet causal evidence of their impact on raising rural residents’ income remains limited. This study evaluates the income effects of National Modern Agricultural Industrial Parks (NMAIPs) in China, clarifying the transmission mechanisms and distributional consequences for rural households and the urban–rural income gap. Using county- and household-level panel data (2014–2022), we exploit the staggered rollout of NMAIPs as a quasi-natural experiment and employ a staggered Difference-in-Differences (DID) design with two-way fixed effects, complemented by event-study analysis. Results show that NMAIP establishment raises rural residents’ income by approximately 1.83% on average. Mechanism analysis indicates that this gain operates primarily through employment expansion, technological upgrading, and capital agglomeration. At the household level, NMAIPs significantly increase wage and operating income but have limited effects on property and transfer income, reflecting constraints in rural asset markets. Furthermore, NMAIPs reduce intra-rural inequality and moderate the urban–rural income gap following an inverted U-shaped path (initial widening followed by narrowing), as benefits diffuse through value chains. We conclude that NMAIPs are an effective policy lever for inclusive rural growth, yet their distributive outcomes could be enhanced by supporting reforms in rural factor markets and public service delivery. Full article