Search Results (3,056)

This article presents the results of a rockfall analysis conducted for the limestone walls of a former quarry that is now used as an urban park. The performed simulations (2D statistical analysis using Rigid Body Impact Mechanics—RBIM and Discrete Element Modelling—DEM) enabled the determination of the maximum displacement range during the ballistic phase and the maximum rebound height at the slope base, which facilitated the delineation of a safe land-use zone. A hazard zone was also identified, within which public access must be strictly prohibited due to the risk posed by flying debris. Based on slope stability assessments (safety factor values and rockfall trajectories), recommendations were formulated for slope reinforcement measures and appropriate management actions for designated sections to ensure safe operation of the site. Three mitigation strategies were proposed: (1) no protective measures, (2) no structural reinforcements but with installation of a rockfall barrier, and (3) full-scale stabilisation to allow unrestricted access to the quarry walls. The first option—leaving slopes unsecured with only designated safety buffers—is not recommended. Full article

Glacier retreat due to climate change is accelerating worldwide, yet the phenomenon remains abstract for many people, especially those unfamiliar with mountain environments. The Urban Glaciology experiment, conducted during Milan’s internationally renowned “Fuorisalone” 2024 design event, aimed to bridge this perceptual gap by simulating real glacier melt processes in a busy urban square. Three large ice blocks with contrasting surface conditions (i.e., clean, dirty, and debris-covered) were exposed to springtime urban temperatures, mimicking conditions found on Alpine glaciers during summer. Over one week, the blocks produced a total of 748 L of meltwater, with dirty ice melting up to four times faster than debris-covered ice, consistent with established albedo effects. These results confirmed the thermal analogy between Milan’s spring conditions (+15 to +20 °C) and the ablation season on Alpine glaciers. Visitors observed the differential melting in real time, supported by visual indicators, explanatory panels, immersive virtual experiences, and direct interaction with researchers and students. Informal interviews indicated that more than 60% of participants reported a perceptual shift, recognizing for the first time that urban temperatures can replicate glacier melting conditions. By embedding a science-based installation in a major cultural tourism event, the experiment reached a diverse, non-traditional audience—including tourists, designers, and citizens—and encouraged reflection on the implications of glacier loss. The success of this initiative highlights the potential of replicating similar models in other cities to raise awareness of environmental change through culturally engaging experiences. Full article

This study characterized the spatial distribution and assessed the ecological risks of carbon, nitrogen, and phosphorus in sediments of the Dongzhai Harbor mangrove wetland, Hainan, China. Analysis of key environmental indicators (grain size, pH, TOC, TN, TP) across twenty-seven sediment cores (0–100 cm depth) revealed distinct decreasing land–sea gradients and vertical stratification of nutrient concentrations. Mangrove plant debris was identified as the primary source of sedimentary organic matter. Elemental ratio analysis indicated terrestrial inputs as the dominant phosphorus source. Significant positive correlations between TOC, TN, and TP in surface sediments suggested coupled nutrient dynamics. Vertical distribution of C/N to C/P ratios increased with depth, which may be related to increased nitrogen and phosphorus inputs due to regional human activities. Pollution assessment showed significantly higher ecological risks in surface sediments (0–50 cm), particularly near inland areas and dense mangroves, indicating co-regulation by vegetation processes and human impacts. These findings highlight significant spatial heterogeneity in ecological risks, underscoring the need for enhanced monitoring and targeted management strategies in critical land–sea transition zones. Full article

In the mountainous and foothill areas of Santiago, Chile, debris flows and debris floods have been recurrent over recent decades, triggered by short-duration, high-intensity summer rainfall events. These events have caused significant damage to infrastructure and have affected the population, including loss of human lives. This study assesses the susceptibility to debris flow and debris flood generation in the Arrayán and Gualtatas stream basins, located in the Metropolitan Region, using satellite and cartographic data. A Susceptibility Index (SI) was determined through the analysis of 14 conditioning factors, grouped into three main categories: geology, geomorphology, and soil conditions. The weighting and ranking of each factor’s importance were carried out using the Analytic Hierarchy Process (AHP). The results, presented in a susceptibility map, indicate that 60.78% of the study area exhibits low to very low susceptibility, 24.64% moderate susceptibility, and 14.58% high to very high susceptibility, concentrated in stream headwaters, steep slopes, and areas with unconsolidated deposits. Recent debris flow events that have reached urban areas coincide with high-susceptibility zones, validating the methodology and cartographic products, which can support land-use planning and risk management efforts. Full article

This study examines research trends and identifies key gaps relevant to the field of structural safety and resilience; additionally, a systematic literature review (SLR) guided by the PRISMA methodology was conducted, analyzing 4188 documents ranging from 1975 to 2025. The research revealed key trends, including a focus on various aspects of the structural stability and resilience of buildings affected by earthquakes through analysis of various innovative methods and materials. The present study encompasses work describing the use of steel–wood composite columns to improve building stability, assessment of the impact of wood accumulation on bridges during floods, and the effect of debris flow on the stability of check dams. In addition, this study also evaluates the seismic performance of school buildings in Mexico, a method of diagnosing cracks in concrete dams, and the application of recycled materials from old tires for seismic disaster mitigation. Acoustic emission monitoring methods in medieval towers and the design of seismic isolation systems with variable damping are also discussed. Bibliometric analysis highlighted increased collaboration and a thematic shift towards green and data-driven approaches. However, significant gaps were identified. The findings explain that the use of innovative materials and methods can improve the stability and resistance of building structures with respect to dynamic loads, such as those associated with earthquakes and floods. The findings provide guidance for the design and maintenance of safer and more sustainable infrastructure in the future. Full article

Immune cells play a pivotal role in orchestrating tissue repair, executing functions such as debris clearance, extracellular matrix remodeling, and modulation of cytokine secretion profiles. However, when their activity is dysregulated or inadequately directed, these same processes can give rise to chronic inflammation and foreign body reactions (FBR), ultimately leading to fibrosis and compromised biomaterial performance. The immunological landscape following injury or biomaterial implantation is profoundly influenced by the physicochemical properties of material surfaces. By strategically tailoring these surface characteristics, it becomes possible to modulate immune cell responses—governing their adhesion, recruitment, proliferation, polarization, and cytokine expression patterns. This review elucidates the multifaceted roles of immune cells in tissue repair and their dynamic interactions with implanted biomaterials. It then explores how specific surface attributes—such as topography, chemistry, stiffness, and wettability—influence immune behavior. Particular emphasis is placed on recent advances in surface modification techniques aimed at engineering next-generation biomaterials that mitigate adverse immune responses while actively promoting regenerative healing. The review concludes by offering critical insights into the future of immunomodulatory biomaterial design, highlighting both emerging opportunities and persisting challenges in the field. Full article

Extracting road network information from satellite remote sensing images is an effective method of dealing with dynamic changes in road networks. At present, the use of deep learning methods to automatically segment road networks from remote sensing images has become mainstream. However, existing methods often produce fragmented extraction results. This is usually caused by insufficient feature extraction and occlusion. In order to solve these problems, we propose an enhanced feature extraction and multi-branch occlusion discrimination network (EFMOD-Net) based on an encoder–decoder architecture. Firstly, a multi-directional feature extraction (MFE) module was proposed as the input for the network, which utilizes multi-directional strip convolution for feature extraction to better capture the linear features of the road. Subsequently, an enhanced feature extraction (EFE) module was designed to enhance the performance of the model in the feature extraction stage by using a dual-branch structure. The proposed multi-branch occlusion discrimination (MOD) module combines the attention mechanism and strip convolution to learn the topological relationship between pixels, enhance the network’s detection of occlusion and complex backgrounds, and reduce the generation of road debris. On the public dataset, the proposed method is compared with other SOTA methods. The experimental results show that the network designed in this paper achieves an IoU of 64.73 and 63.58 on the DeepGlobe and CHN6-CUG datasets, respectively, which is 1.66% and 1.84% higher than the IoU of performance-based methods. The proposed method combines multi-directional bar convolution and a multi-branch structure for road extraction, which provides a new idea for linear object segmentation in complex backgrounds that could be applied directly to urban renewal, disaster assessment, and other application scenarios. Full article

Background/Objectives: This retrospective observational study evaluated associations among dentition type, age, systemic conditions, and oral pathology in pediatric patients. Methods: A six-month retrospective analysis was conducted in a specialized pediatric hospital. Patients (n = 155; 0–18 years) were grouped as clinically healthy with oro-maxillofacial diseases or with systemic diseases. Data included dental/periodontal status, anomalies, gingival bleeding index, IOTN score and oral mucosal conditions. Statistical tests (chi-square, ANOVA, and correlations) were applied. Results: Chronic gingivitis was most frequently associated with primary dentition. Caries and root debris were more frequent in ages 4–6, while acute gingivitis appeared in younger children. Orthodontic treatment need increased with age, especially in mixed dentition. Periodontal diseases were most often linked to digestive pathologies. Conclusions: Oral health in children showed associations with age, dentition type, and systemic conditions. Findings highlight associations rather than causation, underscoring the importance of prevention, early monitoring, and age-appropriate interdisciplinary management. Full article

The glaciers of the Nyainqêntanglha Mountains serve not only as sensitive indicators of climate change, but also as important water sources for downstream rivers. In this study, we quantitatively analyzed the glacier mass balance of the entirety of the Nyainqêntanglha Mountains using TerraSAR-X/TanDEM-X and SRTM DEM data and compared the mass balance between glaciers in the western and eastern parts of the range, revealing the spatial heterogeneity in glacier mass loss. Finally, data from nine meteorological stations in the region were used to investigate regional climate changes and their impacts on glacier variation. The results show that from 2000 to 2013, the average annual glacier surface elevation in the Nyainqêntanglha Mountains decreased by 0.48 ± 0.02 m, with a mass balance of −0.55 ± 0.04 m water equivalent per year. The majority of glacier mass loss occurred in areas with slopes between 40° and 70°. The mass loss of clean glaciers in the eastern region was higher than that in the western region, whereas at high elevations, the mass loss of debris-covered glaciers was more severe in the western region than in the east. Overall, the debris cover on the glaciers has not yet reached the critical thickness required to effectively mitigate melting, and mass input in the accumulation zones is uneven, scattered, and limited, resulting in weak replenishment capacity. Against the backdrop of continued warming, regional precipitation is insufficient to provide the necessary accumulation, making glaciers more sensitive to rising temperatures. This study not only reveals pronounced spatial differences in glacier mass loss and their climatic drivers but also provides new scientific evidence for understanding water resource security, hydrological responses and potential snow avalanche hazards on the Tibetan Plateau, offering important implications for regional water management and future climate adaptation. Full article

In response to the growing demand for sustainable biomaterials in tissue engineering, we investigated the potential of structurally intact brown seaweed scaffolds derived from Laminaria digitata (L.D.) and Laminaria saccharina (L.S.), produced by a detergent-free, visible-light decellularization process aimed at preserving structural integrity. Blades were submerged in cold flow-through and aerated water with red (620 nm) and blue (470 nm) light exposure for 4 weeks. Histology, scanning electron microscopy (SEM), and micro-computed tomography (micro-CT) analyses demonstrated that the light decellularization process removed cells/debris, maintained essential structural features, and significantly increased scaffold porosity. Mechanical property analysis through tensile testing revealed a substantial increase in tensile strength post decellularization, with L.D. scaffolds increasing from 3.4 MPa to 8.7 MPa and L.S. scaffolds from 2.1 MPa to 6.6 MPa. Chemical analysis indicated notable alterations in polysaccharide and protein composition following decellularization. Additionally, scaffolds retained high swelling and fluid absorption capacities, critical for biomedical uses. These findings underscore that the decellularized L.D. and L.S. scaffolds preserved structural integrity and exhibited enhanced mechanical properties, interconnected porous structures, and significant liquid retention capabilities, establishing them as promising biomaterial candidates for soft-tissue reinforcement, wound care, and broader applications in regenerative medicine. Full article

This study examines ground surface and air temperatures and their implications for periglacial activity in the Țarcu Massif, Southern Carpathians, where data on current dynamics and climate responses remain scarce despite widespread periglacial landforms. To address this, we deployed seven temperature loggers between 2018 and 2024 across a range of periglacial landforms, including non-sorted patterned ground, a periglacial hummock, protalus rampart, block stream, periglacial tor, ploughing boulder, and nival niche. We analyzed key thermal indicators such as freeze–thaw cycles, freezing and thawing degree days, frost weathering intervals, frost days, and winter equilibrium temperatures—in relation to long-term air temperature records (1961–2023), snow cover dynamics, and local topographic and substrate conditions. Results reveal a marked warming trend at the Țarcu meteorological station, particularly after 1995, along with a shift in net thermal balance beginning in the late 1990s. Since then, climatic conditions at this site have no longer been favorable for the persistence of sporadic permafrost. Ground thermal conditions varied spatially, with coarse debris sites and rock wall maintaining the lowest MAGST values—typically with 1 to 2.5 °C cooler than fine-grained sediments—and the highest potential for frost-related weathering. Despite low and variable freeze–thaw cycle frequency, the high number of frost days (around 200 per year) and sustained frost weathering potential—exceeding 50 days annually at key sites—indicate that periglacial conditions remain active for nearly half the year around 2000 m in the Southern Carpathians. Snow cover dynamics proved to be a major control on ground thermal behavior, with earlier melting and delayed onset shortening its duration but amplifying early winter cooling. These findings indicate that the Țarcu Massif is a transitional periglacial environment, where active and relict features coexist under growing climatic pressure. The ongoing decline in frost-driven processes highlights the vulnerability of mid-latitude mountain periglacial systems to climate warming and underscores the need for continued monitoring to better understand future landscape evolution in the Southern Carpathians. Full article

This study addresses engineering challenges associated with sandy residual deposits in the coastal zone of Quanzhou, China, characterized by high void ratios (e > 0.8), low cohesion (c < 10 kPa), and strong liquefaction tendencies induced by marine dynamic forces. Focusing on the beach sands of Shenhu Bay and Qingshan Bay, 123 in situ dynamic penetration tests and 12 laboratory physical–mechanical tests (including water content, particle gradation, relative density, and triaxial shear strength) were conducted. The correlations between the physical and mechanical properties of these coastal sandy soils and their foundation bearing capacity were systematically analyzed. Results reveal that the sands, predominantly medium-to-fine grains with 8–15% biogenic debris, are generally in a loose-to-medium dense state (relative density ~34%), with negligible cohesion. Shear strength depends primarily on the internal friction angle (28.89–37.43°). Correlation analyses show that water content (17.8–31.92%) and particle gradation parameters (uniformity coefficient C_u and curvature coefficient C_c) significantly influence bearing capacity, with bearing capacity increasing by 12.15% per 14.12% rise in water content and 35% per 0.518 increase in C_c. An improved foundation bearing capacity model based on the Prandtl–Reissner theory is proposed by integrating particle gradation and water content, tailored for beach foundations in Quanzhou. Model validation demonstrates an average error of approximately 15%, outperforming traditional models. These findings provide valuable theoretical support for assessing foundation stability in building construction projects in Quanzhou and similar coastal regions. Full article

Submarine gravity flows, e.g., debris flows and turbidity currents, pose a significant threat to offshore pipeline integrity. This risk primarily manifests through the imposition of substantial dynamic loads on pipelines or their large displacement when impacted by such flows. To enhance our understanding of these threats and facilitate the development of more robust pipeline design and protection strategies, this work reviewed the interactions between submarine gravity flows and offshore pipelines. For an individual pipeline, critical focus lies in characterizing the influence of key parameters—including Reynolds number, span height, impact angle, pipe geometry, ambient temperature, and surface roughness—on both the resultant impact forces and the fluid-structure interaction dynamics. Then, investigations into the interactions between gravity flows and multiple pipes are summarized, where the in-line spacing distance between two pipes is a key factor in reducing the impact force. Further, flow-induced vibration responses of a single pipeline and two tandem pipelines under gravity flows are presented. Building upon a thorough review, we conducted overall evaluations. There are few experimental studies and most investigations ideally treat the seabed to be horizontal, which does not always occur in practical engineering. Choosing empirical formulas to evaluate hydrodynamic loads should carefully consider the specific working conditions. An appropriate non-Newtonian fluid model is significantly important to avoid uncertainties. Some practical risk reduction measures such as streamlined structures and reduction in roughness are recommended. Finally, suggestions for future study and practice are proposed, including the requirement for three-dimensional numerical investigations, assessment of fatigue damage by flow-induced vibrations, consideration of flexible pipeline, and more attention to multiple pipelines. Full article

Accurate and real-time environmental perception is essential for the safe and efficient execution of deep-sea mining operations. Semantic segmentation of forward-looking sonar (FLS) images plays a pivotal role in enabling environmental awareness for deep-sea mining vehicles (DSMVs), but remains challenging due to strong acoustic noise, blurred object boundaries, and long-range semantic dependencies. To address these issues, this study proposes DSM-Seg, a novel hybrid segmentation architecture combining Convolutional Neural Networks (CNNs) and Receptance Weighted Key-Value (RWKV) modeling. The architecture integrates a Physical Prior-Based Semantic Guidance Module (PSGM), which utilizes sonar-specific physical priors to produce high-confidence semantic guidance maps, thereby enhancing the delineation of target boundaries. In addition, a RWKV-Based Global Fusion with Semantic Constraints (RGFSC) module is introduced to suppress cross-regional interference in long-range dependency modeling and achieve the effective fusion of local and global semantic information. Extensive experiments on both a self-collected seabed terrain dataset and a public marine debris dataset demonstrate that DSM-Seg significantly improves segmentation accuracy under complex conditions while satisfying real-time performance requirements. These results highlight the potential of the proposed method to support intelligent environmental perception in DSMV applications. Full article

This work introduces a comprehensive vision-based framework for autonomous space debris removal using robotic manipulators. A real-time debris detection module is built upon the YOLOv8 architecture, ensuring reliable target localization under varying illumination and occlusion conditions. Following detection, object motion states are estimated through a calibrated binocular vision system coupled with a physics-based collision model. Smooth interception trajectories are generated via a particle swarm optimization strategy integrated with a 5–5–5 polynomial interpolation scheme, enabling continuous and time-optimal end-effector motions. To anticipate future arm movements, a Transformer-based sequence predictor is enhanced by replacing conventional multilayer perceptrons with Kolmogorov–Arnold networks (KANs), improving both parameter efficiency and interpretability. In practice, the Transformer+KAN model compensates the manipulator’s trajectory planner to adapt to more complex scenarios. Each component is then evaluated separately in simulation, demonstrating stable tracking performance, precise trajectory execution, and robust motion prediction for intelligent on-orbit servicing. Full article