Search Results (122)

Despite its rich cultural heritage, the Yellow River Basin (YRB) faces challenges of ecological fragility and unbalanced development that constrain residents’ welfare improvement. Cultural–tourism integration (CTI)—aimed at creating employment, optimizing industrial structure, and improving public services—is increasingly promoted as a pathway to enhance people’s livelihood and well-being (PLW). Grounded in industrial integration theory and welfare economics, this study examined the impact effects, transmission mechanisms, and spatial spillovers of CTI on PLW. Panel data from 75 prefecture-level cities in the YRB, spanning 2011 to 2023, were utilized, and multi-dimensional indices were constructed for both CTI and PLW. Impact effects, mediating mechanisms, and spatial spillovers were examined through kernel density estimation, a dynamic system generalized-method-of-moments (SYS-GMM) model, mediation analysis, and a spatial Durbin model (SDM). The results showed that CTI and PLW both improved over time and displayed a spatial pattern of “midstream and downstream leading, upstream lagging”. CTI significantly promoted PLW, after controlling for dynamics and endogeneity (SYS-GMM coefficient = 0.130, p < 0.01). Industrial structure upgrading acted as a positive mediator, whereas digital infrastructure exhibited a short-term suppressing (negative mediating) effect, implying a phased mismatch between CTI investment priorities and digital input. Spatial estimates further indicated that CTI generated positive spillovers, improving PLW in neighboring cities, in addition to local gains. These findings suggest that basin-wide coordination and better alignment between CTI projects and digital infrastructure are essential for inclusive and sustainable well-being improvements, supporting regional progress toward the Sustainable Development Goals. Full article

The long-term flexural performance of steel-concrete composite beams after creep is influenced by multiple factors such as the degree of shear connection, cross-sectional form, and boundary conditions. The engineering community has an ambiguous understanding of the coupling effects of these factors. To address this issue, this paper conducts systematic experimental research: six simply supported beams (three box-shaped, three I-shaped) and four continuous beams (two box-shaped, two I-shaped) were designed with three degrees of shear connection (0.57, 1.08, 1.53). These beams first underwent simulated creep tests (24 °C, 80% relative humidity, 10 kN load, 180 days), followed by monotonic bending tests. The results indicate: (1) A high degree of shear connection (1.53) reduces creep deflection by 15–20% compared to partial connection (0.57) and delays the initiation of interface slip to 30% of the ultimate load; (2) Box sections exhibit 10–15% lower creep deflection than I-sections, though both experience 40–60% stiffness reduction after creep; (3) Continuous beams show a 25% improvement in crack resistance in the negative moment region and a 50% increase in flexural capacity at mid-span compared to simply supported beams; (4) After creep, the elastic modulus of concrete decreases by 40–60% (inversely related to the degree of shear connection), with fully connected specimens retaining 55–61% of their strength, while partially connected specimens retain only 43–49%. This study quantifies the degradation patterns of concrete performance, clarifies the influence mechanisms of key structural factors, and provides theoretical and experimental support for the long-term performance design of composite beams. Shear connection design is crucial for mitigating creep effects. Full article

This study uses a dataset of conventional banks from 2010 to 2022 to investigate the moderating effect of board characteristics (BC) on the relationship between corporate social responsibility (CSR) and bank stability in the MENA region. Bank stability is measured using the Z-ROA index, which captures a bank’s ability to withstand financial shocks. The study addresses endogeneity and heterogeneity concerns using the system generalized method of moments (SGMM), with diagnostic tests confirming the validity of instruments and the absence of second-order autocorrelation. Three main conclusions are presented. First, CSR has a major detrimental impact on bank stability, indicating that when poorly managed or misaligned with strategic objectives, CSR initiatives may weaken financial resilience. Second, board attributes such as independence, diversity, and experience have a positive impact on bank stability, highlighting the importance of sound governance in ensuring prudent financial management. Third, the interaction between CSR and board characteristics exerts a positive and significant influence on bank stability, suggesting that well-structured boards can enhance the strategic value of CSR initiatives. As a robustness check, the study re-estimates the model using non-performing loans (NPLs) as an alternative measure of bank stability. The results remain consistent with the baseline findings, confirming the robustness and credibility of the conclusions. CSR continues to show a positive association with NPLs, while board characteristics and their interaction with CSR maintain negative and significant effects. These findings reinforce that effective board governance can transform CSR practices into stability-enhancing strategies. For policymakers and banking executives seeking to integrate sustainability into governance frameworks, the results underscore the crucial role of corporate governance in translating CSR efforts into tangible stability outcomes. The study calls for greater regulatory focus on board structures to maximize the stability benefits of CSR in the banking sector, contributing to the growing body of research on CSR and financial stability in developing economies. Full article

This study investigated a strengthening strategy for reinforced concrete (RC) T-beams in the negative-moment region using polymer cement mortar (PCM) systems. Monotonic loading tests were conducted on beams retrofitted with PCM, incorporating steel reinforcements of either 13 mm or 16 mm in diameter. The flexural performance of the strengthened specimens was assessed under three-point bending, with a focus on load–deflection behavior, crack patterns, and failure modes. Key structural parameters governing the structural response were analyzed. The findings indicated that incorporating PCM markedly improved the flexural capacity of RC T-beams, with increases in the ultimate load of 55% and 99% for the two reinforcement configurations. Although the beam strengthened with 16 mm steel bars exhibited reduced ductility, its energy absorption was 29% higher compared to its 13 mm counterpart. A three-dimensional nonlinear finite element model was also developed in ABAQUS 6.14, and its predictions closely matched the experimental observations. Full article

This study presented a comprehensive finite element (FE) investigation into the flexural behavior of RC T-beams strengthened in the negative moment region using near-surface mounted (NSM) carbon-fiber-reinforced polymers (CFRP) rods. A three-dimensional nonlinear FE model was developed and validated against experimental data, achieving close agreement with normalized mean square error values as low as 0.006 and experimental-to-numerical ratios ranging from 0.95 to 1.04. The validated model was then employed to conduct a systematic parametric analysis considering CFRP rod diameter, concrete compressive strength, longitudinal reinforcement ratio, and FRP material type. The results showed that increasing CFRP diameter from 6 to 10 mm enhanced ultimate load by up to 47.51% and improved stiffness by 1.48 times. Higher concrete compressive strength contributed to stiffness gains exceeding 50.00%, although this improvement was accompanied by reductions in ductility. Beams with reinforcement ratios up to 2.90% achieved peak loads of 309.61 kN, but ductility declined. Comparison among FRP materials indicated that CFRP and AFRP offered superior strength and stiffness, whereas BFRP provided a more balanced combination of strength and deformation capacity. Full article

The method addresses the challenges of non-steady conditions at an early age by combining wavelet filtering and empirical mode decomposition (EMD) to separate strain components arising from shrinkage, expansive agent compensation, temperature variations, construction disturbances, and live loads. The approach incorporates construction logs as external constraints to ensure accurate correspondence between signal features and physical events. Scientifically, this study addresses the fundamental problem of identifying and quantifying multi-source strain components under transient and non-steady construction conditions, which remains a major challenge in the field of structural monitoring. Field monitoring was conducted on typical cast-in-place concrete components: a full-width bridge deck in the negative moment region. The results show that both structural types exhibit a distinct shrinkage–recovery process at an early age but differ in amplitude distribution, recovery rate, and restraint characteristics. During the construction procedure stage, the cast-in-place segment in the negative moment region was sensitive to prestressing and adjacent segment construction. Under variable loads, the former showed higher live load sensitivity, while the latter exhibited more pronounced temperature-driven responses. Total strain decomposition revealed that temperature and dead load were the primary long-term components in the structure, with differing proportional contributions. Representative strain variations observed in the field ranged from 10 to 50 µε during early-age shrinkage–expansion cycles to 80–100 µε reductions during prestressing operations, quantitatively illustrating the evolution characteristics captured by the proposed method. This approach demonstrates the method’s capability to reveal transient stress mechanisms that conventional steady-state analyses cannot capture, providing a reliable basis for strain monitoring, disturbance identification, and performance evaluation during construction, as well as for long-term prediction and optimization of operation–maintenance strategies. Full article

This study examines the effect of environmental innovation on emission performance and the moderating role of board gender diversity among firms in the Middle East and North Africa (MENA) region. Using a panel dataset of 2319 firm-year observations from 13 countries between 2013 and 2024, the analysis applies fixed-effects regression and robustness checks using the Generalized Method of Moments (GMM). The findings show that environmental innovation significantly improves emissions performance, confirming its strategic role in achieving sustainability goals. Board gender diversity has a positive direct impact on emissions outcomes, suggesting that diverse boards enhance sustainability-oriented governance. However, the interaction term has a negative and significant effect, indicating that gender diversity, while beneficial overall, can weaken the link between environmental innovation and emission performance, possibly because of complex decision-making processes. This study contributes theoretically by extending the Resource-Based View and Porter Hypothesis to an under-researched context, while emphasizing the need for governance mechanisms that leverage diversity without slowing innovation implementation. Future research should incorporate qualitative insights and examine other governance factors to deepen our understanding of how board composition influences sustainability strategies. Full article

As aviation operations extend into complex natural environments, dust particles present significant challenges to flight stability and safety, particularly in dust-prone regions like southern Xinjiang. This study employs high-fidelity computational fluid dynamics (CFD) simulations, combined with the SST turbulence model and the Lagrangian discrete phase model, to analyze the aerodynamic response of the NACA 0012 airfoil at varying wind speeds (5, 15, and 30 m/s) and angles of attack (3°, 8°, and 12°). The results indicate that, at low speeds and moderate to high angles of attack, dust particles reduce lift by over 70%, primarily due to boundary layer instability, weakened suction-side pressure, and premature flow separation. Higher wind speeds slightly delay flow separation, but cannot counteract the disturbances caused by the particles. At higher angles of attack, drag increases by more than 60%, driven by wake expansion, shear dissipation, and delayed pressure recovery. Pitching moment frequently reverses from negative to positive, reflecting a forward shift in the aerodynamic center and a loss of pitching stability. An increase in dust concentration amplifies these effects, leading to earlier moment reversal and more abrupt stall behavior. These findings underscore the urgent need to improve aircraft design, control, and safety strategies for operations in dusty environments. Full article

This study investigates the impact of financial performance and corporate governance mechanisms on environmental, social, and governance (ESG) disclosure in Saudi Arabia, a country undergoing significant institutional transformation under Saudi Vision 2030 and Tadawul’s 2021 ESG reporting reforms. While ESG research has gained traction globally, studies in emerging economies, particularly in the Gulf region, remain limited. This paper addresses this gap by examining whether profitability, measured by return on assets (ROA), and board size influence ESG disclosure. This study analyzes 260 firm-year observations of Saudi non-financial listed companies from 2009 to 2023. Using multiple regression analysis, including ordinary least squares (OLS), fixed effects (FE), and generalized method of moments (GMM), the analysis controls for endogeneity and ensures robust results. Findings indicate that board size had a negative and statistically significant relationship with ESG disclosure. The robustness tests confirm the inverse relationship between board size and ESG. ROA showed no correlation with ESG disclosure in the main findings; however, robustness tests revealed a negative and significant correlation. This study is the first to explore these impacts post Tadawul’s 2021 ESG guidelines. It also offers novel insights into ESG practices aligned with Saudi Vision 2030. This study contributes to the literature by situating ESG disclosure within the Saudi context, highlighting the unique role of governance dynamics in shaping sustainability practices in emerging markets. The results carry practical implications for policymakers, regulators, and corporate boards by recommending stronger governance frameworks, such as board-level ESG committees, executive compensation linked to ESG, and sector-specific disclosure standards. Full article

Prestressed concrete structures are facing serviceability challenges due to rising live loads, material degradation, and seismic demands. Retrofitting with carbon fiber-reinforced polymer (CFRP) offers a cost-effective alternative to full replacement. This study presents a finite element (FE) modeling framework to simulate the seismic performance of prestressed concrete T-beams retrofitted in the negative moment region using near-surface-mounted (NSM) CFRP rods and sheets. The model incorporates nonlinear material behavior and cohesive interaction at the CFRP–concrete interface and is validated against experimental benchmarks, with ultimate load prediction errors of 4.41% for RC T-beams, 0.49% for prestressed I-beams, and 1.30% for prestressed slabs. A parametric investigation was conducted to examine the influence of CFRP embedment depth and initial prestressing level under three seismic conditions. The results showed that fully embedded CFRP rods consistently improved the beams’ ultimate load capacity, with gains of up to 10.84%, 16.84%, and 14.91% under cyclic loading, near-fault ground motion, and far-field ground motion, respectively. Half-embedded CFRP rods also prove effective and offer comparable improvements where full-depth installation is impractical. The cyclic load–displacement histories, the time–load histories under near-fault and far-field excitations, stiffness degradation, and damage contour analysis further confirm that the synergy between full-depth CFRP retrofitting and optimized prestressing enhances structural resilience and energy dissipation under seismic excitation. Full article

The circular economy (CE) aims to reduce environmental degradation by ensuring the continuous use of materials and energy resources, aligning with the decarbonization agenda. However, despite the rising acceptance of CE concepts, the economic and managerial aspects remain underexplored in policy and practice. Therefore, this study seeks to bridge the knowledge–practice gap by studying how technology-driven innovation, renewable energy, and energy efficiency interact with CE principles to advance sustainable environmental connections in a detailed manner. The economic analysis of this study was conducted using two base and moderation models, utilizing global data from 78 developing and developed countries, and applying Fixed Effect, Random Effect, and Generalized Method of Moments estimates. The samples were selected based on data availability from internationally recognized databases from 2010 to 2021. The key findings suggest that technology-driven innovation and renewable energy reduce carbon emissions, whereas gross domestic product (GDP) growth and energy efficiency show no standalone positive effects. Notably, moderation effects reveal that the integration of technology with GDP promotes sustainability outcomes, but energy efficiency and renewable energy interact negatively with emissions, a contradictory result warranting further policy investigation. CE-driven innovation promotes decarbonization by striking a balance between environmental preservation, economic expansion, and technology uptake. This study emphasizes region-specific techniques and offers policy insights for combining the CE with natural capital and green GDP. It increases the knowledge of how circular business models powered by technology support sustainable growth and the shift to a circular economy. Full article

Under the pressure of global low-carbon transformation, the sustainable development initiative of the United Nations has gradually become an essential orientation of corporate Environmental, Social, and Governance (ESG) performance. Based on the integrated theoretical framework of sustainable development finance, this work explores the relationships among corporate ESG performance, its financing constraints in China, and its influencing mechanism, as well as the role played by green innovation in this relationship. Using a comprehensive panel dataset of 1038 A-share listed companies from 2013 to 2023, totaling 11,418 observations, we find that corporate ESG performance and financing constraints exhibit a significant negative relationship, indicating that strong corporate ESG performance can effectively alleviate corporate financing constraints. To address endogeneity concerns, we employ a systematic generalized method of moments (GMM) and a two-stage least squares regression using lagged instrumental variables. The results of the mechanism test show that ESG performance mitigates financing constraints by reducing perceived financial risks, improving information transparency, and increasing access to government green subsidies. Furthermore, moderating effect analysis reveals that green innovation strengthens the mitigating effect of corporate ESG performance on financing constraints in this process, based on SDG 9. Heterogeneity analysis reveals that this mitigating effect of corporate ESG performance on financing constraints is more pronounced for firms in China’s economically advanced eastern region, for companies facing harder budget constraints, and in the period following the implementation of the stringent new Environmental Protection Law. Distinguishing between genuine and symbolic corporate actions, we provide evidence that only substantive ESG improvements, as opposed to “greenwashing,” are rewarded by capital providers. The findings provide insights for the formulation of government policies and corporate sustainability strategies in emerging markets. Full article

This paper presents the design of a nonlinear Multi-Input Multi-Output (MIMO) Feedback Linearization Controller (FLC) for the longitudinal dynamics of a fixed-wing UAV. The proposed approach employs dynamic extension to achieve Feedback Linearization in a fourth-order longitudinal model, offering a more compact alternative to existing high-order formulations. The controller ensures the accurate tracking of predefined airspeed and flight path angle references, that is, the control of the magnitude and direction of the velocity vector using engine thrust and pitch moment as control inputs. Additionally, this study determines the region of attraction in which the controller design remains well-defined. This analysis provides critical insights for selecting feasible airspeed and flight path angle references, helping to prevent conditions that can lead to instability or undesirable behaviors, such as the need for negative thrust. Numerical simulations validate the effectiveness of the proposed method in handling the aircraft’s nonlinear dynamics and maintaining stable flight performance. Full article

Energy security has emerged as a critical concern amid intensifying climate risks and surging energy demand driven by economic growth. This study examines the impact of climate risk on energy security by constructing a panel dataset covering 30 Chinese provinces from 2006 to 2022. Using the instrumental variable generalized method of moments (IV-GMM) model, we estimate the marginal impact of climate risk on energy security and further investigate its asymmetric, direct, and indirect relationships via panel quantile regression and mediation analysis. Our key findings are as follows: (1) Climate risk exerts a significant negative impact on energy security, indicating an inverse relationship. (2) The effect of climate risk is asymmetric, with a stronger adverse impact in regions with lower levels of energy security. (3) Climate risk undermines energy security by reducing energy accessibility, affordability, sustainability, and technological efficiency. (4) Energy transition and energy efficiency serve as critical mediators in the relationship between climate risk and energy security, offering insights into potential mitigation pathways. Unlike previous studies that primarily examine energy security in isolation or focus on single dimensions, this research integrates a multidimensional indicator system and advanced econometric techniques to uncover both direct and mediated pathways, thereby filling a key gap in understanding the climate–energy nexus at the provincial level in China. Based on these findings, we propose targeted policy recommendations to enhance energy security by improving climate resilience, accelerating the deployment of renewable energy, and optimizing energy infrastructure investments. Full article

Although it is generally accepted that economic freedom stimulates economic growth, its effects in transitional economies are still up for debate. More empirical research is needed to examine the long-term effects of economic freedom on growth in the Western Balkans, a region characterised by uneven reform trajectories, fiscal pressures, and institutional fragility. This study examines the effects of seven fundamental factors on real GDP per capita growth (annual percentage change) in six Western Balkan nations between 2013 and 2023. These factors include property rights, government spending, government integrity, business freedom, monetary freedom, trade openness, and education spending. Importantly, in order to better capture macroeconomic constraints, it takes into account two fiscal burden indicators: the public debt and the government budget deficit. A triangulated analytical framework is used: Random Forest regression identifies non-linear patterns and ranks the importance of variables; Bayesian Vector Autoregression (VAR) models dynamic interactions and inertia; and the Generalised Method of Moments (GMM) handles endogeneity and reveals causal relationships. The GMM results show that while government integrity (β = −0.0820, p = 0.0206), government spending (β = −0.0066, p = 0.0312), and public debt (β = −0.0172, p = 0.0456) have negative effects on growth, property rights (β = 0.0367, p = 0.0208), monetary freedom (β = 0.0413, p = 0.0221), and the government budget deficit (β = 0.0498, p = 0.0371) have positive and significant effects on growth. Although the majority of economic freedom indicators are statistically insignificant, Bayesian VAR confirms strong growth persistence (GDP(−1) = 0.7169, SE = 0.0373). On the other hand, the Random Forest model identifies the most significant variables as property rights (3.72), public debt (5.88), business freedom (4.65), and government spending (IncNodePurity = 9.80). These results show that the growth effects of economic freedom depend on the context and are mediated by the state of the economy. Market liberalisation and legal certainty promote growth, but their advantages could be offset by inadequate budgetary restraint and difficulties with transitional governance. A hybrid policy approach, one that blends strategic market reforms with improved institutional quality, prudent debt management, and efficient public spending, is necessary for the region to achieve sustainable development. Full article