Search Results (2,138)

Accurate prediction of dam displacement is essential for structural safety and risk management. To comprehensively address the “accuracy–uncertainty–interpretability” trilemma in dam displacement prediction, this study proposes a deep learning framework that integrates Patch Time Series Transformer (PatchTST), Sand Cat Swarm Optimization (SCSO), Quantile Regression (QR), and SHapley Additive exPlanations (SHAP). The proposed framework first employs PatchTST to capture the nonlinear temporal dependencies between multiple monitoring factors and dam displacement, while SCSO is utilized to adaptively optimize key hyperparameters, enabling the construction of a high-precision point prediction model. On this basis, QR is introduced to model the distributional uncertainty of displacement responses and to generate confidence-based prediction intervals, facilitating the evaluation of displacement anomalies. Furthermore, SHAP is incorporated to quantify the marginal contribution of each input factor to the model outputs, thereby enhancing interpretability and aligning model behavior with physical domain knowledge. The framework is validated using multi-year monitoring data from a double-curvature arch dam located in Southwest China. Comparative experiments demonstrate that the proposed model outperforms five well-established machine learning methods and the traditional linear regression method in terms of point prediction accuracy, reliability of interval estimation, and false alarm rate, exhibiting strong generalization and robustness. The SHAP-based analysis further reveals that water pressure variations and seasonal temperature cycles are the dominant factors influencing radial displacement, consistent with known structural deformation mechanisms. These findings affirm the physical consistency and engineering applicability of the proposed framework, offering a deployable and trustworthy solution for intelligent dam health monitoring and uncertainty-aware forecasting in safety-critical infrastructures. Full article

CO₂-enhanced coalbed methane recovery (CO₂-ECBM) represents a promising pathway within carbon capture, utilization, and storage (CCUS) technologies, offering dual benefits of methane production and long-term CO₂ sequestration. This review provides a comprehensive analysis of CO₂-ECBM from a full-chain perspective (Mechanism, Practices, and Outlook), covering fundamental mechanisms and key engineering practices. It highlights the complex multi-physics processes involved, including competitive adsorption–desorption, diffusion and seepage, thermal effects, stress responses, and geochemical interactions. Recent progress in laboratory experiments, capacity assessments, site evaluations, monitoring techniques, and numerical simulations are systematically reviewed. Field studies indicate that CO₂-ECBM performance is strongly influenced by reservoir pressure, temperature, injection rate, and coal seam properties. Structural conditions and multi-field coupling further affect storage efficiency and long-term security. This work also addresses major technical challenges such as real-time monitoring limitations, environmental risks, injection-induced seismicity, and economic constraints. Future research directions emphasize the need to deepen understanding of coupling mechanisms, improve monitoring frameworks, and advance integrated engineering optimization. By synthesizing recent advances and identifying research priorities, this review aims to provide theoretical support and practical guidance for the scalable deployment of CO₂-ECBM, contributing to global energy transition and carbon neutrality goals. Full article

The prediction of the seismic response of non-yielding wall systems is complex. Over the years, researchers have presented numerous solutions to this problem, which often yield varying results concerning maximum forces, deformations, and the residual state of the system during a severe loading condition. In addition, few of the available methods of analysis can explicitly consider the compaction-induced lateral force when the backfill is dry, sandy soil and the wall is closer to a source of vibration. In this research, a numerical model is developed and validated by experiments to study the transient and residual dynamic responses of non-yielding walls supporting over-consolidated sand. A numerical parametric study is conducted, considering the effects of backfill soil friction angle, soil over-consolidation ratio, and wall modulus of elasticity. The response of the soil–wall system is investigated by considering the maximum and residual deformation of the wall, distribution of lateral earth pressure, as well as the magnitude and location of the resultant earth force. The findings of this study show that the maximum transient and residual forces and deflections often considerably exceed the static values in non-yielding walls subjected to ground motions. In general, increasing the backfill friction angle increases the maximum deflection and force increments. A surge in the backfill over-consolidation ratio reduces the maximum and the residual deflection and force increments. Finally, increasing the panel wall elastic modulus lowers the maximum and residual deflection increments, raises the maximum force increments, and decreases residual force increments. Results from the study on residual strength can be useful for implementation in performance-based design procedures under extreme loading conditions. Full article

Vegetation water-use efficiency (WUE), which represents the trade-off between carbon assimilation and water consumption, is a key indicator of ecosystem adaptation to environmental change. While previous studies have addressed the climatic controls on WUE in alpine ecosystems, the quantitative response mechanisms along elevation gradients remain insufficiently explored. This study investigated the growing season WUE patterns of alpine grasslands across elevation zones on the Qinghai–Tibetan Plateau by integrating partial correlation analysis and structural equation modeling (SEM). The findings revealed a clear triphasic pattern in WUE variation: a modest increase below 3000 m, a pronounced peak near 3700 m, and a steady decline at higher elevations. The dominant hydrothermal drivers shift with elevation. At lower altitudes, WUE was primarily influenced by the vapor pressure deficit (VPD), whereas soil temperature (ST) and VPD jointly govern WUE at mid-to-high altitudes. The SEM results indicated that the total effect of temperature on WUE increased from 0.51 at low elevations to 0.95 at high elevations, while the total effect of precipitation rose from −0.36 to −0.18. ST and VPD mediate the effects of temperature and precipitation on WUE, reflecting indirect and nonlinear regulatory pathways. Moreover, contribution rate analysis showed an elevation-dependent shift in WUE control: evapotranspiration (ET) exerted a dominant influence at low elevations (contribution rate: −82.50%), while net primary productivity (NPP) became the primary driver at high elevations (contribution rate: 54.71%). These findings demonstrate that alpine vegetation’s carbon–water coupling exhibits threshold-like behavior along altitudinal gradients, governed by differentiated hydrothermal constraints, offering new insights into ecosystem resilience under climate change. Full article

Water use efficiency (WUE), as an important metric for ecosystem resilience, has been identified to play a significant role in the coupling of carbon and water cycles. The farming–pastoral ecotone of Northern China (FPENC), which is highly susceptible to drought due to water scarcity, has long been recognized as an ecologically fragile zone. The ecological restoration projects in China have mitigated land degradation and maintain the sustainability of dryland. However, the process of greening in drylands has the potential to impact water availability. A comprehensive analysis of the WUE in the FPENC can help to understand the carbon absorption and water consumption. Using gross primary production (GPP) and evapotranspiration (ET) data from a MODerate resolution Imaging Spectroradiometer (MODIS), alongside biophysical variables data and land cover information, the spatio-temporal variations in WUE from 2003 to 2022 were examined. Additionally, its driving force and the ecosystem resilience were also revealed. Results indicated that the annual mean of WUE fluctuated between 0.52 and 2.60 gC kgH₂O⁻¹, showing a non-significant decreasing trend across the FPENC. Notably, the annual averaged WUE underwent a significant decline before 2012 (p < 0.05), and then showed a slight increased trend (p = 0.14) during the year afterward (i.e., 2013–2022). In terms of climatic controls, temperature (Temp) and soil volumetric water content (VSWC) dominantly affected WUE from 2003 to 2012; VPD (vapor pressure deficit), VSWC, and Temp showed comprehensive controls from 2013 to 2022. The findings suggest that a wetter atmosphere and increased soil moisture contribute to the decline in WUE. In total, 59.2% of FPENC was shown to be non-resilient, as grassland occupy the majority of the area, located in Mu Us Sandy land and Horqin Sand Land. These results underscore the importance of climatic factors in the regulation WUE over FPENC and highlight the necessity for focused research on WUE responses to climate change, particularly extreme events like droughts, in the future. Full article

This study examines the dynamic response of bottom-sitting steel shell structures subjected to underwater shock waves. A computational framework integrating the Arbitrary Lagrangian Eulerian (ALE) method was implemented in finite-element analysis to simulate three-dimensional interactions between shock waves and curved shell geometries (hemispherical and cylindrical configurations). An analysis of the impacts of shock-wave propagation media, explosive distance, charge equivalence, hydrostatic pressure, and shell thickness on the dynamic response of these bottom-sitting shell structures is conducted. The findings reveal that the deformation of semi-spherical steel shells subjected to underwater shock waves is significantly greater than that of shells subjected to air shock waves, with effective stress reaching up to 831.4 MPa underwater. The mechanical deformation of curved steel shells exhibits a gradual increase with increasing explosive equivalents. The center displacement of the hemispherical shell at 800 kg equivalent is 6 times that at 50 kg equivalent. Within the range of 0 to 2.0092 MPa, hydrostatic pressure leads to an approximate 26.34% increase in the center vertical displacement of the semi-cylindrical shell compared with 0 MPa, while restricting horizontal convex deformation. Increasing thickness from 0.025 m to 0.05 m results in a reduction of approximately 60% in the center vertical displacement of the semi-cylindrical shell. These quantitative correlations provide critical benchmarks for enhancing the blast resilience of underwater foundation systems. Full article

This study investigates damage characteristics of red sandstone under dynamic loads to clarify the effects of construction disturbances and blasting on the stability of surrounding rock during mountain tunnel construction in water-rich strata. Dynamic impact experiments at various loads were conducted using the Split Hopkinson Pressure Bar (SHPB) instrument, complemented by simulations of the fracturing process in saturated sandstone using finite element software. This analysis systematically examines the post-fracture granularity mass fraction, stress-strain curves, peak stress-average strain rate relationship, and fracture patterns. The dynamic response mechanism of red sandstone during the process of tunnel blasting construction was thoroughly investigated. Experimental results reveal that the peak stress and failure strain exhibit strain rate dependency, increasing from 45.65 MPa to 115.34 MPa and 0.95% to 5.23%, respectively, as strain rate elevates from 35.53 s⁻¹ to 118.71 s⁻¹. The failure process of red sandstone is divided into four stages: crack closure, nearly elastic phase, rapid crack development, and rapid unloading. Dynamic peak stress and average strain rate in sandstone demonstrate an approximately linear relationship, with the correlation coefficient being 0.962. Under different impact loads, fractures in specimens typically expand from the edges to the center and evolve from internal squeezing fractures to external development. Peak stress, degree of specimen breakage, and energy dissipation during fracturing are significantly influenced by the strain rate. The numerical simulations confirmed experimental findings while elucidating the failure mechanism in surrounding rocks under varying strain rates. This work pioneers a multiscale analysis framework bridging numerical simulation with a blasting construction site, addressing the critical gap in time-dependent deformation during tunnel excavation. Full article

Sloping seabeds are widely found in offshore areas, especially around coral reefs, where complex topography significantly affects wave–current propagation characteristics and seabed dynamic responses. However, previous studies have mainly focused on flat seabed cases, while investigations of sloping seabed responses around piles under wave–current interaction is limited. In this study, a three-dimensional numerical model is used to investigate the wave–current-induced sloping seabed response around a monopile. By comparing the variations in pore pressure and effective stress around the pile, the spatial heterogeneity of the seabed dynamic response was revealed. The results show that the variation in current velocity significantly affected the distribution of pore pressure and effective stress. Moreover, the disturbances on both lateral sides of the pile tended to stabilize as the current velocity increased, and the amplitude of the free surface gradually approached a steady state. This research fills the gap in the field of wave–current-induced sloping seabed response around piles and provides a theoretical basis for the analysis of offshore pile foundation stability under complex terrain conditions. Full article

This study aimed to optimize the ultrasound-assisted extraction (UAE) process using food-grade ethanol to recover glucosinolates from upcycled cauliflower through response surface methodology. The optimized extraction process was compared with traditional extraction using maceration with solvents such as methanol and acetone. The optimum UAE conditions identified for extracting glucosinolates from upcycled cauliflower were: 42% ethanol as solvent at 43 °C for 30 min. The total glucosinolate content recovered was 7400 μg sinigrin equivalence (SE)/g dry weight (DW) of biomass. The ultra-pressure liquid chromatography–electrospray ionization-mass spectrometry (UPLC-ESI-MS) analysis confirmed that the optimized UAE yielded the highest levels of glucoraphanin (1.31 ± 0.12 μg/g DW of biomass) and sulforaphane (28.2 ± 3.34 μg/g DW of biomass). The extracts possess greater antioxidant activity as determined by ferric reducing antioxidant power and DPPH radical scavenging activity. The optimized UAE process significantly enhanced the extraction of valuable phytochemical molecules from the upcycled cauliflower. Further studies should focus on evaluating their therapeutic and preventive potential for applications in nutrition and health. Full article

In response to global concerns about climate change and decarbonization across every sector, pressure has mounted on the maritime industry to reduce its environmental impacts, specifically its greenhouse gas (GHG) emissions, representing around 2.8% of the global total. As such, it prompts new alternative fuels that align with the International Maritime Organization (IMO)’s 2050 net-zero target. In recent years, several alternative fuels, such as hydrogen, ammonia, and methanol, have been proposed. However, alternative fuels face many challenges regarding cost, safety, and efficiency compared to traditional fossil fuels. Currently, methanol is considered one of the most promising alternatives since it is available, easy to store, and can take full advantage of existing infrastructure in situ. Moreover, methanol has a lower carbon intensity than conventional fossil fuels. However, its usage poses related risks of toxicity and flammability; thus, this area still needs in-depth research regarding hazard control. This study implements a systematic five-step methodology. Through a comprehensive literature review, the predominant hazards are delineated. To systematically analyze these risks, this study introduces a novel hazard-based coding system developed to categorize hazards into three classifications: toxicity, flammability, and explosivity. This system is specifically designed to analyze qualitative reports from thirty methanol accident investigations utilizing MAXQDA software. Subsequently, safety barriers related to methanol are identified, followed by a gap analysis to evaluate the effectiveness of existing safety measures. The findings indicate that physical hazards, including flammability and explosivity, represented the majority of identified risks. Furthermore, tank explosions emerged as a prominent sub-hazard, frequently linked to the highest number of reported fatalities. A gap analysis delineates the identified barriers related to Equipment and Personal Protective Equipment (PPE), Human Error Reduction, the Legal Framework, and First Aid, comparing them against the current measures outlined in IMO Circular 1621 and other legislative frameworks. Consequently, the analysis highlights critical gaps in technical guidelines and operational procedures related to methanol use. The study recommends the development of fuel-specific safety protocols, mandatory training for seafarers, and regulatory updates to address the unique hazards of methanol. These measures are necessary to create higher safety standards and make methanol a viable alternative fuel by ensuring its safe integration into the industry. Full article

This study focuses on Neogene red-bed soft rock tunnels in the Huicheng Basin, China. Through engineering geological investigation, remote wireless monitoring systems, and total station multi-parameter monitoring, the deformation characteristics of red-bed soft rock surrounding rock under high in situ stress environments and their influencing factors were systematically analyzed. The findings reveal that the surrounding rock deformation follows a three-stage evolutionary pattern of “rapid, slow, and stable”. Construction disturbances can disrupt the stable state, leading to “deep V-shaped” anomalies or double-step responses in deformation curves. Spatially, the deformation exhibits significant anisotropy, with the haunch area showing the maximum deformation (95 mm) and the vault the minimum (65–73 mm). Deformation stabilization requires 30–42 days, and a reserved deformation of 10 cm is recommended based on specifications. Mechanical behavior analysis indicates that the stress–strain curves of red-bed argillaceous sandstone are stepped, with increased confining pressure enhancing both peak and residual strengths, validating the necessity of timely support. The study elucidates a multi-factor coupling mechanism: rock mass classification, temporal–spatial effects (excavation face constraints and rheological properties), construction methods, in situ stress levels, and support timing (timely support during the rapid phase inhibits strength degradation) significantly influence deformation evolution. The spatiotemporal distribution of surrounding rock pressure shows that invert pressure increases most rapidly, while vault pressure reaches the highest magnitude, with construction disturbances triggering stress redistribution. This research provides theoretical and practical guidance for the design, construction optimization, and disaster prevention of red-bed soft rock tunnels. Full article

This study extends the method of pseudo-dynamic analysis based on the Mononobe-Okabe (M-O) method by comprehensively incorporating the seismic acceleration response characteristics of backfill soil and the cohesive properties of the fill. The proposed method is adapted for backfill soils by incorporating the cohesion c and internal friction angle φ (including scenarios with non-horizontal backfill surfaces). Theoretical formulas for the active earth pressure coefficient and its distribution on rigid retaining walls under the most unfavorable conditions are derived. The rationality of the proposed formulas is preliminarily verified using model test data from the relevant literature. A detailed parametric sensitivity analysis reveals the following trends: The active earth pressure coefficient K_a increases with increases in the amplification factor f_a, wall backface inclination angle θ, backfill slope inclination i, lateral vibration period T, and horizontal seismic acceleration coefficient k_h; K_a decreases with an increasing internal friction angle φ and cohesion/unit weight ratio c/γH. The failure wedge angle α_a increases with increases in φ, θ, and c/γH, decreases with increases in f_a, the soil–wall friction angle δ, i, T, k_h, and the vertical seismic acceleration coefficient k_v. Calculations are carried out to further identify the critical tensile stress depth in cohesive backfill soils using c and φ. The proposed analysis highlights the necessity of considering the seismic acceleration amplification factor f_a, backfill cohesion c, and soil–wall adhesion c_w in active earth pressure calculations. This study recommends that the seismic design of retaining walls should involve appropriate evaluation of the the actual cohesion of backfill materials and fully account for the acceleration amplification effects under seismic loading. Full article

Increases in flow elicit dilations in the basilar artery (BA) supplied by the posterior cerebral circulation (PCC), and ensuring efficient blood supply to the circle of Willis in which blood flow and pressure can distribute and equalize, and thus provide the appropriate supply for the daughter branches to reach certain brain areas. In contrast, increases in flow elicit constrictions in the middle cerebral artery (MCA), supplied by the anterior cerebral circulation (ACC) and regulating the blood pressure and flow in distal cerebral circulation. Mediators of flow-dependent responses include arachidonic acid (AA) metabolites and nitric oxide (NO). We hypothesized that mediators of flow-dependent responses are differentially expressed in cerebral arteries of the PCC (CA_PCC) and ACC (CA_ACC). The expressions of key enzymes of the AA pathway—cyclooxygenases (COX1/COX2), cytochrome P450 hydroxylases (Cyp450), thromboxane synthase (TXAS), thromboxane A2 (TP) receptor, prostacyclin synthase (PGIS), prostacyclin (IP) receptor (IP); neuronal nitric oxide synthase (nNOS), and endothelial nitric oxide synthase (eNOS)—in the BA and MCA from rats (n = 20) were determined by western blotting. Transcriptome analysis in CA_PCC and CA_ACC from rats (n = 25) was assessed by RNA sequencing. In BA compared to MCA, COX1/2 and Cyp450 protein expressions were lower, PGIS was higher, TXAS and nNOS/eNOS were similar, TP receptors were lower, and IP receptors were higher. Gene expressions of vasodilator canonical pathways were higher in CA_PCC; vasoconstriction canonical pathways were higher in CA_ACC. Mediators of flow-dependent vasomotor signaling are differentially expressed in cerebral arteries of the posterior and anterior circulation, corresponding to their vasomotor function. Full article

This study employs walking interviews to examine the low-carbon practices, cultural adaptation, and policy awareness of older Chinese migrants in the UK within their everyday environments. A total of 20 participants were interviewed in public spaces such as parks, supermarkets, and their homes. Using contextual thematic analysis, the study identifies key factors influencing their environmental behaviors. The findings reveal the following: (1) Language barriers, economic pressures, and social isolation limit migrants’ understanding of environmental policies. Many participants rely on self-sufficient ethnic community networks rather than engaging with mainstream sources; (2) Generational differences are evident—younger migrants demonstrate greater theoretical awareness of environmental policies, whereas older migrants exhibit stronger low-carbon behaviors through energy conservation and waste reduction; (3) A balance between cultural identity and consumption habits—while some migrants adjust their dietary, spending, and linguistic habits, core cultural values such as frugality and family responsibility remain unchanged. This study highlights the value of walking interviews in capturing situational insights into low-carbon behaviors and cultural adaptation. It provides empirical evidence for government agencies and community organizations, advocating for cross-cultural environmental education and improved policy communication. Recommendations include targeted environmental training, community-based volunteer initiatives, intergenerational environmental education, and policy dissemination through WeChat, Chinese communities, and ethnic networks. These measures can help bridge the generational gap in policy awareness and promote social integration among older Chinese migrants. Full article

This study investigates pressure relief mechanisms and gas migration control in gently inclined remote lower protective layer mining, using the Wu_8-31220 working face of Pingdingshan Tianan Coal Industry’s No. 1 Mine as a prototype. The integrated approach combining theoretical modeling with multidimensional monitoring systems yielded critical insights into pressure relief patterns. Analysis demonstrated dip-oriented pressure relief angles measuring 77° (intake side) and 83° (return side), collectively establishing a pressure relief zone spanning 160.5 m. Concurrently, horizontal pressure relief angles were determined to be 60° in both orientations, generating a pressure relief zone extending 1261 m. Mechanical monitoring revealed multistage “compression–expansion” responses in the Ding6 seam during protective seam extraction, achieving maximum expansion deformations of 9.89–13.55‰ within the boundary zone. By optimizing borehole spacing (20 m) and extraction duration (8 months), the Ding_6-32070 working face extracted 1.18 million m³ of gas (31.22% reserves), resolving spatial coupling challenges between gas recovery efficiency and pressure relief dimensions. This work advances understanding of pressure relief and permeability enhancement in gently inclined remote lower protective layer mining. The findings provide both theoretical foundations and technical benchmarks for safe deep coal mining operations and efficient gas control strategies. Full article