Search Results (11,396)

Soil aeration is a widely used field method to remove subsurface methane (CH₄) following natural gas (NG) pipeline leaks, reducing safety risks and enabling site recovery. However, conventional aeration practices often rely on generalized guidance and do not explicitly account for site-specific soil conditions, resulting in inefficient CH₄ removal and prolonged cleanup times. This study investigated the influence of soil properties and aeration system design on CH₄ removal using controlled field-scale experiments and a validated multiphase transport model. Six field-scale aeration experiments and 39 numerical simulations were conducted across representative soil types, soil moisture conditions, vacuum pressures, and bar hole configurations. Results show that CH₄ removal occurs in two distinct stages: an initial advection-dominated removal phase followed by a slower diffusion-controlled phase. More than 50% of the residual CH₄ mass was removed within the first 10 min of aeration in permeable soils, while greater than 90% removal was achieved within 30 min under favorable conditions. Increasing vacuum pressure improved CH₄ removal by approximately 15 percentage points after 60 min and increased the effective radius of influence of individual bar holes. Soil permeability exerted a primary control on performance, with high-permeability soils exhibiting substantially faster CH₄ removal and larger treatment zones than lower-permeability soils. Bar hole configuration was equally important; properly spaced bar holes improved plume coverage and removal efficiency, whereas excessive overlap reduced aeration effectiveness through airflow interference. Overall, the results demonstrate that CH₄ removal during NG soil aeration is governed by coupled interactions among soil properties, moisture conditions, vacuum pressure, and bar hole deployment. Incorporating these factors into aeration system design can improve removal efficiency, reduce aeration duration, and provide utilities with a quantitative basis for safer and more effective NG leak mitigation. Full article

Two-dimensional transient electroluminescent devices have attracted considerable attention owing to their simple device architecture and reduced contact-barrier dependence. However, the influence of semiconductor transport polarity on transient electroluminescence (EL) remains unclear. Here, we compare four representative transition metal dichalcogenide (TMDC) semiconductors with different transport polarities and find that ambipolar WSe₂ exhibits a stronger transient EL signal under identical driving conditions, a trend that cannot be explained by relative photoluminescence quantum yield (PLQY) alone. Transfer characteristics and gate-modulated photoluminescence (PL) measurements were further used to analyze the gate-dependent carrier doping states and the local spectral response associated with interfacial carrier modulation near the metal/TMDC interface during abrupt gate-voltage switching. Based on these results, we propose a possible physical picture in which ambipolar WSe₂ is more likely to form a transient interfacial electron–hole distribution favorable for electron–hole radiative recombination, whereas predominantly n-type materials tend to form electron-rich interfacial carrier states. These findings suggest that semiconductor transport polarity is an important material factor for designing low-dimensional transient electroluminescent devices. Full article

This work presents an automated vision-based measurement system designed for the precise dimensional characterization of high-aspect-ratio micro-holes, achieving a relative dimensional error of less than 1% for characterizing high-aspect-ratio damage geometries. The system integrates coaxial microscopic imaging with a precision motorized scanning stage. To ensure high-fidelity measurements in early-stage warning applications, depth is determined using a focus variation method driven by a robust data fusion strategy. By capturing a sequence of images along the Z-axis, the focal planes of the defect’s surface orifice and internal base are automatically identified using a data fusion algorithm based on a consensus evaluation of three parallel sharpness metrics (Tenengrad, Laplacian, and Brenner variants). The Z-axis scanning module, featuring encoder feedback and bi-directional compensation, achieves a repeated positioning error of ±0.5 µm. For lateral damage assessment, the system’s high magnification provides an effective sampling resolution of 0.09 µm. The equivalent diameter of the focused orifice image is calculated through a robust pipeline involving adaptive thresholding, morphological filtering, and sub-pixel ellipse fitting, which serves as a highly sensitive indicator for early-stage structural deformation. The entire process can be completed within five minutes, demonstrating a rapid, highly accurate, and localized optical inspection solution that generates high-precision dimensional data crucial for quality inspection in aerospace and precision engineering. Full article

The Z-scheme Ag₂MoO₄/BiOCl heterojunction with oxygen vacancies was successfully fabricated at a low temperature via a simple in situ precipitation method. The morphological, structural, and optical characteristics of the Ag₂MoO₄/BiOCl heterojunction were systematically examined. The optimized synthesized Ag₂MoO₄/BiOCl heterojunction achieved a removal rate of 80.44% for ciprofloxacin within 180 min of simulated solar irradiation, which was 3.27 and 1.90 times higher than that of pure Ag₂MoO₄ and BiOCl, respectively. The fabricated Z-scheme heterojunction and oxygen vacancies optimize the electron transfer route, enhancing the separation efficiency of photogenerated electrons and holes. Moreover, the active species trapping experiments and ESR analyses demonstrated that holes were the primary reactive species involved in the photocatalytic process. It was hypothesized that the Ag₂MoO₄/BiOCl heterojunction adhered to a Z-scheme mechanism for charge transfer. The straightforward approach opened up novel avenues for the synthesis of efficient BiOCl-based photocatalysts aimed at environmental remediation. Full article

Numerous attempts have been made to detect signs of ozone layer recovery over Antarctica, which has been expected since the beginning of the 21st century as a result of the reduction in concentrations of ozone-depleting substances in the Antarctic stratosphere, in accordance with the provisions of the 1987 Montreal Protocol and subsequent amendments aimed at protecting the ozone layer. Large year-to-year variability in the Antarctic ozone, driven by changes in atmospheric dynamics, has made it difficult to draw definitive conclusions about the rate of Antarctic ozone recovery. In this paper, we present an alternative approach to analyse ozone recovery by examining patterns in blue–red heatmaps of total ozone column (TOC) trends during the winter–spring period from 1980 to 2025. Three annual TOC time series (winter average, 15 September value, and spring minimum) were analysed to monitor the ozone hole development over the Syowa and Amundsen–Scott stations. Various sources of the daily TOC data were examined, including reanalysis data, ground-based measurements, and satellite observations. Regardless of the data source, we found that, for both stations, blue cells (negative trends) dominated in the areas of the heatmap where the TOC trends ended before 2000, while red cells (positive trends) appeared mostly afterwards. These results confirm the hypothesis of a trend reversal, i.e., a recovery beginning in the early 2000s, which was obscured in the original, noisy TOC time series. Full article

To address the inherent conflict between fluidity and stability in high-concentration unclassified tailings slurries for blasthole stemming slurry (BSS), this study establishes an evaluation system based on “equal fluidity” to screen and optimize chemical admixtures suitable for high-concentration BSS. Three typical superplasticizers—polycarboxylate (PCE), naphthalene-based (NF), and melamine-based (MF)—were selected to systematically compare their effects on rheological parameters and bleeding performance under a controlled, consistent fluidity condition (16.0 ± 0.5 cm). The results indicate that the effectiveness of superplasticizers exhibits noticeably concentration dependence. While NF demonstrates the highest dispersion efficiency at low concentrations, PCE emerges as the sole effective admixture capable of maintaining the fluidity of high-concentration BSS (71% solid mass fraction), attributed to its robust steric hindrance effect. Rheological analysis reveals that the PCE-modified BSS exhibits a unique state characterized by “low yield stress and high differential viscosity,” which effectively decouples the contradiction between macroscopic flow and microscopic stability. Furthermore, the synergistic effect of high concentration and PCE constructs a kinetically stable suspension system, achieving “zero bleeding.” This study confirms that PCE is the optimal choice for preparing high-concentration pumpable BSS, providing a theoretical foundation for the design of deep-hole stemming materials in mining engineering. Full article

Bone healing is a complex regenerative process regulated by interactions between skeletal and host biologic responses, and failure of bone repair remains a major challenge in orthopedic surgery. Using a murine model, this study investigated whether a preemptive priming stimulus could enhance healing of a subsequent contralateral cortical bone defect and whether the type and timing of the stimulus influenced this response. Skeletally mature male mice were randomized into six groups (n = 6/group) receiving either no stimulus, a skin incision, skin and muscle incisions, or a unicortical femoral drill hole stimulus. A subcritical-sized 1 mm × 2 mm unicortical defect was subsequently created in the contralateral femur after intervals of 2, 6, or 12 weeks, depending on group allocation. Femora were harvested 8 weeks later for micro-computed tomography, histology, and immunofluorescence analyses. Mice undergoing muscle elevation 2 weeks prior to defect creation and mice receiving drill hole stimulus 12 weeks prior demonstrated the greatest degree of cortical regeneration and healing of the contralateral subcritical-sized defect, with normalized cortical thicknesses reaching 104% and 109% of adjacent native cortex, respectively. Histologic analysis confirmed restoration of mature cortical architecture in these groups. Immunofluorescence analysis demonstrated a relative shift toward an Arg1-associated reparative macrophage profile with reduced iNOS-associated inflammatory signaling, suggesting that modulation of the innate immune response contributed to the enhanced regenerative healing observed. These findings demonstrate that priming stimuli can enhance subsequent bone healing in a timing- and stimulus-dependent manner and may represent a novel strategy to optimize bone regeneration. Full article

In this study, previously selected lactic acid bacteria (LAB)—Leuconostoc mesenteroides, Lacticaseibacillus paracasei, and Loigolactobacillus coryniformis—as well as kefir ferment were evaluated as adjunct cultures in pasteurized goat’s milk cheese. Microbiological and physicochemical attributes of cheese treatments were characterized during the 60-day maturation period, whereas texture profile, proximate composition, and sensory analysis were carried out in the final product. Mesophiles and LAB remained high (>8 log₁₀ CFU/g) throughout maturation, whereas the control exhibited significantly lower counts (~7 log₁₀ CFU/g; p < 0.001). For Staphylococcus aureus, the most pronounced reductions occurred in kefir > L. mesenteroides > LAB cocktail, with final counts of 3.67 ± 0.241, 4.26 ± 0.241, and 4.36 ± 0.241 log₁₀ CFU/g, respectively. Cheeses containing adjunct cultures exhibited higher titratable acidity (up to 0.1971 ± 0.0180 g lactic acid/kg cheese) and lower pH (5.41 ± 0.0526), indicating a quicker acidification process during ripening. Kefir > L. mesenteroides > LAB cocktail cheeses achieved the highest overall acceptance scores (9.15 ± 0.285, 8.44 ± 0.285, and 8.39 ± 0.285, respectively), being characterized by perceivably less holes, softer, less crumbly, and non-rubbery texture. Incorporation of kefir and selected LAB strains can be considered as effective functional adjunct cultures for artisanal goat cheese production. Full article

Additively manufactured composite architected discs offer a potential route for producing lightweight semi-finished blanks that can subsequently be shaped by conventional forming processes. However, the relationship between infill architecture, feature size, and deep-drawing formability remains poorly understood. This study investigates the deep-drawing response of material-extruded short-fibre-reinforced polymer composite discs by combining experimental tests and finite element simulations. Four infill strategies, namely perforated body, re-entrant, square and triangular, were first compared at drawing depths of 10 and 20 mm. The perforated body and re-entrant geometries were successfully formed at 10 mm, whereas only the perforated body withstood 20 mm without macroscopic failure. A second campaign focused on perforated discs with hole diameters of 2.5, 5, 7.5 and 10 mm. All configurations were drawable at 10 mm, while the 2.5 mm case failed at 20 mm. Statistical analysis confirmed that hole diameter significantly affected both retained cup height and side-hole aspect ratio. At 20 mm, larger holes reduced local ovalization but increased elastic recovery, leading to lower retained cup height. FEM simulations were used as an interpretative first-order model. They supported the experimental trends by comparing deformation modes, tensile/compressive stress redistribution, forming energy and strain localization. The results show that the formability of architected composite blanks is governed not only by material volume or porosity but by the ability of the internal architecture to accommodate deformation through a suitable balance between local stiffness and geometric compliance. These findings provide design-oriented guidelines for the development of additively manufactured architected blanks intended for hybrid additive–forming manufacturing routes. Full article

In recent decades, numerical methods have become indispensable tools for solving complex problems in science and engineering. Among these, the finite element method (FEM) is widely recognized as a powerful computational approach. However, traditional FEM has significant limitations when modeling discontinuities such as cracks, holes, or material interfaces, particularly in functionally graded materials (FGMs). To address these challenges, this study proposes an advanced framework that integrates the Extended Finite Element Method (XFEM) with Isogeometric Analysis (XIGA), referred to as XFEM–XIGA, to simulate stress concentration factors (SCFs) around circular holes in both isotropic and FGM plates. The proposed methodology employs the level-set method to represent discontinuous boundaries and incorporates appropriate enrichment functions into the displacement field, allowing accurate modeling of stress concentrations without the need for remeshing. MATLAB codes were developed to implement this integration, providing a flexible computational platform for practical engineering applications. The performance of the proposed XFEM–XIGA approach was evaluated using several benchmark problems, including isotropic plates with circular holes near material boundaries and FGMs subjected to uniaxial tensile loading. The results obtained from the XFEM–XIGA model were compared with analytical solutions, standard FEM results, and available experimental data. For isotropic plates, the XFEM–XIGA model achieved a stress concentration error of 1.71%. For FGM plates with cracks or circular holes, the error was 2.55% compared with exact solutions. These findings demonstrate the robustness and accuracy of the integrated method in handling complex geometries and heterogeneous material properties. Overall, this study shows that the combination of XFEM and XIGA offers an efficient and reliable tool for analyzing stress concentration factors in FGM structures. The proposed approach provides improved modeling capabilities for industrial components where stress concentrations at material boundaries are critical to structural integrity and performance. Full article

To overcome the limitations of single-dimensional data and low efficiency in traditional cycloidal gear inspection, a comprehensive machine vision-based method was proposed. A high-precision vision platform was established, and a Sigmoid surface-based edge detection algorithm was employed for sub-pixel edge localization. Logarithmic transformation combined with light intensity compensation was applied to correct saturation-induced errors. The pixel equivalent and compensation coefficient were systematically calibrated using a dot-matrix plate and gauge blocks. A sub-pixel tooth profile model in the physical coordinate system was reconstructed through pixel equivalent calibration, dynamic light intensity compensation, and multi-coordinate transformation. Comparative tests against a coordinate measuring machine (CMM) verified that the point-to-point deviation between the two measurement systems was within 10 μm (maximum 11.62 μm). The inherent tooth profile deviation of the tested cycloidal gears, which reflects the machining quality of workpieces, ranged from 24 μm to 37 μm. Multiple repeated tests prove that the system achieves a repeat positioning accuracy of 0.8 μm. Based on the measurement characteristics, a hybrid analytical method integrating Cartesian and polar coordinate systems was developed, enabling the simultaneous evaluation of critical geometric tolerances, such as the diameters of the center hole and crankshaft hole. The full inspection cycle for cycloidal gears was reduced to 13 s, which demonstrates a substantial efficiency improvement over traditional methods. Full article

Geodiversity, particularly topographical gradients, significantly influences ecosystem function by creating heterogeneous environmental conditions. This study examined how local-scale microtopography and litter bag perforation affected leaf litter decomposition rates in a humid-temperate secondary forest. We categorized microtopography into ridge, valley, southwest slope, and northeast slope, with relative height differences of around 20 m. Using the litter bag method comparing non-perforated (1 mm mesh) and perforated (with 6 mm holes) bags, we measured leaf litter mass loss and moisture content of Quercus serrata over 6 and 12 months. While microtopography caused only slight differences in leaf litter moisture content, it significantly influenced decomposition rates. Leaf litter mass loss was lower in valley microtopography compared to the southwest slope and ridge microtopography. We infer that topographical differences in unmeasured microclimatic factors, such as solar radiation and soil temperature, may have potentially driven these spatial variations in decomposition. Furthermore, because the litter bag perforation did not significantly promote further mass loss, our results suggest that baseline decomposition driven by organisms capable of passing through the 1 mm mesh (e.g., microbes and meso/microfauna) might have been sufficiently high in this environment. These findings highlight that local-scale microtopographical differences enhance the spatial heterogeneity of leaf litter decomposition in forest ecosystems. Full article

The nucleophilic properties of the isolated dicyanoaurate(I) anion in σ-hole interactions were investigated using theoretical calculations of models from 19 crystalline literature structures. The study focuses on the ability of [Au(CN)₂]⁻ to participate in various noncovalent interactions, including halogen, chalcogen, pnictogen, and tetrel bonds. The research reveals that both nitrogen atoms of the cyanide ligands and the gold(I) center exhibit nucleophilic behavior. The nature of all interactions and philicities of interacting atoms were confirmed using a set of theoretical methods, including QTAIM topological analysis, noncovalent interaction plots (NCIplot), electrostatic potential (ESP) surfaces, electron localization function (ELF), analysis of electron density (ED), and electrostatic potential (ESP) minima in their 1D profiles along the bond paths, BSSE corrected dimerization energies, and NBO charge-transfer analysis. The study demonstrates that the dicyanoaurate(I) anion can act as a versatile building block in supramolecular chemistry, participating in multiple types of noncovalent interactions through different sites, including first confirmed examples of gold(I)-involving intermolecular chalcogen bonds. Full article

Clustering is the process in Wireless Sensor Networks (WSNs) used to make the routing process efficient and for selecting the optimized path for sending the data, considering metrics like energy consumption and node distance. Many clustering routing algorithms are addressed for selecting the best path. Among them, Progressive Index Modulation in Intra cluster and Inter cluster routing algorithms uses the index shifting technique for distributing the cluster head role among the sensor nodes. Because of static node deployment, WSN causes the energy hole formation. Hence, this manuscript proposes an Equiangular Wedge Energy Hole Detection (EWED) algorithm for multi-hop WSNs to detect and prevent energy holes. In the hole detection phase, the network region is split into equiangular wedges, where each node serves as a generating point in the geometry to create a Region of Interest (ROI). Finally, the simulation results reveal that the EWED achieves higher network performance compared to the existing clustering routing algorithms. Full article

Ribonucleotides are frequently incorporated into DNA during the replication of genetic information and, if missed during ribonucleotide excision repair, they may undergo phosphodiester bond rearrangement or cleavage. These changes can in turn lead to deformation of the spatial geometry of the local double helix and potentially interfere with charge transfer through ds-DNA. This process is believed to support long-range communication between proteins involved in genome replication and repair. This study theoretically explores how a single embedded riboadenosine (A₃) affects the structure, electronic properties, and charge-transfer properties of double-stranded DNA ([A₁G₂A₃G₄A₅]*[T₅C₄T₃C₂T₁]). In particular, the study focuses on four products formed at the ribonucleotide site: native 3′,5′-linkage (R-DNA), the 2′,3′-cyclic phosphate intermediate (IM-R-DNA), rearranged 2′,5-linked (RE-R-DNA), and the single-strand-break cleavage product (SSB-R-DNA). This theoretical investigation was performed at the M06-2X/6-31++G**//M06-2X/D95** level of theory in the aqueous phase. Significant spatial geometry perturbations were found at the central part of ds-oligonucleotides, i.e., the A₃T₃|G₄C₂ region, where the modified linkage affected the base overlap and stacking interactions most strongly; in the rearranged and cleaved forms, stacking at this site decreased by about 7 kcal•mol⁻¹ relative to native DNA. Global electronic analysis showed that R-DNA had the highest ionisation potential and the lowest electron affinity, whereas SSB-R-DNA displayed the lowest adiabatic ionisation potential and the highest adiabatic electron affinity, indicating a much greater tendency to stabilise excess charge. At the base-pair level, G₂C₄ was usually the preferred hole sink, except in RE-R-DNA, where G₄C₂ was favoured. In contrast, electron localisation was generally favoured at G₄C₂, while, in SSB-R-DNA, the A₃T₃ pair became the most favourable electron-accepting site. Overall, the results show that even a single ribonucleotide, depending on its linkage chemistry, can substantially reshape charge migration through ds-DNA and may therefore influence lesion recognition, repair efficiency, and genome stability. Full article