Search Results (107)

Early detection of blade structural degradation is critical for wind turbine reliability, as unplanned failures contribute to approximately 25% of operational downtime. Traditional blade condition monitoring methods based on distributed vibration, strain, or acoustic emission sensing often suffer from high hardware complexity and substantial data-processing requirements. Consequently, blade load measurements at the blade root have emerged as a promising and more practical alternative for structural health monitoring. This study introduces a physics-informed virtual sensing framework that combines high-fidelity aeroelastic simulation with machine learning trained exclusively on healthy operational data for blade degradation detection. The proposed method is based on the premise that, under healthy conditions, the relationship between flapwise and edgewise bending moments remains consistent across operating conditions, whereas structural degradation disrupts this coupling and induces measurable deviations from the learned correlation. To implement this concept, OpenFAST simulations of the NREL 5MW reference turbine are conducted under multiple operating conditions with progressively introduced stiffness degradation, forming a comprehensive dataset. A Random Forest model is trained to predict edgewise bending moments from flapwise loads and structural parameters using only healthy-condition data, achieving high predictive accuracy under healthy operating conditions (R² = 0.98; MAPE = 3.67%). Fault detection is performed by analysing residuals between predicted and simulated edgewise bending moments, which increase systematically when degradation is present. The proposed framework achieved an overall classification accuracy of 88.9%, sensitivity of 88.9%, precision of 96.0%, F1-score of 0.923, and an AUC of 0.951 across all degradation levels and operating conditions, while achieving 100% detection of severe (20%) torsional stiffness degradation cases. Notably, degradation reduces absolute blade loads due to aeroelastic twist-to-feather coupling, yet introduces distinctive load asymmetry patterns that enable effective discrimination. The method demonstrates strong generalisation across the investigated wind speed conditions without retraining. By reconstructing unmeasured edgewise loads from readily available flapwise measurements, the proposed approach enables scalable structural health monitoring of existing wind turbine fleets without hardware retrofitting, offering a practical pathway toward physics-guided digital twin development. Full article

In multi-UAV bearing-only active tracking, the estimation and control performance is fundamentally determined by the target-centered bearing geometry, as passive angle-of-arrival measurements provide directional information without direct range information. To overcome this limitation, this paper formulates the problem as prescribed-shell bearing-geometry self-organization, in which the radial sensing scale is regulated to an admissible shell while the angular bearing distribution is actively reshaped on that shell. A shell-compatible moment–volume bearing-enclosure potential is first constructed directly on unit bearing directions, decoupling angular geometry improvement from unsafe range reduction and encoding directed balance, angular isotropy, and noncoplanar enclosure. To realize the resulting direction-space descent via physical UAV motion, a radius-normalized tangential lifting mechanism is derived from bearing-direction kinematics, eliminating radius-dependent angular-rate bias. The nominal radial–tangential command is then executed through a bearing-geometry-preserving ECBF-QP that embeds a predefined-time radial shell-reaching constraint, enforces target standoff, inter-UAV separation, and input constraints, and preserves shell reaching and tangential geometry improvement whenever feasible. Closed-loop analysis establishes shell reaching, practical bearing-geometry descent, safety forward invariance, and signal boundedness. Finally, improved bearing geometry, prescribed-shell convergence, preserved safety margins, reduced disruption from safety filtering, and real-world implementability are demonstrated via simulations, ablation studies, ROS-based validation, and a real-world flight experiment, which provide a promising approach for multi-UAV bearing-only active tracking. Full article

Post-conflict reconstruction concentrates institutional fragility, supply-chain disruption, and weak regulatory enforcement at the moment when long-term resilience trajectories are being set. Myanmar’s housing sector, operating under prolonged civil conflict and post-earthquake reconstruction pressure, exemplifies these conditions. This research adapts Singapore’s Buildable Design Appraisal System (BDAS) and Constructability Appraisal System (CAS) to Myanmar’s post-conflict housing context and translates the empirical findings into a Knowledge-Based Decision Support System (KBDSS). An integrated framework combining Value Chain Analysis (VCA), the Technology Acceptance Model (TAM), and Scott’s Institutional Framework (IF) underpins the study. A questionnaire survey (n = 139) of Myanmar building professionals is analysed using Partial Least Squares Structural Equation Modelling and Necessary Condition Analysis. The model explains 57.9% of the variance in framework adaptation; competitive advantage, perceived usefulness, perceived ease of use, and the post-conflict/disaster context emerge as both sufficient and necessary conditions, while regulative support dominates among the three institutional pillars. These findings underpin the inference logic of a prototype KBDSS for resilient housing reconstruction. This research contributes empirical evidence on operationalising urban resilience under institutional fragility in the Global South. Full article

Allergic asthma is among the type 2-driven chronic inflammatory allergic diseases. Osteoimmunological findings indicate that shared systemic immune mediators and persistent inflammation can disrupt skeletal homeostasis and promote bone fragility. Treatment commonly includes inhaled corticosteroids like fluticasone propionate (FP) to suppress inflammation, with anti-immunoglobulin E (anti-IgE) biologics added to interrupt the IgE-mediated allergic cascade. TNF-α inhibitors (anti-TNF) are also being studied for their impact on inflammatory pathways. However, their capacity to preserve bone mechanical/mineral integrity in allergic airway inflammation (AAI) remains unclear. This study compared the efficacy of anti-TNF, FP, and anti-IgE monotherapies and an FP/anti-IgE combination in mitigating AAI-induced deficits in bone mechanical/mineral integrity in an ovalbumin (OVA)-induced chronic murine AAI model. Fifty-six male BALB/c mice (8–10 weeks old; 22–24 g) were randomly assigned to control, AAI (OVA-sensitized/challenged), and five treatment cohorts: FP (2000 μg), low-/high-dose anti-IgE (aIgE-L/aIgE-H; 100/200 μg), anti-TNF (aTNF; 6.25 mg/kg-bw), and FP/aIgE-H combination. Following an 8-week protocol, three-point bending and inductively coupled plasma-mass spectrometry (ICP-MS) were used to assess bone mechanical properties and physicochemical characteristics of the mineral phase (calcium (Ca) and phosphorus (P) levels; stoichiometric Ca/P ratio), respectively. Analyses showed that aIgE-L and FP monotherapies failed to mitigate AAI-induced bone changes. aTNF and aIgE-H monotherapies provided comparable protection of cross-sectional properties, rigidity, energy-to-fracture, elastic modulus, and yield/ultimate moments; however, aIgE-H was more efficacious in preserving Ca and P levels and the stoichiometric Ca/P ratio. The FP/aIgE-H combination demonstrated the greatest efficacy in preventing mechanical deterioration and preserving mineral integrity, suggesting it as the optimal strategy for maintaining skeletal health in the management of type 2-driven AAI. Full article

Background: Understanding the benefits of psychedelic-assisted therapy (PAT) will require scientific attention to the causal interaction between the therapeutic context and process. Measuring what actually happens during PAT in large-scale studies will be an essential component of this work. Objective: We aim to develop and preliminarily evaluate the feasibility and reliability of a direct observation coding system for narrations of awe experiences during PAT, one hypothesized therapeutic mechanism. Methods: We analyzed 32 PAT clinical trial encounter recordings involving eight participants from a Phase 2 clinical trial study of psilocybin-assisted therapy in advanced cancer. Using a conceptually grounded structured codebook, two human coders independently identified start and stop times for moments exhibiting definitional characteristics of awe narration, including expressions of vastness, need for accommodation and ineffability. We used coder agreement and degree of confidence to refine the coding system. Results: During 16,760 total minutes of video, coders collectively recorded 246 moments of awe narration. Of those moments, 42% (104/246) were identified by one coder and 58% (142/246) by two coders. Coders felt substantially more confident in their judgments about a moment of awe when vastness was present compared to when vastness was absent (OR: 4.3; 95% CI: 2.4, 7.8). Iterative refinement of the coding system led to accommodation being operationalized as two distinct components: an initial cognitive disruption followed by variable engagement in the process of accommodation. Conclusions: Awe narration is directly observable using explicit definitional criteria. This work provides the empirical foundation for scalable coding systems of awe narration during PAT. Full article

Background: In an era characterized by rapid technological disruption and vocational uncertainty, Career Adaptability (CA) has emerged as a critical meta-competency for university students transitioning into the workforce. While the importance of CA is well-documented, the internal mechanisms that foster it remain under-explored. This research adopts a resource-based perspective to investigate how Mindfulness—a state of non-judgmental present-moment awareness—acts as a catalyst for career readiness. Specifically, this study examines a dual-mediation model, proposing that Mindfulness enhances Emotional Intelligence (EI) and Psychological Capital (PsyCap) (comprising hope, efficacy, resilience, and optimism), which in turn bolsters an individual’s capacity to adapt to changing career landscapes. By integrating these four constructs, the study provides a comprehensive framework for understanding how “being present” (Mindfulness) translates into “being prepared” (Career Adaptability) through the cultivation of emotional and psychological resources. Methods: The study collected data from 705 final-year students at Wollo University (male = 399 and female = 306). The study employed several well-established instruments: the Compound Psychological Capital Scale (CPC), the Five Facet Mindfulness Questionnaire (FFMQ), the Wong and Law Emotional Intelligence Scale (WLIES), and the Career Adapt-Abilities Scale (CAAS). These instruments were rigorously evaluated for their psychometric applicability within the Ethiopian context. Results: PLS-SEM analysis revealed: (a) direct and positive influences of mindfulness, PsyCap, and EI on career adaptability; (b) partial and positive mediation effects of PsyCap and EI in the mindfulness-career adaptability link; (c) a serial mediation effect of mindfulness through PsyCap and EI; and (d) the proposed model explained a substantial amount of variance in university students’ career adaptability. Conclusions: Despite its strengths, the study acknowledged certain limitations and discussed potential implications for enhancing career adaptability, highlighting the benefits of cultivating mindfulness. Full article

Architected polymer composites use spatially organized phases to achieve targeted property combinations. Shape forming elements (SFEs) are modular coextrusion die inserts that impose internal architectures by reshaping multiple melt streams. This study evaluates three SFE designs (Jacks, I-Beam, and Barn Door) that position a liquid crystalline polymer (LCP) and an amorphous polyamide (APA) in distinct core–shell configurations. Polymer clay prototyping and ANSYS Polyflow simulations were used to screen flow behavior, followed by extrusion at two puller speeds and characterization via optical microscopy and tensile testing. Microscopy revealed that abrupt area transitions and viscosity contrast disrupt encapsulation and distort designed features. Regression analysis showed that LCP content governs stiffness and strength, while higher puller speed enhances reinforcement through molecular orientation. Cross sectional geometries were quantified using interfacial perimeter, moments of inertia, and polar dispersion ratios, and correlated to tensile performance. Increased interfacial length reduced modulus, strength, and ductility. Modulus improved with LCP orientation and confinement, strength increased when LCP was placed at vertical extremities, and elongation was maximized by horizontally distributing LCP within a thick APA shell. These results demonstrate that SFEs enable tunable tradeoffs between stiffness, strength, and ductility. Full article

Recently, the coprecession of both the accretion disk and the jet formed following the tidal disruption event associated with the optical transient AT2020afhd, driven by a supermassive black hole of almost ten million solar masses, were independently measured in both the X and radio bands, respectively, showing a periodicity of nearly 20 days over about 300 days. An analytical model of the general relativistic gravitomagnetic Lense-Thirring precession of the effective orbit of a fictitious test particle revolving about a spinning primary can explain the observed precessional features. It yields allowed regions in the system’s parameter space which, as far as the hole’s dimensionless spin parameter is concerned, are essentially in agreement with those obtained in the literature with general relativistic magnetohydrodynamic simulations. The present analytical approach can be extended to include the precession due to the hole’s quadrupole mass moment as well. It breaks the degeneracy in the allowed regions occurring for negative and positive values of the spin parameter when only the Lense-Thirring effect is considered. The best estimate for the hole’s mass yields the range 0.185–0.215 for the dimensionless spin parameter. Using the same strategy with the gravitomagnetic frequency for an extended disk of finite size with a parameterized power-law mass density yields to distinct, generally non-overlapping allowed regions for each value of the power-law index adopted. Some of the assumptions on which this work is based are critically examined. Full article

Several successive crises during the first three decades of the third millennium created the premises for a world that, after expanding international relations, entered a new reality of slowbalization or deglobalization, shaping new development paradigms for national economies. In this context, where economic activity remains highly sensitive to energy market disruptions and strategic resource constraints, nations seek new opportunities to reduce their foreign dependencies through energy diversification and a green transition. Nations are seeking strategies to leverage their advantages and moderate their weaknesses. This research evaluates the relationship between energy-related features and economic growth in a complex context, describing dependency on foreign markets. Furthermore, the study discusses the effects of a selection of variables describing the green transition (energy import dependency, energy diversification, and the share of renewable energy) on economic growth. The data covers the period between 1995 and 2024 for 25 European countries. The study uses cross-sectionally ARD (CS-ARDL) for the main empirical analysis and augmented mean group (AMG) to check the robustness of the main results. Furthermore, the method of moments quantile regression (MMQR) is employed to capture the impact more precisely across various stages of countries’ development. The findings suggest a direct relationship between employment and renewable energy adoption across all quantiles. Moreover, the negative coefficient for the energy dependency in the first quantile documents an increased sensitivity of less developed economies to energy market uncertainties. Full article

This study investigates the influence of out-of-plane beam skew on the cyclic performance of column-tree steel moment connections. Utilizing validated finite element (FE) models against experimental data, the cyclic responses of various configurations were evaluated under the AISC cyclic loading protocol up to a story drift ratio of 0.05 rad. Skew angles of 0°, 10°, 20°, and 30° were examined across three representative beam depths. The results demonstrate that all configurations satisfy the AISC 341 acceptance criteria for Special Moment Frames (SMFs), maintaining at least 80% of the plastic moment capacity (0.8 M_p) up to a 0.04 rad story drift ratio. However, the introduction of beam skew resulted in a gradual reduction in energy dissipation capacity, with the total dissipated energy decreasing by 2.9–8.9% at a 30° skew. Notably, the inelastic energy component was more sensitive to the skew than the frictional components, exhibiting a maximum reduction of 15.4%. While out-of-plane skew disrupted the symmetry of stress triaxiality and plastic strain at the beam-to-column interface, the overall fracture susceptibility was not significantly exacerbated up to 30°. Furthermore, column twisting remained within a negligible range (below 0.5°), and its impact on global stability was limited. Despite the general stability, a premature bolted splice failure was observed in deep beam configurations at a 30° skew during the 0.05 rad drift cycles. Based on these findings, it is concluded that column-tree connections with an out-of-plane skew up to 30° are viable; however, a design limit of 20° is recommended for deep beam configurations to ensure structural integrity under extreme cyclic demands. Full article

Classic machine learning and regime identification methods applied to financial time series lack theoretical guarantees and exhibit systematic failure modes: heavy-tails invalidate moment-based geometry, rendering distances and centroids dominated by extremes or unstable; jumps violate smoothness, destabilizing local regressions, kernel methods, and gradient-based learning; and non-stationarity disrupts neighborhood relations, so distances in classical feature spaces no longer reflect meaningful proximity. To address these challenges, we propose a topology-based machine-learning framework grounded on probabilistic reconstruction of state-space geometry, which replaces moment- and smoothness-dependent representations with deformation-stable summaries of state-space geometry, preserving neighborhoods, adjacency, and topology. The finite-sample validity of homeomorphic state-space reconstruction, required for topology-based machine learning, is assessed through numerical studies on synthetic data with heavy tails, jumps, and known ground-truth regimes. Further diagnostics of local invertibility and bounded geometric distortion quantify when embedding windows are consistent with local diffeomorphic behavior, enabling metric-sensitive, geometry-aware learning. Clustering of Hilbert-space summaries accurately recovers underlying market tail-risk regimes with robust results across selected filtrations. Temporal, feature-space, and cluster-label null tests confirm that topology-based clustering captures genuine topological structure rather than noise or artifacts, and encodes temporal dependencies at local, mesoscopic, and network levels associated with market regimes. Full article

The increasing adoption of high-aspect-ratio wings to improve aerodynamic efficiency introduces significant structural flexibility, necessitating the integration of aeroelastic considerations into the earliest design stages. While critical, existing frameworks often lack the multi-fidelity modeling capabilities and automated workflows required to bridge conceptual design and high-fidelity verification. This paper presents the Flexible Aero-Structural Toolbox (FAST), a modular framework supporting both beam and shell structural modeling and integrated with MSC NASTRAN for industry-standard aeroelastic simulation. The toolbox’s capabilities are demonstrated through modal, flutter, and static aeroelastic analyses across three distinct configurations: the P-FLEX UAV, the Ventus sailplane, and an A320-like transport aircraft, including its hydrogen-powered derivative. Results show that FAST accurately captures the aeroelastic characteristics of high-aspect-ratio wings and effectively predicts loads for large-scale flexible airframes. Notably, analysis of the hydrogen configuration reveals a significant 25% increase in wing bending moments for the “dry” wing condition compared to standard kerosene configurations. Furthermore, the tool’s ability to model unconventional mass distributions, such as cryogenic fuel tanks, highlights its adaptability for disruptive aircraft technologies. The study concludes that FAST provides a versatile, physics-based decision-making environment that significantly improves efficiency in the aeroelastic analysis process without compromising simulation fidelity. Full article

Sudden disruptions can destabilize everyday routines and open the door to pro-environmental behavioral change. This paper examines whether exogenous Moments of Change (MoC) with different temporal profiles—an acute nationwide power outage in Spain and the prolonged COVID-19 disruption—reshape employees’ workplace pro-environmental behavior (PEB) by weakening the relationship between habits and PEB. Study 1 surveyed 226 Spanish office workers 38 days after a brief blackout, while Study 2 followed 135 employees in Spain and the Netherlands longitudinally across the COVID-19 period. We found that, while reported PEB increased after both disruptions, the short-term blackout was insufficient to weaken the relationship between habits and behavior significantly, or to strengthen individual and organizational drivers of behavior. In contrast, the more prolonged COVID-19 disruption significantly weakened the influence of habits on PEB and strengthened the relationship between perceived corporate environmental responsibility and behavior. These findings suggest that the duration of a disruption is a critical factor. Specifically, brief shocks may elicit specific new behaviors; only prolonged disruptions appear sufficient to break established habits and enhance the influence of organizational factors on employees’ pro-environmental actions. Full article

Heliostats constitute essential elements within concentrating solar power (CSP), where their structure, load profiles, and operational environment render wind loads a critical factor in their design considerations, as these loads directly impact the cost of energy generation. The aerodynamics significantly influence wind-induced effects, resulting in considerable variability in wind loads among different heliostat geometries. This study utilizes the Computational Fluid Dynamics (CFD) methodology to systematically examine the aerodynamic behavior of an isolated pentagonal heliostat. Employing the Unsteady Reynolds-Averaged Navier–Stokes (URANS) equations with an atmospheric boundary layer inlet condition, the investigation focuses on the flow field and wind load characteristics at four representative pitch angles: 0° (stow position), 30°, 60°, and 90°. Findings indicate that the pitch angle exerts a decisive impact on flow separation patterns. Specifically, as the elevation angle decreases, the flow regime shifts from being predominantly influenced by the mirror surface to being governed by the support structure, mediated through an interactive coupling between these components. At the 60° operational pitch angle, the pentagonal heliostat’s distinctive corner geometry induces an asymmetric vortex configuration—characterized by a smaller vortex at the top and a larger one at the bottom—thereby disrupting the conventional vortex distribution observed in symmetric heliostat designs. A further analysis of wind load characteristics indicates that, compared to a quadrilateral heliostat, the pentagonal mirror exhibits a significantly lower Elevation Moment Coefficient, despite a slight increase in the normal force coefficient. This reduction is attributed to a balancing mechanism: the “vortex structure asymmetry” creates an upper-large–lower-small distribution of absolute negative pressure on the support surface, while the “stagnation point position” shift with elevation angle produces an upper-small–lower-large distribution of absolute positive pressure on the reflector. The interaction between these opposing trends minimizes the net pressure differential across the mirror height, thereby contributing to superior overall aerodynamic performance. The reduction in the elevation moment coefficient contributes to enhanced structural wind resistance, thereby improving the overall energy efficiency and economic viability of concentrating solar power. Full article

This article examines how the early Pentecostal movement in Kerala created a liminal space for Dalits and women—groups historically marginalized by caste and patriarchy—to exercise spiritual agency and contest social hierarchies. Grounded in a Spirit-centered theology that emphasized charismatic openness and the democratization of spiritual gifts, early Pentecostalism disrupted conventional modes of authority and belonging. Drawing on Victor Turner’s theory of liminality, this study interprets this early period as a threshold moment wherein new forms of identity and communal life briefly emerged. While Pentecostalism offered a radically inclusive grammar of participation, its emancipatory potential was ultimately constrained by institutionalization and the reassertion of social norms. Nonetheless, within this fragile and contested space, Dalits and women found opportunities for voice, leadership, and embodied transformation rarely available in other ecclesial traditions. By recovering the theological and historical significance of this liminal journey, this article contributes to broader conversations on decolonial ecclesiology, Spirit-led resistance, and the ongoing tension between charisma and structure in Pentecostal movements. Full article