Search Results (4,930)

Owing to their breathability, flexibility, washability, and wearability, fabric-based wearable heaters have gained significant attention for personal thermal management and thermotherapy applications. A key challenge, however, lies in achieving high electrical conductivity without compromising the inherent fabric properties or electrothermal performance. To address this, we applied a surface engineering strategy by weaving polyester (PET) warp yarns with carbon nanotube-wrapped cotton weft yarns (CCY) to construct a conductive blended fabric. The CCY was prepared through a facile surface wrapping process, creating a conductive layer on the cotton yarns. The resulting PET/CCY fabric exhibited excellent breathability, with air permeability of 1104.09 ± 7.69 mm s⁻¹ and moisture permeability of 2536.67 ± 25.45 g m⁻² day⁻¹. It also demonstrated superior electrothermal performance, including a rapid response time (45 s), low driving voltage (1–7 V), uniform temperature distribution, and reliable stability. Remarkably, the fabric maintained consistent performance after 5000 bending cycles, 500 folding cycles, 60 washing cycles, and 12 weeks of atmospheric exposure, highlighting its flexibility, washability, and long-term durability. These comprehensive properties position the PET/CCY blended fabric as a promising high-performance wearable heater for advanced personal thermal management and thermotherapy applications. Full article

Electrokinetic (EK) remediation improves contaminant transport in low-permeability soils, but persistent electric fields degrade the soil electrochemical habitat, reducing treatment efficiency. Combining EK with plants may mitigate this deterioration, yet plant selection criteria remain unclear. This study screened tall fescue (Festuca arundinacea), ryegrass (Lolium perenne), corn grass (Zea mexicana (Schrad.) Kuntze), and alfalfa (Medicago sativa) in 60-day EK-assisted remediation of petroleum-contaminated silty clay under periodically reversed polarity. Petroleum removal, current dynamics, and soil physicochemical and biological indicators were monitored. Tall fescue performed best, achieving the highest petroleum removal (20.21%), greatest electrical conductivity, dissolved organic carbon, and field water-holding capacity, and the largest microbial abundance and dehydrogenase activity. Ryegrass performed similarly. Corn grass showed the tallest shoots but ranked third; alfalfa was least effective. Enhancement beyond simple additivity was species-dependent, observed only for tall fescue and ryegrass. Root-length stimulation correlated with remediation performance, while shoot-height response did not. Plants that mitigated electrochemical deterioration and sustained rhizosphere microbial activity were most suitable. Tall fescue is recommended, with ryegrass as a strong competitor. This study provides a transparent multi-indicator screening framework for selecting plants in EK-phytoremediation systems. Full article

This review analyzes recent advances in fluxgate magnetometers. It introduces an innovative concept of using magnetically ordered composite and crystalline structures made of ferrites or conducting ferromagnetic materials as fluxgate cores. These active physical media enable new multifactor excitation methods, qualitatively improving output parameters. Unlike conventional approaches restricted to magnetic permeability modulation, the authors theoretically justify processes based on the interplay of five physical factors: indirect exchange, magnetostriction, dynamic inhomogeneities, magnetoelectric interaction, and chirality. This paper systematizes original patented modulator designs. These include electrodynamic modulators implemented as compact resonant C antennas and devices utilizing the acoustic magnetoelastic effect, local magnetic inhomogeneities, or electromagnetic-acoustic excitation. Furthermore, the hardware implementation of a specialized two-component fluxgate magnetometer is considered. This device provides high-precision measurements of geomagnetic field parameters for shallow geophysical exploration and navigation systems. Experimental data confirm a significant increase in sensitivity, interference immunity, and transformation precision under extremely low power consumption. This review establishes a solid foundation for a promising applied direction at the intersection of metrology and spintronics. Full article

Bedding planes widely exist in stratified reservoirs and strongly restrict the vertical cross-layer growth of hydraulic fractures. Traditional displacement discontinuity method (DDM) tends to produce spurious negative apertures for compressed weak bedding interfaces and neglects multi-cluster stress superposition in inclined formations. This work proposes an improved DDM incorporating bedding-plane normal-tangential support-stiffness contact constraints together with Mohr–Coulomb-based opening-slip-closure discrimination, which removes non-physical negative-aperture artifacts of closed weak interfaces. The proposed numerical framework is adopted to model fracture initiation, propagation and bedding-interface penetration under multi-fracture interference. Key coupled influences of net pressure, bedding-plane dip angle and fracture-cluster number are quantitatively investigated. Numerical simulations reveal that higher net pressure enhances the lasting cross-layer propagation capacity of hydraulic fractures. Among the examined cases, a bedding dip angle of 60° facilitates fracture penetration through interfaces. Bedding features amplify inter-cluster mechanical interference and lead to asymmetric fracture evolution, tip arrest and interface-parallel fracture propagation, which becomes more pronounced as the number of fracture clusters increases. This study provides theoretical references for multi-cluster fracturing design in low-permeability layered reservoirs. Full article

Accurately characterizing the utilization state of shale oil reservoirs is important for understanding post-development hydrocarbon occurrence and remaining oil potential. This study investigated mudstone–shale reservoirs from the Chang 6₃ to Chang 7₃ intervals of Well Y1 in the Ordos Basin, with Chang 7₂ representing the principal fractured target. A total of 27 samples were analyzed by Rock-Eval pyrolysis, 24 by saturated-hydrocarbon GC–MS, and 22 by pore-structure characterization. These data were integrated with logging-interpreted hydrocarbon saturation and statistical analyses to evaluate development-associated geochemical responses. Relative to Chang 7₃, Chang 7₂ exhibits a distinct molecular-compositional pattern, characterized by an increase in the mean Pr/nC₁₇ ratio from 0.190 to 0.320 and a decrease in the mean ΣC₂₀₋/ΣC₂₁₊ ratio from 2.477 to 1.416, together with corresponding variations in terpane and sterane assemblages. These characteristics are consistent with selective mobilization and redistribution of hydrocarbon components during development. Pyrolysis parameters, logging-interpreted saturation, and sealed-core comparisons are further consistent with a preferential development response in Chang 7₂ while indicating that a substantial residual oil-bearing basis was retained. Its relatively large macropore and total pore volumes and low D2 value provide favorable pore-scale conditions for the potential mobility of movable oil, whereas the more complex smaller-pore system favors retention of less-mobile hydrocarbons. The results clarify the geochemical response characteristics and pore-scale controls of shale-oil utilization in the Chang 7 Member, providing geochemical constraints on the post-development utilization state and remaining-oil potential. Overall, the combined evidence supports a qualitative interpretation that Chang 7₂ underwent preferential and selective utilization while retaining a substantial residual oil-bearing basis. Full article

Tectonic deformation can reorganize adsorption-related pores, matrix pore space, and pore-throat-fracture networks, but how these functional domains jointly govern fluid mobility and permeability stability under stress remains unclear where deformation intensity and coal rank covary. We investigated the B4 coal seam along the Qujiang-Shangzhuang-Yuancun transect in the western Pingxiang-Leping Depression Belt using a combination of field-emission scanning electron microscopy (FE-SEM), low-pressure CO₂ adsorption, low-temperature N₂ adsorption, mercury intrusion porosimetry (MIP), nuclear magnetic resonance (NMR), methane adsorption, and N₂ gas-permeability stress-sensitivity tests. Along the transect, coal-body structure changed from primary-structure and cataclastic coal to granulated and mylonitic coal within a regional context of increasing coal rank, decreasing volatile-matter content, and fewer open fractures. Despite comparable Langmuir volumes (16.29–19.96 cm³ g⁻¹), transport-related properties differed markedly. Qujiang samples contained 23.48–30.04% of their method-accessible pore volume in the >100 nm interval and had movable-fluid saturations of 44.7–53.1%. Shangzhuang samples exhibited irreversible N₂ gas-permeability damage of 98.63–99.99%, whereas the Yuancun sample contained abundant method-accessible pore volume across all operational size intervals but had a movable-fluid saturation of only 19.21%. Thus, accessible pore volume does not necessarily correspond to connected, stress-stable transport pathways. Favorable coalbed methane intervals require sufficient adsorption-storage space combined with connected, mechanically stable pore-throat-fracture networks. Full article

Solute transport in rough fractures is governed by surface geometry, shear-induced aperture redistribution, and hydraulic conditions. This study presents a comparative three-dimensional numerical investigation of conservative solute transport in three individual self-affine fracture realizations with JRC values of 9.43, 13.18, and 17.37, five prescribed shear displacements (Us = 1–5 mm), and seven Peclet numbers (Pe = 0.1–1500), yielding 105 finite-element cases. For the selected realizations, increasing roughness and shear displacement reorganized the aperture field, enhanced streamline tortuosity, and increased flow heterogeneity, particularly in the medium- and high-roughness geometries. Under the investigated low-Reynolds-number conditions, the pressure-gradient-flow-rate relationships remained approximately linear. Mechanical aperture, hydraulic aperture, and intrinsic permeability evolved asynchronously: hydraulic transport capacity remained nearly stable in the low-roughness realization but decreased progressively in the medium- and high-roughness realizations. Pe primarily controlled the breakthrough regime. Diffusion dominated at Pe = 0.1, mixed advection-diffusion behavior occurred at Pe = 1–10, and advection dominated at Pe ≥ 100. Increasing shear displacement mainly affected the early and late portions of the breakthrough curves, whereas the central transition changed comparatively little. At high roughness and high Pe, concentration isosurfaces showed stronger preferential transport and delayed migration in low-velocity or weakly connected regions. The resulting apparent local retention denotes transient storage and delayed exchange within the fracture void space. No independent experimental validation, multilevel mesh-convergence test, stochastic ensemble analysis, systematic parameter-sensitivity analysis, or breakthrough-curve-derived residence-time, dispersivity, tailing, or transport-aperture metrics were performed. The findings should therefore be interpreted as comparative trends for the three investigated rigid-wall, isolated-fracture, steady-flow, and conservative-transport models, rather than as statistically representative JRC-class relationships or field-scale predictions. Full article

Underground coal fires in steeply inclined extra-thick coal seams evolve through coupled coal–oxygen reaction, gas seepage, heat and species transport, and thermo-mechanical fracture. Taking the Laojunmiao SA7 coal-fire area in Xinjiang, China, as a representative case, this study develops a sequential COMSOL–Abaqus coupling framework to investigate seepage-controlled thermal migration, thermally induced fracture development, and fracture feedback. The transient temperature field calculated in COMSOL is mapped to Abaqus to obtain displacement, stress, and cohesive damage; dominant fracture zones are then reconstructed as preferential transport pathways for re-propagation analysis. Increasing inlet seepage velocity from 0.001 to 0.003 m/s raises the simulated peak temperature at 1000 d from approximately 635 to 1050 K and enlarges the CO₂ migration range. Thermal stress and fracture damage preferentially develop along goaf boundaries and coal–rock interfaces, with broader damage and stronger local connectivity at higher seepage velocity. After fracture reconstruction, fractures mainly promote smoke exhaust and heat dissipation at low seepage velocity but form coupled oxygen-supply, heat-transfer, and product-discharge pathways at high seepage velocity. The results reveal a staged mechanism of seepage-controlled combustion, thermally induced cracking, fracture-enhanced permeability, and amplified re-propagation. Full article

Tidal influence is a well-known phenomenon in the hydrogeology of coastal areas, as it is transmitted through aquifers connected to the sea, generating periodic fluctuations in borehole piezometric levels. The analysis of these fluctuations makes it possible to assess subsurface properties and derive characteristic parameters from the transmission of the pressure wave. Tidal influence results from a complex combination of the gravitational attraction exerted by the Sun and the Moon on the oceanic water mass, the tidal distribution conditioned by ocean morphology, and variable meteorological effects that may be highly localised. The combination of these factors generates oscillations ranging in magnitude from metres to centimetres. Under certain circumstances, such as spring tides coinciding with low atmospheric pressure, these oscillations may cause flooding and other undesirable effects in sensitive areas. The effect of earth tides in inland areas disconnected from the sea, sometimes at high elevations, is also well known and has received increasing scientific attention. Tidal oscillations, which are readily apparent in coastal areas, can also be recorded in certain geological materials, producing fluctuations that can be detected using high-precision sensors. These oscillations are caused by the same gravitational attraction responsible for ocean tides; however, in this case, the gravitational forcing acts on the geological formation itself, giving rise to what is known as an Earth tide or astronomical tide. Recent technological advances have facilitated the detection of these phenomena, which were previously difficult to identify. This study analyses the astronomical influence detected in areas clearly isolated from the sea, focusing on small, low-permeability aquifers where direct gravitational forcing of the groundwater mass cannot account for the observed response. Instead, astronomical forcing acts on the rock mass and indirectly affects piezometric levels. The selected experimental site comprises variable lithologies and different degrees of aquifer confinement and includes numerous research boreholes. It therefore provides an optimal setting for analysing the relationship between lithology and astronomical influence and may serve as a basis for future research in different hydrogeological settings. Full article

The Japanese Garden of La Paz, Bolivia, is a sociocultural space with high biodiversity, with its lagoon receiving treated effluent from the “Las Cholas” Wastewater Treatment Unit. Preliminary monitoring revealed elevated organic matter concentrations, raising concerns about water quality. This study aimed to design a constructed wetland (CW) to remove organic load and demonstrate its potential as a nature-based solution (NBS) for sustainable management. Physicochemical parameters and the trophic state index were evaluated during the dry and wet seasons. Macrophyte species were identified, and the most suitable species were selected through a systematic literature review considering treatment performance and local availability. The results showed alkaline conditions, low nutrient concentrations, and a mesotrophic trophic status. A total of 139 vascular plant species were recorded, including Cyperus involucratus, Azolla filiculoides, and Eichhornia sp. Cyperus involucratus was selected due to its abundance and reported BOD₅ or COD removal efficiency. The proposed system consists of a horizontal subsurface flow CW incorporating permeable reactive barriers filled with water hyacinth leaves as a biosorbent. A design flow rate of 0.86 m³/day was adopted for the proposed CW, corresponding to a hydraulic retention time (HRT) of 1.68 days and an estimated BOD₅ removal efficiency of 68.54%. Full article

The key to exploiting coalbed methane in soft and low-permeability coal seams by deploying horizontal wells in roof strata lies in whether hydraulic fractures can propagate into the coal seam after initiating from the roof. True triaxial physical simulation experiments based on 15 artificially cast fracturing specimens were conducted to explore how in situ stress regimes, coal–roof interface strength, and roof mechanical properties control cross-layer propagation of hydraulic fractures. Results show that the strike-slip fault stress regime yields the highest cross-layer propagation success rate and the lowest average initiation pressure, followed by the normal fault stress regime, while the reverse fault stress regime significantly restricts vertical propagation of fractures. High-strength coal–roof interfaces can promote vertical fracture propagation and lower the fracture initiation pressure. High-strength roofs facilitate stable vertical fracture extension, while low-strength roofs containing microdefects lead to increased initiation pressure. The three geological factors exert hierarchical coupled control over the fracture propagation: in situ stress determines fracture propagation direction, coal–roof interfaces control fracture branching at stratigraphic interfaces, and roof mechanical properties regulate the complexity of induced fracture networks. To achieve high-quality reservoir stimulation, target zones with strike-slip or normal fault stress regimes, high-strength coal–roof interfaces, and matched roof types should be prioritized. Full article

The water vapor permeability coefficient is a key parameter describing moisture transport in building materials, exerting a crucial influence on their hygrothermal performance and indoor humidity regulation. However, uncertainties remain in existing experimental methods and parameter-correction approaches. In this study, three gypsum-based inorganic materials—gypsum–zeolite (G-Z), gypsum–diatomite (G-D), and gypsum–magnesium aluminum silicate (G-A)—were systematically investigated using the wet-cup method to measure their vapor permeability coefficients. The effects of the average relative humidity (RH) and RH gradient on the measured results were quantitatively analyzed. The water vapor transport characteristics of gypsum-based inorganic mineral materials were also analyzed. The results indicate that the influence of the RH gradient is comparatively minor, whereas the average RH is the dominant factor. Within the average RH range of 22–90%, the vapor permeability coefficients of the three materials exhibit a nonlinear dependence that can be accurately described by a binomial function. In the low-humidity range (RH < 70%), the coefficients remain nearly constant, while in the high-humidity range (RH > 70%), they decrease significantly with increasing RH. Microstructural characterization further reveals that G-Z exhibits a well-developed microporous structure and large specific surface area, leading to high moisture adsorption but low permeability; G-D shows superior permeability due to its well-connected meso-and macroporous channels; and G-A forms a dense interlocking structure with few connected pores, resulting in the highest vapor resistance among the three materials. Full article

Unstable water injection is widely used in low-permeability shale oil reservoirs, but its performance under the combined effects of stress sensitivity and threshold pressure gradient remains uncertain. This study aims to determine how these two mechanisms jointly affect unstable water injection performance and to optimize the switching timing and half-cycle period. Core-scale stress sensitivity and flow experiments were conducted, and the results were incorporated into reservoir simulation using the ROCKTAB and Threshold Pressure keywords in Eclipse, enabling a coupled numerical modeling approach. The simulation results indicate that both stress sensitivity and threshold pressure gradient significantly affect ultimate recovery, with stress sensitivity exerting a considerably greater influence. Among the half-cycle scenarios evaluated, a 15-day half cycle yields the best development performance, and longer half cycles are associated with reduced stimulation effects. Extended shut-in periods cause greater formation pressure fluctuations, which may induce additional stress-sensitive damage and impair well productivity. These findings provide practical guidance for designing unstable water injection strategies in low-permeability shale reservoirs. Among the discrete cases simulated, the optimal timing for switching from continuous to unstable water injection is when the water cut reaches 25%, although this value is case-specific; conversion at water cut beyond this threshold leads to progressively diminished oil response. Full article

The Lower Paleozoic carbonate reservoirs in the Yan’an Gas Field are characterized by low porosity, low permeability, and strong heterogeneity, which make effective stimulation difficult. Although supercritical CO₂ (SC-CO₂) acidizing has shown promising results in field applications, the effects of SC-CO₂ concentration and acid type on the pore structure evolution of tight carbonate rocks remain poorly understood. In this study, matrix acidizing experiments were conducted using SC-CO₂+acid multi-component fluids, and nuclear magnetic resonance (NMR) together with porosity–permeability measurements were employed to characterize the changes in pore structure before and after acidizing. The results indicate that compared with a single acid injection, SC-CO₂+acid combined acidizing significantly improves core porosity and permeability. It promotes the dissolution and expansion of small and medium pores, enhances the connectivity of isolated pores, and increases the proportion of medium and large pores along with pore connectivity. SC-CO₂ concentration is a key influencing factor: higher concentrations result in stronger dissolution and greater improvements in porosity and permeability. The acidizing effect of gelled acid mixed with SC-CO₂ is superior to that of regular acid, attributed to the higher viscosity of gelled acid, which prolongs the acid–rock reaction time, enabling more uniform and sufficient dissolution and thus more significant improvements in pore structure and acid flow capacity. This research provides valuable guidance for the design of SC-CO₂ acidizing treatments in carbonate reservoirs. Full article

Hydrogen peroxide (H₂O₂) contributes to oxidative stress in Alzheimer’s disease (AD), yet conventional antioxidants that directly scavenge H₂O₂ have shown limited therapeutic efficacy. Here, we investigated K34 (3,3″-dihydroxy-6′-desmethyl terphenyllin), a catechol-bearing para-terphenyl isolated from the marine fungus Penicillium janthinellum 168CLC-17.1, as an indirect H₂O₂-decomposing agent. Complementary cell-free assays showed that K34 promoted peroxidase-dependent H₂O₂ decomposition, including Hb-supported H₂O₂ decomposition, while molecular docking predicted a plausible binding pose near the Hbβ heme pocket. In amyloid-β₄₂ (Aβ₄₂)-stimulated primary astrocytes, K34 reduced intracellular H₂O₂. In APPswe/PSEN1dE9 (APP/PS1) mice subjected to focal GFAP-inducible diphtheria toxin receptor (fGiD), systemic K34 attenuated memory impairment, preserved NeuN-positive neurons, reduced GFAP immunoreactivity, and improved hippocampal spike probability. K34 also exhibited low passive blood–brain barrier (BBB) permeability and limited inhibition of five major cytochrome P450 (CYP) isoforms under the tested conditions. These findings extend Hb-supported H₂O₂ decomposition to a structurally distinct marine natural product and support further evaluation of K34 as an antioxidant scaffold for modulating oxidative stress-associated neurodegenerative phenotypes. Full article