Search Results (4,876)

To enhance regional carbon sequestration capacity and achieve carbon neutrality, it is crucial to accurately estimate the net primary productivity (NPP) of vegetation and its response to changes in land use/land cover (LULC). Based on remote sensing data, the study estimated the NPP of Qingdao, a typical coastal city in eastern China, from 1990 to 2020 using the CASA model and examined its spatiotemporal dynamics. The Geographic Detector was used in the study to measure the impact of anthropogenic and natural factors on variations in NPP. Additionally, the Markov–PLUS model was utilized to forecast future LULC patterns and NPP changes for 2030 under three development scenarios: natural development, cropland protection, and ecological protection. The results indicate considerable regional variation and an initial decrease followed by an increase in Qingdao’s NPP. It is distributed in a strip-like pattern from northwest to southeast, with the regions around Jiaozhou Bay showing the lowest levels. The changes in NPP are driven by multiple interacting factors; among these, LULC, DEM, and slope exhibit significant spatiotemporal correlations with NPP, with LULC playing a dominant role in this process. In addition, interaction analysis demonstrated that the synergistic effects between LULC and other factors constituted the principal driving force behind NPP dynamics, and the interactions between the two factors that contribute show bivariate or nonlinear enhancement effects. The ecological protection scenario produces the greatest NPP values among the three scenarios. Optimizing LULC may significantly increase carbon sequestration capability, as evident in the NPP forecast, which is higher than that of 2020 in all scenarios. This study demonstrates that the ability of vegetation to store carbon can be effectively enhanced through land-use optimization informed by remote sensing technologies. The results provide a scientific basis for adjusting LULC policies and conducting carbon-neutral spatial planning in coastal urban areas. Full article

Microelectromechanical systems (MEMS) have a widespread use in several applications such as signal filtering, time referencing, and sensing. This paper explores the nonlinear dynamic behavior of a MEMS resonator using a reduced-order modeling approach. The study focuses on how multi-modal formulation and detuning affect the system’s response under primary resonance. Using the method of multiple scales, amplitude–phase response equations are derived, and time-domain simulations are generated with the Runge–Kutta method. Two mode combinations are examined: the first mode combined with the second mode and the first mode with the third mode for multi-modal influence evaluation. Results indicate that the first mode provides the dominant behavior to MEMS response, while the second and third modes exhibit minimal participation despite the nonlinearities retained in the presented multi-modal model. Additionally, a detuning study reveals that the geometric and forcing nonlinear effects are stronger near resonance and diminish as the system moves away from it. The analysis suggests that the significant features of the response can be captured in the case of primary resonance using only the first mode, which offers an effective modeling approach. From a design perspective, finding that the first mode alone is sufficient means that the essential dynamic behavior of the MEMS resonator can be predicted and controlled by focusing on its first mode of vibration. In practical terms, this greatly allows engineers to optimize geometry, driving voltage, or control parameters to target the first mode natural frequency without accounting for higher modes, which reduces computational cost and design complexity. Full article

This study investigates the influence of loading pattern, analysis level, and nodal connection stiffness on the stability and dynamic behaviour of a low-rise steel dome. Three joint configurations and two loading scenarios, symmetrical and asymmetrical, were analysed. Structural stability was evaluated using linear buckling analysis, second-order analysis, full geometrically nonlinear analysis. Dynamic properties were determined by modal analyses performed with and without the geometric stiffness matrix. The results show that the structural response is governed primarily by the asymmetric distribution of axial forces. For the model with pinned joints, a 68.4% decrease in the critical load multiplier is observed. Modal analysis revealed that asymmetric loading not only reduced the first natural frequency but also fundamentally changed the modal structure. Global vibration modes disappeared, modal mass became distributed over a large number of modes, and the Modal Assurance Criterion remained below 0.11, confirming a qualitative change in the vibration mechanism. In contrast, symmetrical loading caused only minor frequency reductions while largely preserving the mode shapes. The results demonstrate that linear analyses may significantly overestimate the stability and dynamic performance of low-rise steel domes under asymmetric loading. Accurate assessment therefore requires second-order effects, geometric nonlinearity, and geometric stiffness to be considered. Full article

Most existing humanoid robots possess a payload capacity below 10 kg, which is insufficient for practical material transport tasks. A natural engineering solution is to enable humanoid robots to tow wheeled trailers or hand carts, transferring the vertical load to the wheeled carrier while the robot provides only horizontal traction. This approach is mechanically feasible, low-cost, and compatible with existing logistics equipment. However, the control challenges have not been adequately addressed in the literature. The traction force exerted by the towed load acts as a persistent disturbance on the robot’s center of mass (COM), degrading zero-moment point (ZMP) tracking and compromising gait stability. This paper proposes a disturbance-aware preview control framework for humanoid robots towing heavy wheeled loads. First, the measured traction force is incorporated as a feedforward term into the linear inverted pendulum model (LIPM) to compensate for its effect on gait symmetry. Second, a disturbance-aware preview controller is designed that optimally generates COM trajectories under sustained traction forces by incorporating both ZMP reference preview and traction force preview into a unified optimal preview control framework. The method integrates COM dynamics, traction-force closed-loop compensation, and ZMP reference preview into a single analytical optimal preview control framework, with gait-phase scheduling incorporated through the footstep-based reference trajectory. Simulation results demonstrate that the proposed method reduces ZMP tracking error by 13.5% and COM jerk by 37.7% compared to standard preview control, while maintaining robust walking stability under traction forces exceeding about 180 N. Full article

This study examines how Perumal Murugan’s Seasons of the Palm and Pyre represent the relationship between caste, ecology, and psychological suffering through the concept of solastalgia. While solastalgia is often understood in relation to environmental destruction or climate-related loss, this study argues that Murugan’s narratives expand its meaning by showing how ecological distress can also arise from caste-based exclusion, spatial control, and the denial of belonging within one’s own surroundings. In these narratives, rural landscapes are not neutral settings but socially organised environments shaped by labour, hierarchy, surveillance, and everyday forms of violence. Through the experiences of Shorty and Saroja, the study shows how nature functions as a space that both sustains life and regulates access to it. From Dalit psycho-ecological perspectives, the study argues that ecological suffering in Murugan’s narratives is inseparable from the caste structures. The study further suggests that environmental justice in the Indian context must account for caste as a central force shaping ecological experience. Ultimately, Murugan’s narratives highlight that ecological grief is also social grief and that questions of land, place, and belonging are deeply tied to the structures of power, calling for a more inclusive understanding of ecological thought that recognises these entangled realities. Full article

Independently rotating wheelsets (IRWs) are increasingly adopted in low-floor urban rail vehicles because they enable compact bogie layouts and improved curving performance. However, their limited natural self-centering capability can lead to lateral offset from the track centerline, increased flange contact, and degraded lateral guidance performance. This paper presents an LQ-servo-based differential-torque control method for active centering of IRWs using a control-oriented state-space model derived from linearized wheel–rail creep-force relations. Rather than proposing a new control algorithm, this study establishes and experimentally validates an integrated modeling–control–validation framework for differential-torque active centering, providing new quantitative evidence of its effectiveness. The left and right wheel torques are employed as actuation inputs to regulate the lateral displacement of the wheelset, while a conventional proportional–integral–derivative (PID) controller is implemented as a baseline for comparison. The two controllers are evaluated through numerical simulations and validated experimentally using a 1/5-scale IRW roller rig. Compared with the PID controller, the LQ-servo controller achieves faster centering, improved yaw damping, and reduced steady-state lateral offset. In particular, under representative parameter variations, the fixed-gain PID controller loses stability, whereas the LQ-servo controller remains stable and maintains accurate centering, indicating lower sensitivity to the considered parameter variations in the simulation study, while the hardware experiments confirmed real-time implementation in the presence of unmodeled physical effects. These findings support the effectiveness of the proposed modeling and control approach for active centering of independently rotating wheelsets. Full article

Hypersaline semi-enclosed seas impose physiological constraints on marine bivalves by increasing osmotic regulation costs and limiting somatic growth. This study examined life-history variation in natural populations of the pearl oyster Pinctada radiata across contrasting salinity regimes along the eastern and western coasts of Bahrain in the Arabian Gulf. Environmental conditions, shell morphometrics, growth modeling, oocyte abundance, physiological condition indicators, and the production-to-biomass ratio (P:B) were assessed to determine whether high salinity constrains somatic growth while reproductive persistence is maintained. Monthly surveys were conducted from June 2021 to May 2022 at one pearl oyster bed on each coast, comprising 12 surveys per coast. The two coasts formed a salinity gradient, averaging approximately 42‰ in the east and 55‰ in the west. Oysters from the western coast were smaller, with a mean shell height decreasing from 63.12 ± 6.47 mm in the east to 45.88 ± 3.41 mm in the west. The Gompertz model indicated a lower asymptotic shell height in the more saline population. The population-level P:B ratio was 0.23 yr⁻¹ on the eastern coast and 7.46 yr⁻¹ on the western coast. Despite reduced shell size, western oysters maintained strong seasonal oocyte abundance. The higher biomass turnover in the west partly reflected greater oyster density. This pattern is consistent with osmoregulatory costs and constrained shell biomineralization under chronic hypersalinity. Reproductive activity followed a bimodal pattern on both coasts. These findings are consistent with a life-history trade-off in which pearl oysters exposed to chronic salinity stress maintain reproductive activity despite constrained growth. Overall, this study links environmental forcing, growth limitation, population-level biomass turnover, and reproductive activity, providing field-based evidence that chronic hypersalinity constrains somatic growth while reproductive persistence is maintained in a benthic bivalve inhabiting hypersaline coastal systems under climate-related stress. Full article

Constructed wetlands (CWs) are widely used as an ecological technology for wastewater treatment. However, the accumulation of microplastics (MPs) in their substrates may impair long-term performance and threaten the operational sustainability of these nature-based treatment systems. To elucidate the transport behaviour of MPs in wetland substrates, this study developed a numerical model based on the lattice Boltzmann method (LBM) to simulate advection, hydrodynamic dispersion, and reversible first-order adsorption/desorption of MPs in saturated porous media. The model incorporates a salinity-dependent non-linear attachment rate coefficient, which captures the compression of the electrical double layer and the enhanced attachment efficiency with increasing salinity. Pore-scale flow is solved using the LBM with an Ergun-type drag term to represent the resistance of the porous matrix. The model was validated against experimental breakthrough curves from column studies using quartz sand and coastal wetland soils under five salinity levels (0–35 PSU) reported in the literature. Quantitative validation yielded coefficients of determination (R²) ranging from 0.782 to 0.960 (RMSE = 0.024–0.045) for calibration cases and 0.741 to 0.946 (RMSE = 0.027–0.048) for independent validation cases across both substrates, excluding the soil cases at 3.5 and 35 PSU. Here, both observed and simulated effluent concentrations were identically zero, resulting in the statistically forced R² = 1.000 and RMSE = 0, which are mathematical artefacts rather than indicators of predictive performance. The simulations reproduce the observed reduction in peak relative concentration by over 50% in sand and near-complete retention (C/C₀ ≈ 0) in soil at high salinities (3.5 and 35 PSU). Results demonstrate that the model successfully reproduces the differences in MP breakthrough behaviour across different substrate types and salinity levels. By linking salinity-enhanced retention to the risk of irreversible clogging and shortened wetland lifespan, the model provides a predictive tool for evaluating the sustainability of CWs under saline stress. This study offers a scientific basis for optimizing hydraulic management (e.g., flushing strategies) to mitigate microplastic pollution and enhance the long-term sustainability and resilience of constructed wetlands in coastal and saline environments. Full article

Background/Objectives: Tryptophol and tyrosol are prominent secondary metabolites with diverse biological activities. Acetylation has been proposed as a strategy to modify the physicochemical properties of these compounds. Despite the proven neuroprotective and adaptogenic activity of tyrosol, in vivo studies, particularly concerning the anxiolytic effects of its acetylated forms, are currently limited. Materials and Methods: This study aimed to compare the behavioral effects of tryptophol, tryptophol acetate, and tyrosol acetate in mice using the chloral hydrate sleep model, the Open Field Test (OFT), and the Forced Swim Test (FST). Results: In the chloral hydrate sleep model, both tryptophol acetate and tyrosol acetate (100 mg/kg, i.g.) significantly prolonged sleep duration without affecting sleep latency, whereas none of the tested compounds induced sleep after single administration (100 mg/kg, i.p.). In the OFT, tyrosol acetate (100 mg/kg, i.g.) significantly increased exploratory activity, as reflected by increased time spent in the central zone and number/duration of verticalizations, indicating an anxiolytic-like behavioral profile. In the FST, tyrosol acetate (100 mg/kg, i.g.) significantly reduced immobility time, suggesting an effect on behavioral responses to acute inescapable stress. Conclusions: Overall, the tested compounds exhibited distinct behavioral profiles, with tyrosol acetate producing the most consistent behavioral effects across the experimental models. These findings suggest that acetylation modifies the neuropharmacological properties of naturally occurring aromatic alcohols and support further investigation of tyrosol acetate, including studies of its mechanisms of action and evaluation in additional anxiety-specific behavioral models. Full article

Environmental regulation is widely regarded as an institutional driver of corporate green transformation, yet how it operates on firms and for whom remains unsettled. Treating the 2015 entry into force of China’s revised Environmental Protection Law as a quasi-natural experiment, this study estimates a difference-in-differences (DID) model on 38,910 firm-year observations covering 4447 Shanghai and Shenzhen A-share firms over 2010–2024. Corporate green transformation is measured along three dimensions—the length-normalized intensity of green-transformation language in annual reports, green patent output, and green total factor productivity—and combined into a composite index. The regulation raises green-transformation intensity by 0.156 (about 14.8% of the sample mean) and green total factor productivity by 0.0021; pre-reform event-study coefficients are jointly insignificant, no randomized placebo reaches the observed estimate, and the result survives propensity-score matching and province-by-year fixed effects. It is accompanied by falling greenwashing and rising disclosure specificity, indicating that the additional green language is not merely talk. Bootstrap mediation tests support transmission through executive green cognition and through green exploratory, but not exploitative, innovation. Contrary to the received view, the law did not loosen financing constraints; instead, pre-reform financial capacity bounds the response, and firms that were more constrained respond substantially less. Effects are larger for digitally capable, better-governed firms and in more marketized regions, and command-and-control instruments outperform market-based pilots over this window. Full article

The European Pathfinder THOR project envisages the creation of a vascularized fragment of tissue that can be implanted in a patient using regenerated silk fibers as its building blocks. The selection of regenerated silk as the main building block of the scaffold relies heavily on its outstanding biocompatibility in comparison with either other artificial polymeric fibers or even natural silk fibers. Additionally, regenerated fibers produced through the Dynamic Dope Destabilization Spinning (D3S^TM) process are shown to exhibit high mechanical performance as reflected in values of strain at breaking and work to fracture comparable to those of the natural material. It is further shown that these fibers are endowed with the unique property of self-adhesion whereby hydrated fibers attach to one another and may sustain detachment forces of up to a few tens of MPa, a property that facilitates the generation of the scaffold with the fibers as its basic building block. Lastly, regenerated silk fibers are shown to be efficiently decorated with either peptides or small proteins, such as the vascular endothelial growth factor (VEGF), or with antibodies. The performance of both non-functionalized and decorated silk fibers is assessed in two different in vitro biological systems: (1) endothelial cell cultures, and (2) organotypic brain slice cultures. Together, these results support the use of regenerated silk fibers as versatile building blocks for biofunctional tissue scaffolds and provide experimental validation of the tissue engineering strategy established by the THOR project. Full article

Background: Prolonged smartphone use has been proposed to influence postural alignment and pulmonary function; however, continuous relationships among these variables remain uncertain in young adults. Methods: Thirty healthy university students completed assessments of device-recorded average daily smartphone screen time over the preceding seven days, craniovertebral and shoulder-C7 angles during natural standing, forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and positive and negative affect. Eight Spearman correlations were evaluated using 5000-resample bootstrap confidence intervals and Holm adjustment for multiple comparisons. Separate linear regression models examined smartphone screen time as a predictor of FVC and FEV1 after adjustment for biological sex and height. Results: None of the primary correlations was statistically significant after Holm adjustment. The largest estimate was observed between smartphone screen time and FVC (ρ = −0.242, 95% CI −0.540 to 0.101; Holm-adjusted p = 1.000). In adjusted models, smartphone screen time was not significantly associated with FVC (B = −0.054 L per additional hour/day, 95% CI −0.127 to 0.019; Holm-adjusted p = 0.280) or FEV1 (B = −0.027 L per additional hour/day, 95% CI −0.123 to 0.068; Holm-adjusted p = 0.561). Secondary exploratory analyses identified an inverse correlation between shoulder-C7 angle and negative affect and positive correlations between FVC and height and body weight. Conclusions: Statistically significant primary associations among seven-day smartphone screen time, standing postural alignment, and pulmonary function were not detected. These findings do not establish that the variables are independent and should be interpreted cautiously given the small sample and wide confidence intervals. Full article

Caffeine is a promising active for topical pharmaceutical and cosmetic applications; however, its hydrophilic nature can limit passive transport across the stratum corneum and reduce local retention. Although nanoparticle-loaded dissolving microneedles have been explored, few systems combine a hollow porous carrier, a lipid coating, and a polysaccharide matrix within a single controlled-release platform. This study developed thermosensitive dissolving microneedles (DMNs) incorporating caffeine-loaded liposome-coated hollow mesoporous silica nanoparticles (ULp-Caf@HMSNs). Sodium alginate–κ-carrageenan matrices, with and without stearic acid modification, were evaluated for their effects on thermal behavior, mechanical strength, and caffeine release. HMSNs showed a hollow mesoporous structure and high specific surface area, while FTIR supported successful incorporation of the formulation components. Liposome coating increased particle size while maintaining nanoscale dimensions. Hot-stage microscopy showed temperature-dependent structural changes at approximately 33–35 °C, with lower apparent transition temperatures in stearic acid-containing formulations. All DMNs exhibited compression forces comparable to mechanically competent DMNs, with NaAlg–κ-car systems reaching 14.3–15.1 N per array. Free-caffeine DMNs followed non-Fickian release, whereas ULp-Caf@HMSN-containing formulations followed Higuchi diffusion-controlled release and showed slower caffeine release. Stearic acid did not consistently improve release performance. The novelty of this work lies in integrating a hollow silica reservoir, a liposomal coating, and an alginate–κ-carrageenan microneedle matrix within one platform. Overall, the system provides a basis for further evaluation in controlled topical or transdermal caffeine delivery. Full article

In this study, the response characteristics of spaceborne electronic equipment under actual mounting boundary conditions were evaluated, and an equivalent contact stiffness-based modeling technique was proposed to compensate for the limitations of conventional boundary-condition-based analysis. Finite element analyses were performed for three configurations: an initial design, a structure with increased contact area, and a structure with added stiffeners. Random vibration tests were then conducted with accelerometers directly attached to the PCBs and housings under actual mounting conditions, and the results were compared with conventional analysis results. The conventional analysis overpredicted the actual responses for all configurations, showing discrepancies in response magnitude, housing bottom-surface behavior, and natural frequency distribution. These discrepancies were attributed to insufficient representation of the bottom-surface contact effect formed under actual mounting conditions. Therefore, an empirical equation for the equivalent contact stiffness was established by incorporating fastening force, effective contact area ratio, bottom-surface thickness, and effective span length, and implemented using CBUSH-element-based contact modeling. The proposed method improved the correlation between test and analysis results for all three configurations, demonstrating its applicability for reliable response prediction and overdesign reduction at the early design stage. Full article

Background/Objectives: The longevity of tooth-supported overdentures depends on the retentive stability of attachment systems, yet limited evidence exists on the performance of non-metallic CAD-CAM fabricated mini ball attachments. This study aimed to evaluate the retentive force changes and surface wear of CAD-CAM fabricated mini ball attachments made of zirconia, polyetheretherketone (PEEK), and polymethyl methacrylate (PMMA) for tooth-supported overdentures. Methods: Twenty-one mandibular canine replicas received CAD-CAM copings with mini ball attachments (n = 7 per material). Retentive force was measured at baseline and after 90, 270, 540, 1080 and 2160 insertion–removal cycles (simulating 2 years of clinical use). Surface wear was examined under scanning electron microscopy (one specimen per group, preliminary). Data were analyzed using one-way ANOVA, paired t-tests with Bonferroni correction, and mixed repeated-measures ANOVA (Greenhouse–Geisser correction). Effect sizes (partial η², Cohen’s d) were calculated. Based on a priori power analysis 7 specimens per group were decided. Results: All materials showed a significant decline in retention over cycles (p < 0.001, partial η² = 0.90). No significant differences were found among the three materials at any time point (p > 0.05). The material × time interaction was not significant (p = 0.064). Within each material, baseline-to-final reductions were significant (p ≤ 0.009, Cohen’s d > 3.0). Exploratory SEM suggested minimal wear for zirconia, moderate for PEEK, and pronounced surface deterioration for PMMA. Conclusions: Within the limitations of this study, all three CAD-CAM mini ball attachments provided decreasing but measurable retention over simulated use. Zirconia showed numerically the highest final retention, but no statistically significant differences were detected among materials. Clinically, zirconia attachments demonstrated numerically superior final retention with minimal wear, suggesting potential advantages for long-term use; however, the lack of statistically significant differences among materials and the preliminary nature of the wear analysis warrant caution, emphasizing the need for future clinical validation before definitive material recommendations can be made. Full article