Search Results (32,343)

Conventional Fiber-Reinforced Polymer (FRP) materials may exhibit certain performance uncertainties in harsh environments, limiting their reliability for structural strengthening. To address this, Basalt Fiber-Reinforced Polymer (BFRP) plates fabricated with silicate-modified epoxy resin are proposed for the flexural strengthening of reinforced concrete (RC) beams. The research aims to evaluate their short-term strengthening performance and establish a reliable calculation method for flexural capacity. Four-point bending tests were conducted to investigate the effects of BFRP plate thickness and end anchorage configuration on failure modes, flexural capacity, and ductility. Finite element simulations incorporating interfacial bond–slip behavior reproduced typical debonding failures, followed by a comprehensive parametric analysis. Based on the experimental and numerical results, a modified BFRP plate strain formula at debonding was proposed to establish a calculation method for the flexural capacity of BFRP-strengthened beams governed by debonding failure. The results indicate that beams without end anchorage were prone to interfacial debonding, where increasing the plate thickness from 0.5 mm to 2 mm raised the flexural capacity gain from 4.5% to 15% but intensified the ductility reduction from 42.9% to 64.9%. Conversely, applying mechanical anchorage improved the ductility index by over 20% compared to unanchored counterparts. The adopted FRP–concrete bond–slip constitutive model accurately characterizes interfacial debonding behavior, and the proposed flexural capacity model demonstrates high accuracy with overall deviations within 5%. It can be concluded that the novel BFRP plates exhibit strengthening behavior comparable to existing FRP systems. Effective end anchorage further enhances flexural capacity and prevents brittle failure. The proposed debonding strain formula for the novel BFRP system offers a reliable basis for capturing the critical onset of interfacial failure. Building upon this, the developed flexural capacity model provides a reliable theoretical basis for the design and assessment of RC beams strengthened with the novel BFRP plates. Full article

Stimuli-responsive hydrogels, also referred to as “smart” hydrogels, have emerged as versatile platforms for a wide range of biological and biomedical applications owing to their tunable physical, chemical, and biocompatible properties. Their adaptability arises from both their ability to undergo reversible swelling–deswelling and volume phase transitions in response to specific physicochemical or biological stimuli and the diversity of synthesis strategies that enable precise tailoring of material properties to meet distinct biomedical demands. Recent advances have led to the development of novel hydrogel designs with improved swelling–deswelling behavior, enhanced stimulus sensitivity, and superior biocompatibility, thereby expanding their applicability in complex biological environments. Despite this progress, challenges such as precise control over hydrogel size and relatively slow response kinetics remain critical barriers to broader biomedical and clinical translation. Addressing these limitations requires strategies, including reducing hydrogel particle dimensions to accelerate response rates and engineering heterogeneous or highly porous gel architectures to increase functional surface area. This review provides a comprehensive classification of stimuli-responsive hydrogels based on their physical properties and response mechanisms, and summarizes recent innovations in their design, synthesis, and biomedical applications. Furthermore, it discusses emerging approaches to enhance the clinical applicability of smart hydrogels in controlled drug release, targeted gene delivery, biosensor development, and tissue engineering. Overall, continued optimization of swelling–deswelling characteristics and material design will be essential to fully realize the potential of stimuli-responsive hydrogels in precision medicine and advanced therapeutic applications. Full article

Background: Cubital Tunnel Syndrome (CuTS) is the second-most common compressive neuropathy of the upper limb, traditionally associated with prolonged elbow flexion, trauma, or anatomical constraints. With the widespread adoption of smartphones, sustained upper-limb postures have emerged as potential novel risk factors for ulnar nerve compression. This retrospective study aimed to investigate the potential correlation between smartphone use patterns and the development of CuTS. Methods: A retrospective observational study was conducted on 100 subjects recruited between 2021 and 2024, including 50 patients with EMG-confirmed CuTS who underwent surgical decompression and 50 matched controls without clinical or electrophysiological evidence of ulnar neuropathy. Demographic variables, daily smartphone use (h/day), predominant activity type, and habitual posture during device handling were collected through clinical records and questionnaires. Group comparisons were performed using t-tests and Chi-square analyses, with significance set at p < 0.05. Results: Daily smartphone use was higher in the CuTS group compared with controls (4.94 ± 1.8 vs. 4.04 ± 1.5 h/day), although the difference did not reach statistical significance (p = 0.0716). Posture during device use showed a significant association with CuTS: 82% of affected patients reported using smartphones with the elbow flexed, compared with 56% of controls, whereas supportive postures were less frequent among CuTS patients (16% vs. 38%) (p = 0.019). No significant differences were found between groups regarding smartphone activity type (p = 0.858). Conclusions: Smartphone use may contribute to ulnar nerve compression primarily through ergonomically disadvantageous postures, particularly sustained elbow flexion, rather than total usage time. These findings highlight a modifiable behavioral risk factor relevant to the rising prevalence of CuTS in the digital era. Increased clinical attention to device-handling habits and public-health strategies promoting ergonomic posture may support CuTS prevention. Prospective and biomechanically informed studies are warranted to further elucidate causal mechanisms. Unmeasured confounders (e.g., occupational and sleep-related elbow flexion) may influence these associations. Full article

Ground vortex formation beneath aeroengine intakes during near-ground operations represents an energy-related aerodynamic issue, as it degrades inlet flow quality, induces pressure distortion, and reduces the effective utilization of incoming kinetic energy. This study investigates the unsteady characteristics of ground vortex flow under headwind conditions and its influence on foreign object ingestion (FOI) in an aeroengine intake. Three-dimensional unsteady Reynolds-averaged Navier–Stokes (URANS) simulations coupled with a Lagrangian Discrete Phase Model (DPM) are employed to resolve the interaction between intake-induced vortices and dispersed particles near the ground. The results indicate that the ground vortex rapidly develops into a quasi-periodic state, generating significant unsteady total pressure distortion at the intake face, with peak fluctuations reaching approximately 10% of the mean value. This flow non-uniformity reflects a deterioration of inlet energy distribution and is detrimental to downstream compression efficiency. Particle ingestion behavior is strongly dependent on particle density and diameter. Low-density and small particles are more readily entrained into the vortex core and ingested, whereas particles with higher density or larger size exhibit increased inertia and reduced sensitivity to vortex-induced energy transport. The ingestion region is biased toward the lower portion of the intake, consistent with the vortex core location. These findings provide insight into vortex-induced energy distortion and FOI mechanisms, offering guidance for improving aeroengine intake design and energy-efficient operation during near-ground conditions. Full article

Despite the centrality of scalar implicature (SI) in pragmatic development, the neurocognitive trajectory of SI processing in Mandarin-speaking children remains underexplored, with existing frameworks inadequately accounting for developmental constraints and cross-linguistic variation. This ERP study maps the neurocognitive trajectory of scalar implicature (SI) processing in Mandarin preschoolers (N = 49). Behavioral accuracy improved with age (p < 0.001) but was not modulated by contextual felicity. Neural dynamics revealed developmental shifts: 4-year-olds exhibited heightened P200 amplitudes in infelicitous contexts, indicating attentional overloading. Differences in P200 amplitude between younger and older children indexed developmental shifts in attentional allocation. The N400 showed contextual sensitivity, whereas the Late Positive Component (LPC) showed only marginal context effects, suggesting protracted inferential adjustments. We propose the Cognitive-Dynamic Relevance Model (CDRM), challenging existing frameworks by integrating gradual recalibration mechanisms with resource constraints. Mandarin children demonstrate delayed SI maturation, attributable to reduced SI frequency in child-directed speech and quantifier ambiguity. Findings underscore cross-linguistic variation in pragmatic development, with neurocognitive markers preceding behavioral mastery. Full article

High-entropy amorphous materials are attracting increasing attention due to their excellent corrosion resistance and radiation tolerance in nuclear environments. In this study, novel Al₂Cr₁₆Fe₅₀V₂₀Ti₁₂ high-entropy alloy (HEA) coatings with thicknesses of 900 nm and 1400 nm were synthesized via magnetron sputtering and systematically evaluated for their structural, electrochemical, and mechanical performance. X-ray diffraction confirmed the amorphous nature of the coatings, while scanning electron microscopy revealed a denser, defect-free, and more uniform morphology in the thicker coating. Electrochemical testing in a 3.5 wt.% NaCl solution demonstrated a tenfold reduction in corrosion current density and nearly a twofold increase in charge transfer resistance for the 1400 nm coating, attributed to its improved passive film stability. Finite element modeling validated the experimental load–displacement behavior and revealed well-confined and uniformly distributed stress and strain fields within the coating. These findings establish the 1400 nm Al₂Cr₁₆Fe₅₀V₂₀Ti₁₂ coating as a promising candidate for protective applications in chloride-rich and radiation-intense nuclear systems. Full article

Waste lignin from the hydrolysis of lignocellulosic materials is an abundant but underused by-product of the pulp and biorefinery industries. Phenolic compounds derived from lignin, rich in aromatic structures, show strong antioxidant potential and can be applied in polymer stabilization, food, and medical fields. This study evaluated the radical-scavenging activity of phenolic fractions obtained from alkaline-treated waste lignin against DPPH● and ABTS•⁺, using Trolox as a reference. Both spectrophotometric and electrochemical techniques were employed, providing deeper insight into the underlying mechanisms. Depending on the assay, the phenolic extracts demonstrated substantial radical-scavenging capacity, in some cases matching or surpassing that of Trolox. This behavior was linked to electron/proton transfer pathways, radical reactivity, and solubility effects. The combined use of multiple antioxidant tests offered a comprehensive characterization of the bioactivity of lignin-derived phenolics and supports their potential as sustainable sources of antioxidant compounds within a circular economy framework. Furthermore, the study examined how toluene-extracted phenolics affect the thermo-oxidative stability of model polyurethane films. Incorporating small amounts (1%, 3%, 5%) into the polymer matrix showed that a 1% loading provides the most effective stabilization. At higher concentrations, however, additional oxidative processes seem to be activated, as indicated by FTIR measurements and thermogravimetric analysis. Full article

In this work, sustainable aluminum-modified orange peels functionalized with graphene oxide (OP-Al-GO) were synthesized and evaluated for the removal of Methylene Violet (MV) and Reactive Red 120 (RR120) from aqueous solutions. Adsorption performance was systematically investigated in single-dye systems, binary dye mixtures, and real textile wastewater samples, and compared with that of orange peels (OP), orange peel–aluminum composite (OP-Al), and graphene oxide (GO). pH_pzc analysis clarified the surface charge of the adsorbent, while SEM and FTIR showed that the incorporation of aluminum and GO increased roughness and functional groups appearance, enhancing dye adsorption and confirming successful interactions. The OP-Al-GO composites exhibited improved removal efficiency for both dyes (64.8% for RR120 and 96.2% for MV) at pH 3.0. The presence of aluminum improved structural stability and surface charge regulation, while graphene oxide contributed to multiple adsorption mechanisms, including electrostatic attraction and π–π interactions. The adsorption kinetics were found to follow a pseudo-second-order (PSO) kinetic model for RR120 and an intraparticle-diffusion model (IPD) for MV, while isotherm analysis revealed a Langmuir behavior for MV and a Freundlich behavior for RR120. Langmuir maximum adsorption capacities were 298.7 and 10.8 mg/g for MV and RR120, respectively. High removal efficiency was maintained in binary dye mixtures, with OP-Al-GO achieving 96.9% removal of MV and 85.7% of RR120. Furthermore, the proposed adsorbent was tested on real wastewater samples, and the results highlight that the proposed adsorbents are promising, low-cost, and environmentally sustainable for textile wastewater treatment. Full article

Carbon dioxide (CO₂) emissions resulting from natural gas flaring are significant contributors to atmospheric greenhouse gases, posing a substantial risk to the Earth’s climate by exacerbating global warming. As a response, both the oil industry and government authorities are actively exploring cost-effective strategies to address this issue through carbon capture, utilization, and storage (CCUS), as well as reducing natural gas flaring and CO₂ leaks in the oil fields to mitigate the adverse consequences of greenhouse gas emissions. This study presents a numerical investigation of CO₂ utilization for enhanced oil recovery (EOR) and associated CO₂ retention in unconventional reservoirs, using the Bakken Formation as a representative case. A compositional reservoir model is developed to simulate CO₂ Huff-n-Puff (HnP) processes in a fractured horizontal well. The model incorporates dual-porosity and dual-permeability formulations, fluid–rock interactions, and an equation-of-state-based compositional framework to capture multiphase flow behavior. Key operational parameters, including reservoir pressure, injection rate, injection duration, and CO₂ molecular diffusion, are systematically evaluated to assess their impact on oil recovery and CO₂ retention. The results show that lower bottom-hole pressures enhance oil recovery through increased drawdown, while operating pressures near the minimum miscibility pressure (MMP) improve CO₂ solubility and overall retention. Extended injection durations and higher diffusion coefficients increase CO₂ dissolution in the oil phase but exhibit diminishing marginal benefits beyond an optimal injection time. The study quantifies residual and solubility trapping mechanisms during the operational timeframe of CO₂-EOR and provides mechanistic insights into optimizing CO₂-HnP performance in tight formations. The proposed framework establishes a technical basis for integrating CO₂-EOR with emission mitigation strategies in unconventional reservoirs. Full article

As China’s electric vehicle (EV) market transitions from rapid growth to high-quality development, competition among brands is shifting from purely technological aspects to more holistic expressions involving spatial design and brand positioning. This study investigates the coupling mechanism between spatial aesthetics and brand positioning and its influence on consumer purchase intention. Drawing on Gibson’s theory of spatial aesthetics and the Technology Acceptance Model (TAM), we develop a theoretical framework that integrates perceived usefulness and perceived ease of use of spatial aesthetics with brand cognition. Empirical analysis is conducted using coupling coordination degree modeling and multiple regression, based on 1576 valid questionnaires collected from 4S dealerships of nine major EV brands in China. The results indicate that spatial aesthetic elements—such as environmental visual flow, invariance, and affordance—positively affect consumers’ perceptions of technology and brand recognition. Furthermore, the degree of coupling between spatial aesthetics and brand positioning perceptions significantly enhances purchase intention, particularly among consumers of safety-oriented and luxury EV models. These findings confirm the synergistic effect of spatial experience and brand strategy in shaping consumer behavior, enriching the theoretical understanding of EV consumer psychology and offering practical guidance for strategic decision-making in product design and brand communication. Full article

Crowd mass disasters occur over a relatively short time, and rescue operations in disasters, such as earthquakes, are challenging because of people’s behavior, type, or location. Therefore, it is essential to devise means and methods to manage such problems to minimize the consequences as much as possible. During disasters, rescue operations should be conducted in a timely conducted to save people’s lives. Otherwise, losses and consequences are severe, and if there are no proper rescuing operation models, the situation worsens, and the consequences are devastating. In particular, the allocation and coordination of limited rescue resources have a critical impact on response times and the number of lives saved. This paper aims to develop an Agent-Based Simulation (ABS) model for rescuing operations in crowd-mass disasters with six main intelligent agents. The proposed model explicitly represents the interactions among victims, rescuers, command-and-control entities, transportation assets, road networks, and affected infrastructure within a GIS-based urban environment. The developed model is based on an enhanced approach to improve rescue agents’ tasks allocation operations that enable modeling and simulation to make critical decisions for people to be rescued in a crowded mass disaster. Our task-allocation mechanism incorporates dynamic accessibility of roads, time-dependent rescue capacity, and context-aware prioritization of victims. Three related task-allocation strategies from the literature are used as baselines under identical scenarios, and performance is compared in terms of average rescue time and number of rescued victims. Results show that the proposed model achieves more efficient and robust rescue operations in most simulated experiments. Full article

Parallel iterative schemes are widely used for the simultaneous computation of all distinct roots of nonlinear equations in scientific computing and engineering. While high-order parallel methods can provide substantial acceleration, their practical performance is often dominated by the choice of internal real-valued parameters introduced by correction/acceleration mechanisms, which may strongly affect convergence speed and numerical robustness. Classical parameter-selection strategies—based on analytical sufficient conditions, trial-and-error experimentation, or qualitative dynamical diagnostics (basins of attraction, bifurcation-style inspection, and parameter planes)—are typically problem-dependent, expensive to scale, and difficult to automate reproducibly. In this work, we propose a data-driven framework for systematic parameter optimization based on finite-time contractivity profiling. The approach uses k-nearest neighbors (kNN) micro-series analysis to estimate a proxy profile of the largest Lyapunov exponent (LLE) along the iteration index, summarizing the transient contraction/expansion behavior of the solver trajectories. Two profile-based scores, the minimum score $S_{min}$ and the moment score $S_{\mathrm{mom}}$, are introduced to rank candidate parameter pairs and to construct stability landscapes over $(\alpha ,\beta )$ grids. As a testbed, we apply the framework to a bi-parametric two-step parallel Weierstrass-type scheme and demonstrate that the learned parameter regions yield faster and more reliable convergence than generic or manually tuned choices. Extensive numerical experiments show that the proposed profiling-based optimization consistently improves convergence rate and robustness across the considered nonlinear test problems, providing a scalable and reproducible alternative to heuristic and dynamical-system-based tuning. Full article

With the rapid development of intensive animal husbandry, the widespread use of livestock and poultry manure as organic fertilizers has become a major anthropogenic source of antibiotic contamination in agricultural soils. Antibiotics, classified as “emerging contaminants” owing to their persistence, biological activity, and potential ecotoxicity, undergo environmental fate processes such as adsorption–desorption, migration, transformation, and degradation upon entering orchard soils, with their behaviors regulated by multiple factors, including soil physicochemical properties, microbial communities, and climatic conditions. Antibiotics not only alter the structure and diversity of soil microbial communities, inhibit soil enzyme activities, and interfere with the cycling of carbon, nitrogen, and phosphorus nutrients but also induce the generation and dissemination of antibiotic resistance genes (ARGs) and affect the growth and reproduction of soil animals, triggering cascading effects on ecological processes. Moreover, antibiotics can be absorbed by fruit tree roots and transported to aboveground organs via the xylem or phloem. By interfering with photosynthesis, disrupting antioxidant systems, and affecting hormone balance, they inhibit the growth and development of fruit trees, thereby altering the appearance, nutritional, and flavor qualities of fruits. Furthermore, antibiotic residues and ARGs in fruits pose potential risks to food safety. This paper thoroughly analyzes the pollution levels, environmental interactions, and disposition of antibiotics in orchard soils, focusing on the mechanisms that influence their impact on soil microecology and biochemical processes. It also explores the absorption, transport, and accumulation patterns of antibiotics in fruit trees, as well as their effects on tree physiology, growth, fruit quality, and safety. Finally, the current research gaps and prospects are identified, aiming to provide a theoretical basis for ecological risk assessment, scientific prevention and control of antibiotic contamination in orchard ecosystems, and safeguarding of agricultural product safety. Full article

This paper investigates the dynamics of a permanent magnet synchronous motor (PMSM) and controls its chaotic speed behavior using the synergetic control technique (SCT). The model includes electrical dynamics in the dq frame and mechanical speed dynamics, with a scalar parameter $\gamma$ capturing cross-coupling effects. The equilibrium structure and local stability properties of the PMSM are analyzed. For zero input voltages and zero load torque, the system exhibits a pitchfork-type bifurcation in the electrical–mechanical equilibrium as $\gamma$ crosses a critical value. Explicit expressions are derived for all equilibria, and their stability is characterized using eigenvalue analysis and the Routh–Hurwitz criterion, and a secondary loss of stability via a Hopf-type mechanism is identified. The case of nonzero input voltages with zero load torque is also discussed. Numerical simulations confirm the analytical results and highlight the parameter regions that admit stable operation. Bifurcation diagrams show the different PMSM behaviors as the parameter $\gamma$ varies. For a certain interval of $\gamma$, the PMSM speed undergoes chaotic oscillations. The SCT is introduced to control the chaos. Macro variables are chosen to design the SCT. The derived SCT is implemented to eliminate the chaotic speed. The controller provides good performance in suppressing the chaos. The controller is tested under sudden reference speed change where the controller gets the new reference speed accurately. It is also evaluated under sudden and sinusoidal load torque variations. Full article

The increasing demand for sustainable construction materials has intensified research on supplementary cementitious materials capable of reducing Portland cement consumption and associated CO₂ emissions. In this context, porcelain polishing residue (PPR), a fine ceramic waste generated by the tile industry, presents potential for valorization in cement-based composites. This study investigates the use of PPR as a supplementary cementitious material in self-compacting concrete (SCC), focusing on its pozzolanic activity and its influence on fresh, physical, and mechanical properties. Pozzolanic behavior was evaluated using strength-based indices with lime and Portland cement, as well as the modified Chapelle method. SCC mixtures were produced with partial replacement of cement by PPR at different levels and assessed in terms of self-compactability, compressive strength, elastic modulus, water absorption, and void index. The results showed that, although PPR did not meet strength-based pozzolanicity criteria at early ages, it exhibited significant calcium hydroxide consumption, indicating latent pozzolanic potential. Fresh-state properties were preserved in all mixtures, and an optimal replacement level of 20% resulted in improved long-term mechanical performance, reduced void content, and enhanced matrix compactness. These findings demonstrate that PPR can be effectively used as a functional supplementary cementitious material in SCC, contributing to more sustainable and eco-efficient concrete production. Full article