Search Results (602)

Glacial lake outburst floods (GLOFs) are high-impact hazards in mountain regions, yet many events remain poorly documented because field access is limited and lake evolution can occur on sub-weekly time scales. Here, we used high spatiotemporal resolution PlanetScope imagery (3 m) to quantify the seasonal evolution and abrupt drainage of a moraine-dammed glacial lake in August 2025 in northern Pakistan. Historical lake dynamics were reconstructed using PlanetScope (2016–2024) imagery and multi-decadal Landsat observations (1992–2018). Climatic conditions were evaluated using ERA5-Land temperature data, and seasonal snow dynamics were characterized using MODIS and PlanetScope-based snow cover analyses. Multi-decadal satellite imagery indicates that lake formation in this catchment was historically intermittent, with no evidence of abrupt drainage before 2025, highlighting the anomalous nature of the event. PlanetScope observations show steady lake expansion throughout summer 2025, reaching a maximum area of 0.052 km² prior to the GLOF on August 22. Pre- and post-event imagery reveals no discernible landslide or impact trigger. Instead, the observations are most consistent with a failure mechanism driven by meltwater-driven lake growth and overtopping or erosion of the moraine dam. The 2025 summer season (June to September) was characterized by exceptionally warm conditions and unprecedented early snow depletion relative to the 2000–2024 baseline, suggesting a strong climatic and cryospheric contribution to the outburst. These results demonstrate the value of integrating dense time series of satellite observations and climatic data for capturing glacial-lake life cycles and diagnosing likely controls on outburst initiation. The study highlights the critical role of high-frequency satellite remote sensing for improving GLOF monitoring and early-warning capabilities in data-scarce mountain environments. Full article

An experimental investigation was conducted to examine the resistance to sulfate attack and chloride ion diffusion of concrete incorporating multiple industrial wastes (MIWC), including limestone powder (LP), tailings sand, and silica fume (SF). The degradation mechanisms of the MIWC under coupled sulfate wet‒dry cycles and chloride ion penetration are systematically revealed. Nine concrete mixtures were designed with variable water-to-binder (w/b) ratios, LP contents, SF dosages, and tailings sand/machine-made sand ratios. The results indicate that reducing the w/b ratio significantly enhances resistance to sulfate attack and chloride penetration. A moderate LP dosage optimizes pore structure and improves long-term sulfate resistance, whereas SF effectively refines the pore matrix and reduces the chloride diffusion coefficient. The coupled action of chloride and sulfate accelerates early-stage pore filling by corrosion products but promotes later-stage cracking because of expansive erosion products. A modified sulfate damage model and a multifactor coupled chloride diffusion model are established, which consider damage evolution, chloride binding, and time-dependent diffusivity. The predicted service life of the MIWC under marine exposure is in reasonable agreement with the experimental trends. This work provides a theoretical basis for durable design and industrial waste utilization in marine concrete structures. Full article

HIV-1 protease (PR) is an essential enzyme in the viral life cycle and a primary target of antiretroviral therapies, particularly protease inhibitors (PIs). Understanding the dynamics of viral evolution and the factors governing the emergence or loss of resistance-associated mutations is critical for improving PI efficacy and managing drug resistance in HIV/AIDS treatment. In this study, we investigated the impact of three natural HIV-1 polymorphisms (T12A, L63Q, and H69N), whose prevalence varies depending on treatment status and viral subtype, on the structural stability and conformational dynamics of PR using molecular dynamics (MD) simulations. Three independent 500 ns MD simulations were performed for the native protease and each mutant system. Although none of the mutations disrupts the overall structural integrity of HIV-1 PR, they induce mutation-specific alterations in flexibility and residue interactions. In particular, T12A and H69N exhibit increased structural deviations, especially in the flap regions, along with enhanced conformational fluctuations. In contrast, the L63Q mutation shows a slight reduction in flap flexibility compared to both the native protease and the other mutants. Consistently, the fraction of time spent in open-flap conformations is higher for T12A and H69N and lower for L63Q relative to the native system. Moreover, mutations in the Fulcrum (T12A) and Cantilever (L63Q and H69N) regions do not disrupt the long-range network of correlated motions observed in the native protease, both inter- and intra-monomer, but instead increase the extent of correlated and anti-correlated motions in other regions of PR. Full article

Under long-term cyclic loading, the cumulative plastic deformation of unsaturated sandy subgrade is a key control factor for the pavement’s service performance. However, its evolution mechanism and quantitative characterization still lack a universal model. In this study, based on the GDS dynamic triaxial system, a series of cyclic tests were conducted under different conditions: matric suction from 0 to 90 kPa, net confining pressure from 30 to 120 kPa, dynamic stress amplitude from 60 to 240 kPa, and compaction degrees of 87–96%, reaching a total of 10,000 cycles. The results reveal that the permanent deformation of unsaturated sandy subgrade material evolves through three stages: fast, slow, and stable. The deformation is exponentially negatively correlated with matric suction, net confining pressure, and compaction degree, and exponentially positively correlated with dynamic stress amplitude. A coupling prediction model was developed by embedding matric suction and compaction degree factors into the Karg model. This model incorporates net confining pressure, dynamic stress amplitude, matric suction, and compaction degree. By using a normalized master curve method, the permanent deformation curves under different working conditions were compressed into a unique dimensionless function. The parameters have clear physical significance and allow for a unified description across stress, suction, state, and soil types. Experimental data, along with data from the literature, were used to validate the model, showing prediction errors of less than 10% and R² > 0.95. The model provides a simple, high-precision, and transferable theoretical tool for long-service-life subgrade deformation control. Full article

Optimized dispatch of microgrids is crucial for improving the economic performance and long-term sustainability of modern low-carbon power systems. In particular, accurate economic dispatch modeling for battery energy storage systems (BESSs) is essential for properly evaluating the operational benefits and lifetime costs of microgrids. However, when both battery cycle aging and calendar aging are considered, the resulting scheduling model becomes highly nonlinear, high-dimensional, non-convex, and multimodal, which poses substantial challenges to conventional optimization methods. To alleviate the above problem, a symmetry-guided multi-strategy differential hybrid slime mold algorithm (MDHSMA) is introduced for the day-ahead economic dispatch of microgrids under a refined battery degradation framework. First, a chaotic bimodal mirrored Latin hypercube sampling strategy is designed to exploit symmetry during population initialization, thereby enhancing diversity and improving structured coverage of the search space. Second, a history-driven adaptive differential evolution mechanism is integrated to balance global exploration and local exploitation more effectively during the iterative search process. Third, a state-aware stagnation handling framework is incorporated to maintain population vitality and further improve convergence accuracy and robustness. MDHSMA is evaluated against 12 state-of-the-art optimizers on the CEC2017 and CEC2022 benchmark suites and two representative engineering optimization problems to verify its overall performance. In addition, it is applied to a microgrid case study with refined BESS degradation modeling. The results show that MDHSMA achieves the lowest comprehensive operating cost by effectively coordinating electricity arbitrage and battery life consumption. Moreover, it guides the energy storage system toward shallow charge–-discharge patterns, thereby mitigating accelerated degradation caused by excessive cycling. These results confirm the effectiveness and practical value of the proposed method for sustainable microgrid dispatch in complex nonconvex optimization scenarios. Full article

This study systematically reviews the evolution of Qatar’s tourism sector to evaluate the historical barriers impeding its development and the strategic initiatives deployed to enhance destination competitiveness. The research’s primary aim is to provide a theory-driven longitudinal analysis of Qatar’s tourism evolution, identifying systemic barriers and adaptive responses required for long-term sustainability. Grounded in the theoretical synthesis of Butler’s Tourism Area Life Cycle (TALC) and Dynamic Capability Theory (DCT), the research employs a systematic literature review (SLR) guided by the PRISMA framework, screening 4846 records to analyze 24 final studies. The findings reveal five primary structural and perceptual barriers: a price–value mismatch (luxury perception), regional political instability, cultural and regulatory constraints, environmental vulnerabilities, and gaps in tourist infrastructure. Utilizing DCT, the results demonstrate how the destination exhibited adaptive governance by sensing these barriers and seizing strategic opportunities—such as mega-event hosting and visa reforms—to partially transform its tourism system. These insights highlight that while created resources drive initial visibility, sustaining long-term competitiveness and sustainable growth relies on continuous institutional reconfiguration and socio-cultural alignment. Full article

Fatigue cracking and stiffness degradation remain critical challenges for concrete flexural members used in bridge decks, crane beams, pavements, and other structures subjected to repeated loading. Layered beams that combine normal concrete in the compression zone with steel-fiber concrete in the tension zone offer a promising route to reduce self-weight while retaining crack resistance and ductility. However, the coupled influence of layer depth and fiber dosage on the flexural fatigue response of such members is still insufficiently quantified for reliable engineering design. Unlike previous studies that mainly focused on homogeneous SFRC members, UHPC-based members, or layered beams under static loading, the present study addresses a more practice-oriented but less explored problem, namely the flexural-fatigue behavior of cast-in-place layered beams composed of normal concrete in compression and steel-fiber concrete in tension. More importantly, the study does not examine fiber effect or layer geometry separately, but quantifies within one unified framework how lower-layer height ratio and fiber dosage jointly govern fatigue life, stiffness retention, crack development, and failure transition. A calibrated nonlinear finite-element model with damage-plasticity constitutive laws and cycle-block degradation was further established to reproduce the experiments and to conduct a broader parametric study. The results show that no horizontal crack formed at the cast interface and that the strain-deflection response preserved the typical three-stage fatigue evolution. Increasing either the steel-fiber volume fraction from 0.8% to 1.6% or the lower-layer height ratio from 0.5 to 0.7 markedly prolonged fatigue life and improved crack control. A practical fatigue-life relation, a stiffness-degradation law, and a numerical response surface are proposed, indicating that a height ratio of 0.6–0.7 combined with a fiber dosage of 1.2%–1.6% provides the best balance between fatigue durability, stiffness retention, and failure ductility. Full article

The tensile and low-cycle fatigue properties of a Fe-Ni-based GH1059 superalloy were investigated at room temperature (RT, about 25 °C) in air and at 550 °C in high vacuum. The tensile curve at 550 °C indicated that dynamic strain aging in the material at high temperature. The fatigue life and stress-strain behavior were analyzed, and fatigue parameters were obtained. The fatigue life decreased with increasing temperature. The cyclic deformation behaviors were composed of three stages at RT: cyclic hardening, gradual cyclic softening, and final rapid rupture. The cyclic deformation behaviors at 550 °C were different: the second stage of specimen at 0.4% strain amplitude was cyclic hardening and the second stage of specimen at 0.9% strain amplitude was stress saturation. The difference is because of dynamic strain aging at high temperature. Based on the fatigue data, the changes of friction stress were analyzed, and the results reflected microstructural evolution associated with fatigue behavior. The microstructural evolution during fatigue process was observed using a scanning electron microscope and a transmission electron microscope. The changes in dislocation densities accounted for the effects of temperature and strain amplitude on the fatigue behavior of GH1059. Full article

This paper presents a comprehensive life-cycle analysis of distribution transformers, based on realized measurements of the increased power losses as a result of their long-term service under real-world conditions. The study is based on aggregated measured data from extensive fleets of oil-immersed distribution transformers characterized by diverse designs, manufacturing vintages, and service lives. The evolution of no-load losses and short-circuit losses is analyzed as a function of operational duration, structural characteristics, and the specific technologies employed for windings and magnetic core construction. Statistical models describing the variation in these losses are presented, highlighting the limitations of the static assumptions commonly utilized in power distribution network planning. On this basis, an approximation of the time evolution of the transformer’s total power and energy losses is proposed as appropriate for implementation in a life-cycle analysis model. Furthermore, the impacts of thermal loading and abnormal operating conditions—such as unbalanced loads, frequent short circuits, and repeated overheating of the transformer oil—are analyzed as drivers of accelerated transformer aging. These effects are integrated into a unified life-cycle framework, enabling the quantitative assessment of loss variations and their associated operational expenditures (OPEX). A numerical example is provided to evaluate the cost-effectiveness of “repair vs. replacement” scenarios, utilizing a discounted cash flow analysis that incorporates a carbon component. The findings establish a methodological foundation for a broader assessment of technical condition and energy performance, identifying the optimal intervention point for repair or replacement to support decision-making for Distribution System Operators (DSOs) amidst increasing requirements for efficiency and decarbonization. Full article

Considering escalating global climate change, flood disaster risk assessment for architectural heritage must evolve from static models toward dynamic adaptive systems. This paper proposes a dynamic evaluation model based on the Full-Life-Cycle perspective, dividing disaster progression into three phases: pre-disaster, during-disaster, and post-disaster. This system constructs a dual-track indicator system encompassing Exposure and Vulnerability. By integrating the CRITIC objective weighting method with the G1 subjective ranking approach, the model enables dynamic weight adjustment according to disaster phase. A case study of 392 cultural heritage sites in Beijing reveals that during the disaster phase, 20 sites experienced a risk level increase in two or more tiers, with 13.7% directly entering high-risk status. This finding demonstrates the spatiotemporal evolution of flood risks. The weight for Road Network Density exhibited a substantial increase from 0.046 pre-disaster to 0.153 post-disaster, a 169.5% rise, underscoring its dynamic responsiveness. The findings demonstrate that the proposed model is effective in identifying high-risk heritage sites and dynamically capturing key targets experiencing rapid risk escalation within the disaster chain. These results provide quantitative evidence to support the implementation of phased targeted protection measures and emergency decision-making. Full article

Glass-Fiber-Reinforced Polymer (GFRP) bars are emerging as an alternative to steel reinforcement in concrete structures thanks to their high mechanical performance and intrinsic resistance to corrosion. Nevertheless, their actual sustainability must be verified through an assessment that considers long-term durability, life cycle environmental impacts, and economic feasibility. The replacement of steel reinforcement with GFRP in concrete bridge decks is herein evaluated through an integrated methodology. First, a comprehensive literature review examines the degradation processes observed experimentally and the associated long-term evolution of mechanical properties, providing the basis for defining realistic durability scenarios. Subsequently, a comparative Life Cycle Assessment is conducted adopting a cradle-to-grave system boundary and using Environmental Product Declarations to build the Life Cycle Inventory and perform the Impact Assessment. Normalization and weighting phases are included for a better understanding of the overall impacts of the two alternatives. In parallel, a Cost Analysis is performed consistently with the system boundaries and scenarios considered in the Life Cycle Assessment. Finally, the Envision protocol, a framework to evaluate sustainability and resilience of infrastructures, is applied to identify credits directly influenced by the adoption of GFRP reinforcement. The results show that steel reinforcement exhibits lower initial environmental impacts and remains more economical over short service life horizons. However, if the extended durability of GFRP is considered, the reduction in heavy maintenance activities allows this solution to achieve superior environmental performance and improved economic balance. The Envision-based evaluation further confirms the potential contribution of GFRP reinforcement to higher sustainability ratings in infrastructure projects. Full article

Traditional dwellings as the products of the combined effects of time, space and agency possess both a dynamic nature and historical continuity. With the progression of globalization and urbanization, the patterns of villages in Southwest China have transformed from enclosed, stable and homogeneous into open, dynamic and diverse. As crucial representations of rural spatial reconstruction and cultural evolution, the form and function of traditional dwellings are undergoing profound transformation and reorganization. The introduction of modern building methods and the shift in living concepts and aesthetic preferences intensify the impact on traditional building techniques, leading to a rupture in the traditional dwelling typological system. From a typological perspective, this study analyzes the transformation process and organizational characteristics of the traditional courtyard house prototype, as well as the social structures and cultural logic it reflects, by integrating the family life cycle, spatial concepts, and residential practices of Dai households. The findings indicate that Dai dwellings have undergone a four-phase typological process. The initial transformation was evident in the architectural details of the main rooms. Secondly, the spatial sequence embodying the clan order gradually disintegrated, and spaces with religious functions were continuously weakened, eventually being replaced by modern residential space dominated by standardized functional zoning. Concurrently, the layout of Dai dwellings was simplified from a four-sided courtyard house into a three-sided courtyard house and ultimately transformed into the layout primarily composed of independent, non-courtyard buildings. Its typological process reflects proactive adaptations to modern residential culture. However, this adaptive transition has also undermined the traditional Dai spatial order and cultural meaning, revealing a tension between cultural adaptation and cultural dissolution. Full article

The urgent need to decarbonize the global cement industry is compounded by the declining availability of conventional supplementary cementitious materials (SCMs). Limestone-calcined clay cement (LC3) emerges as a highly sustainable alternative, enabling up to 50 percent clinker replacement and an approximate 40 percent reduction in carbon dioxide emissions. Unlike existing reviews that focus on basic material properties, this paper critically bridges the gap between fundamental hydration thermodynamics and next-generation sustainable engineering applications. Through a structured bibliographic analysis of 135 contemporary sources published between 2000 and 2026, it traces the evolution of LC3 from a laboratory innovation to a highly promising solution for large-scale industrial implementation and circular economy integration. The discussion highlights the synergistic alumina carbonate reaction. This reaction forms carboaluminate phases. These phases significantly densify the microstructure and enhance long term durability. Key engineering properties are examined, contrasting rheological challenges from high water demand and carbonation susceptibility against its exceptional chloride resistance in aggressive environments. The transition to field application is thoroughly assessed, emphasizing technological advances in flash calcination, environmental footprint reduction through life cycle assessment (LCA), and production scalability. Finally, rather than restating known challenges, this review exposes the limitations of current empirical mitigation strategies. It proposes a targeted research agenda focused on molecular-level green admixture design and field calibrated durability models to support the integration of LC3 into emerging sustainable technologies such as 3D concrete printing. Full article

This review paper synthesizes the application and evolution of environmentally extended input–output (EEIO) analysis in agricultural research, drawing on 647 publications (Scopus and Web of Science, 1978–2025) following the PRISMA method and using the Bibliometrix package in the R statistical computing environment. EEIO has become a leading method for assessing system-level environmental impacts by quantifying direct and indirect flows across complete supply chains. Bibliometric and thematic analyses reveal accelerated growth since 2015 and four principal domains of enquiry: emissions embodied in trade, water-resource management, energy and climate impacts, and the sustainability of agri-food supply chains. EEIO’s principal value lies in its capacity to support production- versus consumption-based accounting and to reveal intersectoral trade-offs that single-sector approaches overlook. However, standard EEIO frameworks remain constrained by fixed technical coefficients, coarse sectoral aggregation, and uncertainty in environmental extensions, which limit their capacity to resolve farm-scale processes, structural change, and feedbacks. To enhance analytical rigor and policy relevance, we advocate hybridization with life-cycle and farm-level data, development of higher-resolution multi-regional EEIO tables, incorporation of stochastic and scenario analyses, dynamic formulations to capture technological change, and adoption of open-data standards with transparent reporting. Advancing these priorities will improve comparability, reproducibility and the practical uptake of EEIO for evidence-based transitions in agricultural systems. Full article

To address the challenges of limited access to full-life-cycle data and insufficient labeled samples in gas turbine health management, a Bidirectional Long Short-Term Memory-Domain Adversarial Neural Network (BiLSTM-DANN) is adopted to achieve cross-domain health assessment for gas turbines. The model extracts temporal health features with a two-layer BiLSTM network and integrates DANN to achieve cross-domain feature alignment, thereby learning domain-invariant health representations. The simulation results demonstrate that the BiLSTM-DANN model outperforms the traditional BiLSTM and DCNN models on both the FD001 and FD003 datasets of C-MAPSS. Health assessment tests conducted on real gas turbine operation datasets indicate that the BiLSTM-DANN model can effectively depict the long-term operational health evolution trend of the entire unit and accurately reflect the health changes of the gas turbine before and after water washing. Therefore, the method studied in this paper provides a transferable solution for assessing the health of the entire gas turbine under conditions of scarce labels. Full article