Search Results (6,046)

Earthquake-induced landslides represent a critical threat to transportation infrastructure in tectonically active mountainous regions, particularly in tropical volcanic settings where weak, highly weathered geomaterials dominate. This study develops an integrated framework that directly links physically based seismic threshold modelling with real-time landslide monitoring and operational early warning. The approach is demonstrated in the Cugenang area of Cianjur Regency, West Java, Indonesia, which was severely impacted by the moment magnitude (Mw) 5.6 earthquake in 2022. Slopes composed of highly weathered pyroclastic deposits [Plasticity Index (PI) = 54–68%; porosity > 60%] exhibit low shear strength and high sensitivity to seismic loading. Limit equilibrium analysis using the Morgenstern–Price method that combines the influence of seismic loading and groundwater conditions suggests that a horizontal seismic coefficient (kh) of approximately 0.06, corresponding to a Peak Ground Acceleration (PGA) of about 0.12 gravitational acceleration (g), is a critical threshold for initial landsliding. This comparatively low threshold challenges commonly reported values and demonstrates that slope failure in tropical volcanic terrains can occur under moderate ground shaking, reinforcing the need for site-specific hazard characterisation. The derived thresholds are operationalised within a multi-sensor early warning system integrating Micro-Electro-Mechanical Systems (MEMS) accelerometers and inclinometer measurements. Three hazard levels—Normal (<0.06 g), Alert (0.06–0.12 g), and Emergency (≥0.12 g)are combined with deformation thresholds [<10 milimeter (mm), 10–30 mm, >30 mm] to capture progressive failure processes and minimise false alarms. By coupling geotechnical modelling and real-time monitoring, this study provides a transferable and scalable framework for enhancing infrastructure resilience in landslide-prone regions. Full article

Accurate identification of flooded layers by cased-hole logging is a critical challenge for fine-scale development and enhanced oil recovery in water-flooded oil fields at medium to high water-cut stages. Conventional methods based on single-series logging or two-dimensional crossplot techniques are inadequate for the fine-scale interpretation of complex low-permeability reservoirs. This paper proposes a novel flooded layer identification method through the deep integration of dynamic and static data. The proposed approach organically couples static open-hole logging data (porosity, resistivity, etc.) with dynamic cased-hole logging data (pulsed neutron macroscopic capture cross-section Σ and carbon–oxygen ratio, C/O) within a three-dimensional (3D) crossplot framework. A multidimensional feature parameter space is constructed, and a spatial distance-ratio model is established to quantitatively calculate the flooding index Fw for continuous evaluation of flood level (non-flooded, weakly flooded, moderately flooded, and strongly flooded). Field application in Well X of a low-permeability oil field successfully identified two ambiguous apparent water layers as weakly flooded layers, previously indistinguishable using traditional 2D methods, with interpretation results highly consistent with subsequent production tests. The identification accuracy reached over 90.7%, providing a scalable technical framework for cased-hole flooded layer evaluation in medium-to-low-permeability complex reservoirs. Full article

To address the inherent drawbacks of micro-arc oxidation (MAO), this study employed MAO combined with sol–gel processing to fabricate ZrO₂/Al₂O₃-CeO₂ composite coatings on ZrH_1.8 surfaces, aiming to solve the hydrogen evolution problem of zirconium hydride (ZrH_1.8) materials in high-temperature environments. By adjusting the aluminum concentration in the sol (0.1~0.5 mol/L), a series of composite thin films were prepared on the ZrH_1.8 surface using MAO combined with dip-coating, and their surface morphology and phase composition were characterized. The microstructure, morphology, and hydrogen barrier performance of the thin films were systematically analyzed using scanning electron microscopy (SEM), XRD, laser confocal microscopy, and quadrupole mass spectrometry. The results showed that the composite coating had a low surface porosity, with a maximum hydrogen permeation reduction factor (PRF) of 18.1. When the aluminum concentration was 0.4 mol/L, the relative content of tetragonal ZrO₂ (T-ZrO₂) reached 13.88%, the surface porosity was as low as 4.87%, and the initial temperature of hydrogen loss was increased to 730 °C. Mechanism analysis indicated that CeO₂ may stabilize the tetragonal phase (T-ZrO₂) of ZrO₂ through solid solution effects and inhibit the phase transformation to monoclinic phase (M-ZrO₂), thereby reducing cracks caused by volume expansion. Meanwhile, the synergistic effect of the MAO densified layer and the sol–gel sealed porous layer significantly reduced the coating porosity and blocked hydrogen diffusion paths, thus achieving excellent hydrogen barrier performance under high-temperature conditions. Full article

Lattice-based heat sinks have attracted increasing attention as volumetric thermal management architectures for forced-convection cooling of high-power electronic systems. In contrast to conventional plate-fin, pin-fin, and straight-channel configurations, lattice geometries promote three-dimensional flow–solid interaction through interconnected ligament networks that modify boundary-layer development, wake formation, and internal heat-spreading pathways. This review synthesizes recent experimental and numerical studies to examine the thermo-fluid mechanisms governing lattice performance, with emphasis on the coupled influence of porosity, ligament dimensions, topology, orientation, and channel confinement on heat-transfer enhancement and hydraulic resistance. The analysis indicates that while lattice structures can increase average Nusselt number and improve temperature uniformity, these gains are intrinsically linked to pressure-drop penalties associated with flow tortuosity and form drag, resulting in regime-dependent thermal-hydraulic behavior. Apparent discrepancies reported across the literature are frequently attributable to differences in geometric definition, Reynolds-number normalization, and boundary-condition specification rather than to inconsistencies in physical mechanisms. By consolidating geometric scaling, performance metrics, manufacturing considerations, and system-level constraints, this review clarifies the conditions under which lattice heat sinks may provide net benefit relative to conventional cooling technologies and identifies key research directions required to support application-relevant design and evaluation. Full article

Precise segmentation of weld defects offers clearer advantages over simple localization in the modern manufacturing, which can improve reliability in high-density weld zones. In order to improve the segmentation mean Average Precision (mAP) and inference speed, we propose a hybrid WFD-YOLO that employs a wavelet-based frequency down-sampling (WFD) module, a lightweight channel-thresholding attention (CTA), and a dedicated P2 small-object layer for weld defect segmentation, where the WFD module is used for suppressing aliasing while preserving low-frequency structural details, the CTA module is used for reducing the impact of background and noise during defect segmentation, and the dedicated P2 small-object layer is used for giving explicit sensitivity to minor defects like porosity and spatters. The upgraded model improves precision by 3.5%, recall by 7.8%, mAP@0.5 by 7.3%, and mAP@0.5–0.95 by 2.7% over the original YOLO11n-seg, while achieving an inference speed of 303 FPS. The segmentation mAP for porosity and spatters, which represent the most challenging defect categories, is improved by 16% and 15.8%, respectively. These performance gains position the hybrid WFD-YOLO network as an industry-deployable tool for safety-critical weld inspection, compatible with high-speed automated welding production lines. Full article

Background: Polymeric drug-eluting films are promising platforms for local antibacterial delivery, but their release profiles depend strongly on the permeability and morphology of the barrier layer. Here, the previously proposed concept of additively manufactured PLACE (Printed Layered Adjustable Cargo Encapsulation) coatings was extended from "single orifice"-defined release toward porosity-assisted barrier control. Two conventional water-soluble porogens, polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP), were compared with poly(2-ethyl-2-oxazoline) (PEOx), a hydrophilic polymer proposed as an alternative to PEG in biomedical formulations, but whose use as a leachable porogen has received little attention. Methods: Each porogen was introduced into the upper PLGA barrier of multilayer PLACE films. The resulting films were characterized for film formation, post-hydration morphology by SEM, release of methylene blue and vancomycin, and antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). Results/Conclusions: PEG was poorly compatible with PLGA and mainly produced surface-localized defects rather than a barrier with controlled permeability suitable for prolonged delivery. PVP K17 provided sustained release at 10 wt.%, whereas 20 wt.% PVP caused burst-dominated release and stronger morphological disruption. PEOx formed developed porosity at lower loading and produced release regimes ranging from several days to approximately two weeks. Vancomycin-loaded films containing 5 wt.% PEOx enabled near-complete release over two weeks while preserving film integrity and showed pronounced early anti-MRSA activity. These results identify porogen selection as a key formulation step and support PEOx as a useful porogen for early high-output antibacterial PLACE coatings. Full article

Hydraulic fracturing is the core technology for stimulation and reform of low-permeability and unconventional oil and gas reservoirs. Reservoir fracability directly determines fracture morphology, complexity, and stimulated reservoir volume. To address the shortcomings of existing fracability evaluation models, such as poor applicability, subjective weighting and insufficient accuracy, five key indicators are selected, including brittleness index, brittle mineral index, stress difference coefficient, minimum horizontal principal stress and porosity. First, the three-dimensional discrete lattice method is used to clarify the influence of each parameter on fracture complexity. Then, the Analytic Hierarchy Process (AHP) and Entropy Weight Method (EWM) are combined to determine the indicator weights, a continuous fracability evaluation model is constructed, and a classification standard for fracturing applicability is established. The results show that the brittleness index has the greatest influence on fracture complexity with a weight of 0.3559, followed by brittle mineral index (0.2986), minimum principal stress (0.1994), stress difference coefficient (0.0993) and porosity (0.0467). The reservoir fracability indices of 0.37 and 0.59 are the mutation points of fracture complexity. Based on microseismic evaluation of stimulated reservoir volume (SRV) using an envelope surface method, it is found that reservoirs with low fracability are more suitable for fracturing designs characterized by large cluster spacing, fewer clusters, and smaller stage spacing. In contrast, reservoirs with medium and high fracability can develop more complex fracture networks by reducing cluster spacing, increasing the number of clusters, and adopting higher pumping rates. The research results can provide theoretical basis and technical support for hydraulic fracturing operation design. Full article

This work presents a case study of sensitivity analysis applied to the modeling of ethanol steam reforming (SRE) in a catalytic porous medium, with a focus on hydrogen production. Considering the high variability of parameters reported in the literature, the objective is not to propose a universal model, but rather to assess the impact of uncertainties associated with input parameters on the model outcomes. The model was developed under steady-state conditions, coupling flow in porous media, species transport, and heat transfer, with kinetics described as a function of partial pressures. The sensitivity analysis was conducted through the systematic variation of kinetic and physicochemical parameters within ranges associated with their uncertainties. The results indicate that activation energy is the parameter most sensitive to uncertainty variation, exhibiting the greatest impact on hydrogen production. The thermal properties of the medium, particularly thermal conductivity and solid density, also stand out, highlighting the role of thermo-kinetic coupling. In contrast, parameters such as porosity, water reaction order, and particle diameter exhibited low sensitivity under the analyzed conditions. As a main contribution, this work establishes a sensitivity hierarchy associated with parameter uncertainties and provides guidance for other researchers regarding the prioritization of their determination and calibration in hydrogen production models. Full article

This study investigates the effect of laser powder bed fusion (L-PBF) parameters and T7 heat treatment on the defect formation, microstructure, and mechanical properties of a high-strength Al-Cu 224 aluminum alloy. The laser power (200–370 W), scanning speed (130–1900 mm/s), and hatch spacing (90–130 μm) were varied to evaluate their influence on hot cracking and porosity. Microstructural characterization using optical microscopy, scanning electron microscopy, and electron backscatter diffraction revealed that an energy density of 400 J/mm³ substantially reduced visible hot cracking in the examined microscopic regions by reducing the thermal gradients. However, this resulted in increased keyhole porosity, thereby limiting the relative density to 95%. The as-built samples exhibited a yield strength of 152 MPa and an elongation of 9.2%, and the T7 heat treatment improved the yield strength to 233 MPa, whereas the elongation remained unchanged. Keyhole pores served as primary crack initiation/propagation sites during tensile loading, reducing ductility. Lower energy densities increased the geometrically necessary dislocation density and promoted cracking because of higher residual stresses due to greater accumulated plastic strain and lattice curvature. These results clarify process–structure–property relationships, emphasize the trade-offs between defect types and performance, and provide a robust framework for optimizing L-PBF processing of high-strength Al alloys through parameter tuning and post-heat treatment. Full article

Red clay in humid-hot environments suffers from severe water sensitivity and rainfall-induced slope instability, while traditional cement/lime stabilization faces high carbon emission challenges. Existing studies on plant ash-modified red clay mainly focus on basic mechanical properties, while systematic research on water retention characteristics and slope stability under extreme rainfall in humid-hot climates remains insufficient. To address this gap, this study proposes a sustainable stabilization method using agricultural waste-derived plant ash for red clay modification in humid-hot regions. Red clay exhibits distinct engineering behaviors owing to its unique physicochemical properties, leading to compromised slope stability and reduced resistance to rainwater infiltration. In this study, red clay was stabilized with 5%, 10%, 15%, and 20% plant ash. Laboratory tests evaluated compaction characteristics, shear strength, and water retention, supported by microstructural analysis via scanning electron microscopy (SEM). Slope stability under rainfall conditions was further simulated using ABAQUS 2022 software. Key findings include: (1) The addition of plant ash significantly altered the compaction properties. As the plant ash content increased from 0% to 20%, the maximum dry density of the modified red clay decreased linearly from 1.68 g/cm³ (unmodified soil) to 1.53 g/cm³, while the optimum moisture content rose from 21.86% to 23.85%. (2) The mechanical properties exhibited a non-linear response, peaking at 10% ash content. At this optimum dosage, the unconfined compressive strength, cohesion, and internal friction angle increased by 70.4%, 83.0%, and 37.1%, respectively, compared to untreated soil. (3) Plant ash enhanced water retention capacity, shifting the soil-water characteristic curve (SWCC). The modified soil demonstrated faster dehydration at low suction but improved water retention at high suction. The permeability coefficient decreased by an order of magnitude. Microstructural analysis revealed reduced porosity and fracture infilling by cementitious gels. (4) Numerical simulations confirmed that 10% plant ash reduced maximum slope displacement from 0.96 m to 0.61 m under heavy rainfall (90 mm total precipitation over 36 h, peak intensity 90 mm/day), elevating the safety factor from 0.85 to 1.45. Failure modes transitioned from deep-seated slip to localized shallow erosion. These results demonstrate that plant ash is a sustainable and effective additive for red clay slope stabilization in tropical climates. Full article

In recent years, oil spill accidents and oily wastewater discharge have posed severe threats to aquatic ecosystems and human health. Developing green, low-cost, efficient, and recyclable oil–water separation materials is therefore important for environmental remediation. In this work, kaolin/cellulose composite aerogels were fabricated through a low-temperature NaOH/urea dissolution system using N,N′-Methylenebisacrylamide (MBA) as the cross-linking agent, followed by freeze-drying and hydrophobic modification with Methyltrimethoxysilane (MTMS). The structure, morphology, thermal stability, wettability, mechanical behavior, oil adsorption capacity, and reusability of the aerogels were systematically investigated. The composite aerogels exhibited a honeycomb-like interconnected porous structure with low density and high porosity. Kaolin acted as an inorganic reinforcing and roughness-regulating component, which promoted the formation and anchoring of an MTMS-derived siloxane/SiO₂-like hydrophobic layer on the aerogel surface. The modified aerogels showed superhydrophobicity with a water contact angle above 152° and excellent oleophilicity. The optimized SC3K0.5 aerogel delivered adsorption capacities of 13.5 g/g for pump oil and 12.5 g/g for diesel. After 10 adsorption–desorption cycles, the adsorption capacity remained above 90% of the initial value, indicating good recyclability and mechanical stability. This recyclable kaolin/cellulose aerogel provides a feasible strategy for practical oil–water separation and oily wastewater treatment. Full article

This study aimed to determine the optimal biochar application rate for sustaining cotton productivity in moderately saline soils under dry sowing with wet emergence (DSWE) conditions in Shaya County, Xinjiang. A two-year field experiment, arranged in a randomized complete block design with two replicates, evaluated six biochar application rates (S1–S6) against a non-amended control (CK). The biochar, derived from fruit-wood via limited-oxygen pyrolysis at 500 °C (pH 9.82, porosity 64.5%), was applied as a single pre-sowing amendment. Soil water–salt dynamics, crop emergence, and growth parameters were continuously monitored. The results indicated that biochar application consistently reduced soil salinity; specifically, seedling-stage salinity decreased by 30.1–42.2% in the first year compared with the CK. Cotton emergence and yield improved significantly across both seasons. However, the optimal application rate for maximizing yield varied between years. While a high rate (S5: 25 t·hm⁻²) produced the highest first-year yield (6243.8 kg·hm⁻²), a moderate rate (S3: 15 t·hm⁻²) demonstrated greater yield stability and achieved the maximum yield (5975.2 kg·hm⁻²) in the second year. This interannual shift is likely attributable to biochar aging and structural pore saturation in the high-dose plots. Combined with high regional evaporation, these factors exacerbated secondary salinization and reduced the residual benefits of the amendment over time. In contrast, the moderate dose maintained a more effective balance between continuous water–salt regulation and nutrient availability. Under the experimental conditions, a single pre-sowing application of 15 t·hm⁻² biochar, combined with a 375 m³·hm⁻² drip irrigation volume, is recommended as an effective strategy to ameliorate salinity and support long-term yield stability. Full article

Metal–organic frameworks (MOFs) are crystalline porous materials made of metal nodes coordinated by organic linkers. Their high surface areas, tunable pore sizes, adjustable chemical environments, and modular design make MOFs promising for two main application domains: environmental remediation and energy conversion or storage. In this review, we explore the applications of both newly designed MOFs and MOF-derived materials. These applications include catalysis, electrocatalysis, sensing, pollutant removal, batteries, supercapacitors, and other hybrid energy devices. We attempt to correlate MOF structure with key parameters, such as metal centers, ligands, defects, and porosity, to performance. We also discuss the future use of MOFs in real-world devices. This depends on overcoming challenges such as scalability, conductivity, stability, and environmental safety. Full article

Tunnel seepage in heterogeneous ground can trigger hydrogeological hazards such as concentrated water inflow, groundwater depletion, deformation of surrounding structures, and subsequent eco-environmental degradation. However, these processes are still commonly evaluated using deterministic models that neglect the spatial variability of hydrogeological parameters. To address this limitation, this study develops a stochastic hydro–geo–mechanical–ecological framework that integrates random field theory with physics-informed neural networks (PINNs) for hazard evaluation and rapid prediction of tunnel seepage responses. The spatial variability of key parameters, including permeability and porosity, is characterized using the Karhunen–Loeve expansion and embedded into coupled governing equations for unsaturated–saturated seepage, seepage–stress interaction, and groundwater–soil–vegetation responses. A PINN surrogate model with random-field inputs is then constructed to predict hydraulic head, tunnel inflow, displacement, groundwater depth, vegetation coverage, and soil physicochemical indices, while simultaneously quantifying uncertainty. A karst tunnel case in Chongqing, China, is used to demonstrate the proposed framework. The results show that spatial heterogeneity promotes preferential flow paths and intensifies seepage-induced hazards compared with deterministic mean simulations, leading to larger groundwater drawdown, stronger ecological degradation, and greater overall response variability. The proposed PINN achieves high predictive accuracy (R² > 0.97) and reduces single-case computational time from hours to seconds, enabling efficient multi-scenario evaluation and uncertainty-aware risk assessment. This framework provides a physically consistent and computationally efficient tool for evaluating water-related hazards and long-term environmental impacts in underground engineering. Full article

To investigate changes in seismic wave propagation in different types of igneous rocks under dry and water-saturated conditions, this study employed CT scanning to characterize the microstructural development of three distinct igneous rock types. Laboratory measurements were then performed to determine the density, porosity, permeability, and compressional and shear wave travel times of the rock cores in both dry and water-saturated states. The results show that water content significantly affects the waveforms in both the time and frequency domains. For rocks with developed pores and fractures, the propagation of seismic wave energy is impeded under water-saturated conditions, causing faster attenuation of ultrasonic waves while high-frequency components are retained. For dense rocks, the amplitude of the initial wave segment decreases, the middle-segment amplitude increases, and the tail wave undergoes significant attenuation under saturated conditions, with frequency components in the 50–100 kHz range being filtered out. Furthermore, higher water content leads to lower shear-wave amplitudes and more severe attenuation. These findings contribute to the proper use of acoustic logging data for understanding the microstructure and water content characteristics of igneous rock reservoirs. Full article