Gravitational fingering often occurs for water flow in the vadose zone and accurate modeling of this important flow process remains a significant scientific challenge. This paper presents the latest theoretical developments of the optimality-based active region model (ARM), a macroscopic framework developed for describing gravitational fingering flow in the vadose zone. ARM divides the soil into active (fingering) and inactive regions, introducing a relationship between water flux and hydraulic gradient derived from the principle of optimality that the system self-organizes to maximize water flow conductivity. Unlike traditional models, ARM’s hydraulic conductivity depends on both capillary pressure or water saturation and water flux, reflecting the unstable nature of fingering flow. The paper provides an updated mathematical derivation of ARM relationships using calculus of variations and extends ARM to account for small water flux in the non-fingering zone, resulting in a dual-flow field model. These new developments should make ARM more rigorous and realistic for field-scale applications.

Influence of coarse aggregate volume fraction on the fracture process zone in concrete: An integrated experimental and theoretical study

Synergistic toughening effect of coarse aggregate and hybrid steel fibres on the evolution of fracture process zone in UHPC under Mode I crack tip deformation

Oscillatory instabilities of dynamic fractures arise under mode-I loading as the crack velocity approaches or exceeds the Rayleigh wave speed, c_{R}. Anomalously, at velocities far below c_{R}, experiments reveal a distinct quasistatic oscillatory instability in fluid-driven fracturing of porous materials, formed by continuous bifurcations of "daughter cracks." This phenomenon falls outside the applicability of existing fracture theories. Our asymptotic stability analysis of wave-shaped cracks reveals that oscillations originate from the competition between the stabilizing effect of cohesive force in the process zone and the destabilizing effect of shear perturbations along the crack sides. We further derive the characteristic oscillation wavelength and demonstrate that it is jointly governed by the fracture process and fluid invasion. The findings broaden the physical basis of competing mechanisms governing oscillatory fracture instabilities.

ABSTRACT The characteristics of the constitutive behavior of aligned (ASFRC) and ordinary (SFRC) steel fiber–reinforced cementitious composite exert a decisive influence on the fracture performance of the three‐point bending beam specimens. This study established a coupled analytical method by integrating the stochastic fiber bridging curve with the matrix constitutive relation, enabling quantitative characterization of the stochastic fracture behavior and energy dissipation mechanisms of both the matrix and fibers. Through stochastic modeling of the fiber embedment length distribution, the mean value and variance of bridging stress were derived. Subsequently, the effects of specimen size and the initial crack length‐to‐depth ratio ( a 0 / D ) on the fracture process zone (FPZ) and energy dissipation were systematically investigated. The simulation results showed good agreement with the experimental measurements. For ASFRC specimens, the proportion of energy dissipated by steel fiber pullout at peak load ( P max ) was significantly higher than that of SFRC. The energy dissipation U undergoes a transition from a matrix‐dominated mechanism to a fiber‐dominated mechanism. Additionally, the dispersion of energy dissipated by steel fiber pullout in ASFRC specimens was notably smaller than that in SFRC specimens, indicating that the performance fluctuations induced by the stochasticity of fiber orientation were partially mitigated in ASFRC specimens.

The development of agricultural commodity-based tourist areas requires technical planning that considers the physical characteristics of the area, land suitability, and integration with spatial planning policies so that it is sustainable and can be implemented. Petang Village, Badung Regency, has significant cocoa potential, but its use is not spatially directed and risks causing land function conflicts if it is not supported by planning based on technical analysis. This research aims to formulate an integrated cocoa tourism area planning based on spatial analysis and land suitability as the basis for regional development in accordance with the carrying capacity of the environment and regional spatial planning. The research method uses a technical-planning approach through spatial analysis based on geographic information systems by examining the physical parameters of the area including slope slope, altitude, morphology, soil type, rainfall, vulnerability to soil movement, and land cover, combined with the analysis of the suitability of RTRW and RDTR zoning. Data was obtained through secondary data collection, field observation, and thematic mapping of the planning area. The results of the analysis showed that most of the Petang Village area has biophysical characteristics that are suitable for the development of integrated cocoa tourism areas with medium to high levels of land suitability, especially in plantation zones with low to medium slopes, latosol soil types, and low-medium landslide susceptibility. Regional planning results in the division of functional zones that are integrated between cocoa cultivation, educational tourism, yield processing, and environmental buffer zones. The conclusion of the study shows that the spatial analysis and land suitability approach is able to produce more targeted planning of cocoa tourism areas, adaptive to the physical conditions of the region, and supports the development of areas based on sustainability and spatial planning.

To reduce the wireless transmission losses, glass composite vias (used for Radio Frequency Micro Electromechanical system (RF-MEMS)) is a potential alternative. Electrochemical Discharge Machining (ECDM) is an emerging technique for the micro machining of glass composites, but uncontrolled plasma in the processing zone compromises the quality characteristics. Therefore, the present communication has investigated the assistance of rotary magnetic field in ECDM to improve the quality of micro holes, while enhancing the tool wear ratio. A computational modelling of magnetic flux density on gas film formation and the ionization of plasma was performed to analyze the rotary effects. A Thermogravimetric Analysis (TGA) was performed to assess the thermal behaviour of glass epoxy composite, and a Gaussian based computational model of discharge was simulated to understand the material removal mechanism of glass epoxy composite. The present study conjectured that the assistance of rotary magnetic field in ECDM resulted in the reduction of hole deviation and surface roughness of micro holes by 62.31% and 53.63% respectively, while improving the tool wear ratio by 62.5%. Furthermore, the effect of response characteristics was assessed on the Triple Bottom Line (TBL) that indicated sustainability enrichment by virtue of rotary magnetic field. Consequently, the improvement in quality of micromachining along with sustainability enrichment implied the industrial feasibility of glass epoxy composite vias for RF-MEMS.

Experimental investigation on crack propagation and fracture process zone evolution in flame-treated granite

Background: Pneumoconiosis (including silicosis, coal workers’ pneumoconiosis, and asbestosis) remains a major occupational health concern, particularly in settings with sustained exposure to respirable mineral dust. Conventional epidemiological approaches often under-represent spatial heterogeneity in exposure contexts, potentially masking localized disease clusters and delaying targeted prevention. Geographic Information Systems (GIS) and spatial statistics provide a means to integrate georeferenced occupational, environmental, and health data, enabling spatially explicit surveillance and risk assessment. This review provides an overview of GIS applications in pneumoconiosis research and discusses implications for nursing practice and occupational health nursing. Methods: A structured literature search was conducted in Web of Science, Scopus, PubMed, and Google Scholar using combinations of keywords related to pneumoconiosis (e.g., “silicosis”, “coal workers’ pneumoconiosis”, “asbestosis”), GIS (e.g., “geographic information system”, “spatial analysis”), and spatial statistical methods (e.g., “Moran’s I”, “Getis-Ord Gi*”, “kernel density”, “SaTScan”, “spatial regression”, “GWR/MGWR”). Eligible publications included peer-reviewed studies applying GIS/spatial analytics to pneumoconiosis outcomes, exposure assessment, clustering/hotspot detection, or spatial risk modeling. Consistent with the template structure, findings are synthesized into three sections: (i) methods to characterize spatial patterns; (ii) hotspot/cluster analysis approaches; and (iii) spatial regression models to identify risk factors. Results: GIS-enabled mapping and spatial statistics consistently revealed non-random spatial patterns of pneumoconiosis, with clustering frequently aligned with mining, stone processing, construction corridors, and industrial zones. Hotspot methods (e.g., KDE, LISA, Getis-Ord Gi*, scan statistics) were useful in detecting localized high-risk areas for intensified screening and prevention. Spatial regression approaches (e.g., spatial lag/error models, Bayesian CAR, and GWR/MGWR) improved inference by accounting for spatial dependence and local non-stationarity, identifying associations between pneumoconiosis indicators and contextual factors such as industrial density, dust exposure proxies, sociodemographic vulnerability, and access to occupational health services. Nursing-relevant applications include improved surveillance sensitivity, geographically targeted health education, risk communication, and prioritization of screening/referral resources. Conclusions: GIS and spatial statistics strengthen pneumoconiosis research by uncovering spatial inequities in exposure and disease burden and by improving the explanatory power of risk models. For occupational health nursing, spatially informed evidence supports proactive surveillance, targeted interventions, and resource allocation. Future work should prioritize interoperable data pipelines, privacy-preserving geocoding, and capacity building to integrate GIS into routine occupational health nursing practice.

Climate change poses escalating risks to labor-intensive industries in South Asia. This mixed‑methods study assessed how climate‑related hazards affect the health, safety and productivity of workers in Sri Lankan small‑ and medium‑scale apparel manufacturing companies (SMAMCs). A survey of 384 employees in Biyagama and Katunayake Export Processing Zones captured quantitative data on exposure to excessive heat, flooding, indoor air pollution and mosquito‑borne diseases, and elicited qualitative accounts of workplace experiences. Heat waves and high humidity were the most pervasive stressors: 81.25% (95% CI; 77.3 to 85.2) of respondents reported heat stress, with headaches, dehydration, and diminished concentration frequently linked to needle‑prick injuries. Flood events damaged infrastructure and heightened respiratory, gastrointestinal and dermatological illnesses, while inadequate ventilation compounded air‑quality problems; 95% (95% CI; 92.4 to 96.8) of workers complained of persistent coughing. Dengue incidence over the preceding five years reached 10.68% (95% CI; 8.0 to 14.2), reflecting expanding vector habitats. Chi‑square analysis confirmed statistically significant associations between each hazard and adverse health outcomes. The study underscores the need for integrated adaptation measures, improved ventilation, low‑cost cooling, drainage upgrades and systematic vector control, supported by enforceable regulations and targeted financial assistance. Enhancing climate resilience in SMAMCs is essential for safeguarding worker wellbeing and sustaining Sri Lanka’s export competitiveness, while contributing to global goals on decent work and climate action targets.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12889-026-26344-1.

Achieving effective interlayer penetration in stratified reservoirs remains challenging. This study investigates fracture propagation morphology and cross-layer behavior guided by directional perforation parameters. A coupled seepage-stress-damage finite element model, based on volume opening-stress disturbance theory, was developed and validated experimentally, utilizing Grey Relational Analysis for sensitivity. The results indicate that: (1) Increasing the perforation count promotes complex fracture networks and widens the fracture process zone, thereby lowering initiation pressure and enhancing penetration—particularly under low lateral stress and high injection rates. (2) Larger perforation azimuths transition fractures from curved to multi-branch patterns, increasing initiation pressure; conversely, reducing the azimuth under high deviatoric stress improves efficiency. (3) Deeper perforations maintain curved fracture trajectories but widen the fracture process zone and reduce initiation pressure; notably, combining greater depth with high injection rates accelerates initiation. (4) Sensitivity analysis reveals that the lateral stress coefficient dominates fracture width, perforation azimuth controls initiation pressure, while injection rate is the decisive factor for propagation velocity. The novelty of this work lies in elucidating the mechanical mechanisms of cross-layer propagation under coupled multi-physics conditions and providing optimization strategies to enhance gas recovery in layered reservoirs.

The growing global demand for Rare Earth Elements (REEs), essential inputs for the energy transition, is marked by a high geopolitical concentration in the supply chain. In this context, Brazil seeks to position itself as an alternative supplier, facing the historical challenge of vertically integrating its mineral production. This article analyzes the prospective potential of the state of Maranhão to consolidate itself as an integrated industrial hub for rare earth elements (REEs), with a horizon up to 2045. The methodology was based on qualitative document analysis, triangulating data from geological reports, infrastructure and business plans, and national strategic studies. The results identify four main geological axes with potential for REE (Lower Itapecuru, Northwest, East/Southeast, and Southwest/South-Central), rich in minerals such as monazite and xenotime. More crucially, the existence of a mature logistical-industrial advantage is noted, composed of the triad of Itaqui Port, Carajás Railway, and the Bacabeira Export Processing Zone(EPZ), which enables local processing. It is concluded that the unique synergy between geological resources and existing logistical infrastructure offers Maranhão the conditions for the vertical integration of the production chain. The success of this vision, however, is contingent upon overcoming critical challenges, notably the technological mastery of oxide separation metallurgy and the rigorous management of radioactive waste (NORM/TENORM).

This article examines the 2023 Italy–Albania agreement for the construction and operation of offshore Italian migrant detention camps in Albania. Looking at the larger history of colonial relations of power between the two countries, the authors trace how recent migration policies—and the emerging carceral capitalist industry in Albania—are entangled with racial hierarchies of global capitalism. By drawing attention to the Italy–Albania migrant deal, the authors analyze how these outsourcing practices of the European border regime utilize former socialist countries like Albania as zones of migrant detention, processing, and deportation. The authors argue that, through the premise of integration into the EU and the global racial capitalist circuit, candidate countries offer migrant control services in exchange for more favorable labor relations for its own citizens in the EU.

The determination of double-K parameters of concrete components is typically carried out through experimental and analytical methods within the framework of Linear Elastic Fracture Mechanics (LEFM). Testing large-scale concrete components with arbitrary geometry presents significant challenges. These challenges also affect the evaluation of double-K fracture parameters. To address this problem, this paper proposes an alternative numerical approach. The method consists of two main steps and is designed to determine the double-K parameters for large-scale concrete components. Based on known physical properties obtained through material property testing, the numerical results demonstrate good agreement with both analytical solutions and experimental data. In this approach, a solution-based crack propagation path is obtained using an XFEM-cohesive zone model (CZM) analysis. The critical crack opening displacement (w crit ) is employed to discretize the physical crack from the fracture process zone, while simultaneously filtering out the nodes participating crack face regeneration. The resulting physical crack model is then reinserted into the original model to perform a static XFEM crack analysis, yielding the fracture toughness curve and double-K parameters. Fracture energy and specimen thickness are identified as factors influencing w crit . Three-Point-Bending (TPB), Compact-Tension (CT), and semi-circular bending (SCB) specimens are employed to validate the accuracy of the proposed approach and investigate the characteristics of w crit . A tension-shear benchmark test specimen is employed to demonstrate the robustness and functionality of originally developed crack regeneration technique. The proposed method offers an effective approach to determine the double-K parameters and evaluate the stress intensity factors (SIFs) of arbitrarily shaped cracks. All source code is available upon request by contacting the corresponding author.

Abstract Accurate characterization of deformation fields near the shear rupture tip is essential in dynamic friction and earthquake mechanics investigations. Under ultrahigh-speed conditions, the geometric dimensions, distribution of the speckle and illumination intensity in the imaging are key factors that limit the accurate measurement of the deformation fields by digital image correlation. In this study, we propose a novel femtosecond laser-etched speckle fabrication method on transparent PMMA substrates. Integrated with a transmissive optical configuration, the micro-cavities fabricated and precisely filled with black ink yield speckle patterns with controllable size, high stability, excellent repeatability, and exceptional optical contrast under ultrahigh-speed imaging conditions. The transmissive optical configuration significantly enhances illumination efficiency, resolving synchronization challenges inherent in traditional flash illumination systems. Results from different fields of view indicate that accurate strain measurements in the rupture tip singular zone can be achieved at a spatial resolution corresponding to a pixel size of approximately 13.4 µm. Furthermore, when the spatial resolution of speckle images is reduced to 3 µm pixel size, the deformation field within the rupture tip process zone can also be quantified in detail. In summary, the presented method significantly enhances experimental capabilities for studying dynamic rupture with different spatial resolutions. The experimental data will enrich our understanding of dynamic rupture mechanics and laboratory-scale earthquake phenomena.

The paper examines various schemes for grinding flat surfaces of magnetic alloy products with the application of an electric field: schemes for electrochemical and electroabrasive grinding. Based on the analysis of the features of electrochemical grinding (ECG) of planes of cast magnets, it was established that the most preferable process is the simultaneous ECG of planes with current supply through the end surface of the tool electrode (TE) with simultaneous metal removal from the entire surface in the direction of the maintained size with rotation of the grinding part. This method is characterized by the following advantages: the surface being processed is subjected to simultaneous anodic dissolution; the magnets being processed rotate around an axis parallel and eccentrically located relative to the axis of the EI; current supply to the working area is carried out through the end surface of the EI; the feed of the magnets being processed is performed in the direction of the maintained size. Due to such relative movements of the electrodes, a circular washing of non-metallic inclusions with electrolyte occurs, ensuring a circular dissolution of the metal and their removal from the working area, as well as the removal of metal in the direction of the allowance, which is practically equal to the movement of the workpiece. It has been established that it is advisable to perform the shaping of high-precision permanent magnet planes by electroabrasive grinding (EAG) with separation of electrochemical and abrasive processing zones. The EAG process allows increasing productivity, accuracy and quality of processed surfaces in comparison with ECG and can be implemented on a modernized surface grinding machine model 3G71. For various processing schemes, the work specifies achievable indicators and operational features.

Abstract The study aims to investigate the fracture properties of dam‐heel interfaces, which are often weak points in hydraulic structures such as arch dams. The research examines how high‐pressure water exposure influences crack evolution, damage mechanisms, and fracture behavior at concrete‐rock composite interfaces. Specimens were innovatively tested for three‐point bending and four‐point shear after water pressures ranging from 0 to 4 MPa, imitating high dam conditions. Digital image correlation and acoustic emission techniques caught the FPZ evolution process across scales, revealing crack propagation from micro‐crack accumulation to macro‐crack penetration. The study found that initial material degradation from high‐pressure water altered the fracture mode and energy release mechanism. It prevented micro‐crack activity and shear crack formation and shifted the major fracture mechanism from shear to tensile, modifying the crack propagation path and reducing interface fracture toughness. Computational models incorporating the characteristic length and width of the nonlinear fracture process zone revealed a substantial reduction in fracture properties, which increased proportionally with the modal mixing ratio. The findings highlight that high‐pressure water exposure deteriorates the fracture properties at the concrete‐rock interface and corrected the water's impact on FPZ. These insights provide a novel theoretical basis and essential criteria for the safety evaluation of hydraulic engineering while advancing crack resistance design strategies for high dam structures in light of high‐pressure water damage during the design phase.

ABSTRACT This study explores the effects of moisture content and fissure orientation on the mechanical behaviour of fissured coal and the compaction and load-bearing characteristics of fragmented rock, with direct implications for coal mine safety and stability. Uniaxial compression tests, Acoustic Emission (AE) monitoring, and RA-AF parameter analysis were employed to assess fracture development under varying fissure inclinations (0°, 15°, 30°, and 45°) and moisture conditions. The results reveal that coal peak strength decreases at 0° and 15° but increases at 30° and 45°, while the elastic modulus exhibits a consistent upward trend with increasing fissure angles. Moisture content significantly reduces both peak strength and elastic modulus, delays crack initiation, and promotes more extensive crack propagation within the fracture process zone (FPZ), without altering dominant crack modes. In fragmented rock, increased moisture affects compaction behaviour, stress distribution, and deformation patterns, thereby reducing load-bearing capacity. AE b-values and RA-AF trends indicate a shift from shear to tensile failure mechanisms with higher fissure inclinations. FLAC3D numerical simulations corroborated the experimental observations, accurately reproducing crack propagation and FPZ evolution. These findings provide critical insights into moisture-fissure interactions, supporting improved design and stability control strategies for coal pillars and underground mining structures.

The article evaluated the significance of ring structures in the search for mineral resources in the Bokantog area based on remote sensing. Landsat-8 imagery was used to identify circular and arcuate geological structures, and their morphology and relation to lineaments were analyzed. The study results indicated a close association between ring structures and mineralization, particularly gold-sulfide mineralization. Multispectral processing and hydrothermal alteration zone detection algorithms were tested on the Derbez ring structure as a case study. The findings confirm the importance of integrating satellite imagery with geological and geophysical data to enhance exploration efficiency.

The paper considers the problem of constructing safe routes for a group of unmanned aerial vehicles in a limited airspace over an agricultural area. The relevance of the study is due to the growing use of UAV groups in the agro-industrial complex for monitoring, mapping, and processing fields, which requires ensuring flight safety in conditions of high air traffic density, limited communication, and exposure to external factors. A particular challenge is the need for autonomous missions in the presence of navigation errors and natural impacts. A route planning method is proposed based on representing the trajectory of each device as a capsule air corridor – a three-dimensional volume of a fixed radius formed along the trajectory segments. Spatial redundancy ensures safe spacing of trajectories at the planning stage, eliminating conflicts during subsequent autonomous flight operations without the need for continuous coordination between agents. The capsule radius includes a reserve for possible deviations from the planned trajectory, which ensures resistance to navigation errors. The method is based on the sequential formation of routes for each device according to a four-phase scheme, including a vertical ascent from the starting point to the operating altitude, a horizontal transition to the entrance to the processing zone, a return from the exit from the zone to the starting point of the descent, and a vertical descent to the initial position. Each new route is built considering the already reserved air corridors through an analytical check of geometric intersections between the capsules of different trajectories and convex polyhedrons of the processing zones. To improve computational efficiency, hierarchical spatial filtering is used based on bounding parallelepipeds, which allows for the rapid cutting off of obviously non-intersecting objects at the preliminary stage and performing an accurate geometric check only for potentially conflicting route segments. Numerical experiments were carried out for groups of 2 to 32 devices on a typical agricultural plot of one square kilometer. A nonlinear increase in the planning time and the number of iterations with an increase in the number of agents was found, which is due to the need to build each subsequent route in an already partially occupied space with an increasing number of spatial constraints. The length of routes shows a tendency to increase, especially pronounced at the initial stages of scaling, which is associated with the need to bypass already reserved air corridors.