Search Results (4,282)

This study addresses the need for efficient photoelectric materials by fabricating Indium-doped tin sulfide (SnS-In)/titanium dioxide (TiO₂) heterostructure thin films via radio frequency (RF) magnetron sputtering. We systematically investigated the synergistic enhancement of photoelectric properties from both In-doping and the heterostructure design. SnS-In films with controlled In concentrations were prepared by embedding varying numbers of indium pellets into the SnS sputtering target. Our findings reveal that an optimal In doping of 4.93 at% significantly improves the crystalline quality and light absorption of SnS, reducing its band gap from 1.27 eV to 1.13 eV and enhancing carrier concentration and mobility. Subsequently, the optimized SnS-In film combined with TiO₂ formed a heterojunction, achieving a peak photocurrent density of 6.36 µA/cm² under visible light. This is 2.2 and 53.0 times higher than standalone SnS-In and TiO₂ films, respectively. This superior performance is attributed to the optimal In³⁺ doping effectively modulating the SnS band structure and the type-II heterojunction promoting efficient charge separation. This work demonstrates a promising strategy for optoelectronic conversion and photocatalysis by combining In-doping for SnS band structure engineering with TiO₂ heterostructure construction. Full article

Using ultrasound-assisted extraction, we obtained a chlorophyll-rich extract from Opuntia ficus-indica cladodes (OFI) characterized through thin-layer chromatography (TLC), Fourier-transform infrared spectroscopy (FTIR), and spectrophotometric absorption analysis. The dye exhibited a strong fluorescence response in the visible range (400–800 nm) with a pronounced red emission when excited with a UV source. Antioxidant ability was evaluated via DPPH assay, showing an IC₅₀ of 185 µg/mL, highlighting its potential for reactive oxygen species scavenging. The extract was incorporated into polymethyl methacrylate (PMMA), polyvinylpyrrolidone (PVP), and polyvinyl alcohol (PVA), leading to fluorescence intensity enhancements of up to 40 times compared to the dye alone depending on matrix polarity, consistent with aggregation and polarity effects. Stability tests confirmed the dye’s resistance to CO₂ exposure, pH variations, and prolonged storage, positioning it as a viable alternative to synthetic fluorophores. These findings suggest that the OFI extract provides a functionally relevant, bio-derived dye platform promoting the valorization of agricultural by-products in high-value technological applications, highlighting a circular and scalable approach to developing ecofriendly fluorescent materials, aligning with sustainability and green technology goals. Full article

Low-temperature plasma cleaning technology has been widely used to clean various optical components precisely. After the complete removal of organic contaminants from fused silica surfaces through plasma cleaning, continuous plasma irradiation can lead to nano-defects on the fused silica surface, resulting in the degradation of optical performance. Thus, the microscale processes underlying plasma-induced surface damage on fused silica were investigated through molecular dynamics simulations, aiming to analyze the mechanisms of surface damage on optical components during plasma cleaning. Oxygen plasma bombardment disrupted fused silica bonds, leading to the successive sputtering of silicon–oxygen atoms. The quantity of sputtered silicon atoms demonstrated a linear correlation with irradiation time. The emergence of pit defects and distinctive interface damage patterns elucidated the impact of neutral oxygen atoms. Critical findings underscore the onset of significant damage beyond 33 eV, underlining plasma’s role in thinning fused silica. Temperature is a crucial factor affecting surface damage during plasma cleaning. Ultimately, investigating the surface damage mechanism of fused silica during plasma cleaning establishes a groundwork for achieving non-destructive optics cleaning. Full article

The offshore reservoir development involves large injection and production rates and high injection pressures. High-permeability flow channels usually occur in offshore unconsolidated heavy-oil reservoirs during long-term water flux, substantially impacting the production performance. As one important method for identifying channeling, the numerical simulation method with a full-fidelity model is hampered by the low computational efficiency of the history matching process. The GPSNet model is extended for polymer flooding simulations, incorporating complex mechanisms including adsorption and shear-thinning effects, with solutions obtained through a fully implicit numerical scheme. Four flow channel characteristic parameters are proposed, and an evaluation factor M for flow channel identification is established with the comprehensive evaluation method. Finally, the field application of the GPSNet model is made and validated by the tracer interpretation result. The history matching speed based on the GPSNet model is 58 times faster than the full-fidelity ECLIPSE model. In addition, the application demonstrates a high degree of consistency with tracer monitoring results, confirming the accuracy and field feasibility. The new method enables rapid and accurate identification and prediction of large and dominant channels, offering effective guidance for targeted treatment of channels and sustainable development of polymer flooding. Full article

This study introduces an innovative deflection-controlled design method (DCM) for evaluating the bearing capacity of offshore mono-bucket foundations (MBFs) in clay, integrating advanced numerical simulations using FLAC3D with the modified cam clay (MCC) soil model. Departing from conventional ultimate bearing capacity approaches, the proposed method prioritizes serviceability limits by constraining foundation deflections to ensure optimal structural performance and turbine efficiency. A systematic investigation revealed that the MBF performance is predominantly governed by eccentricity ratios and soil–structure interaction, with vertical loads exhibiting a minimal impact in a serviceability limit state. Key findings include the following: (1) the rotation center (RC) stabilizes at approximately 0.8 times the skirt length (L) under loading; (2) thin, deep MBFs (aspect ratio > 1.0) exhibit up to a 30% higher bearing capacity compared to wide, shallow configurations; (3) increasing eccentricity ratios (ε = 0.31–1.54) enhance the moment capacity but reduce the allowable horizontal force by 15–20%; (4) compressive vertical loads (υ = −0.30) slightly reduce the normalized bending moments (ω) by 5–10% at low eccentricities (ε < 0.5). The numerical framework was rigorously validated against centrifuge test data, demonstrating high accuracy (error < 3%) in predicting foundation behavior. By bridging geotechnical mechanics with practical engineering requirements, this study provides a robust and efficient design framework for MBFs, offering significant improvements in reliability and cost-effectiveness for offshore wind turbine applications. The proposed DCM successfully guided the design of an MBF in southeastern China, demonstrating its efficacy for use with homogeneous clay. Full article

In the context of the evolving global energy landscape, tight gas fields have gained in-creasing significance due to their low-porosity and low-permeability reservoirs, where natural fractures play a critical role in improving permeability and enhancing storage capacity. Foreland basins, such as the Dibei area in the northern Kuqa Depression of the Tarim Basin, are typical hosts for tight gas reservoirs, but the complex fracture development induced by multiple tectonic movements restricts natural gas exploration. This study employs core observation, imaging logging analysis, and thin-section microscopy to characterize the genetic types and development features of natural fractures in the Ahe Formation. Results show that 54% of natural fractures in the Dibei area are structurally originated, predominantly high-angle and open. The highest fracture density (0.351 fractures/m), six times that of other regions, occurs in the upper horst zones. Three fracture patterns are identified, namely fault–fold, fault-related, and monocline types. Fault–fold fractures are most developed due to folding and thrusting, while monocline zones are poorly fractured. Structural fractures are best developed in horst crests with fault–fold patterns. Fracture development is jointly controlled by folds, faults, stress, and lithology, with distinct characteristics across different structural positions and lithological combinations. Clarifying the development characteristics and distribution patterns of natural fractures in the Ahe Formation of the Dibei area facilitates accurate evaluation of high-quality reservoirs, providing crucial geological basis for optimizing hydrocarbon sweet spots and refining accumulation models in the region. Full article

Background and Clinical Significance: This case report highlights the rare but potentially sight-threatening presentation of corneal ulcers associated with methamphetamine abuse. Identifying the signs of illicit drug use is critical, as ocular complications may be overlooked without proper social history or lab confirmation. Case Presentation: A 48-year-old Hispanic male presented with progressive bilateral vision loss over four weeks, describing his condition as “blind vision.” Two weeks earlier, he had visited the emergency room after a fall caused by impaired vision and was prescribed insulin, metronidazole, and fluoroquinolone drops. At ophthalmology follow-up, visual acuity was 20/400 OD and 20/800 OS. Examination revealed bilateral stromal corneal ulcers with infiltrates. Notable systemic signs—pockmarks, poor dentition, thin body habitus, and jittery behavior—raised suspicion for methamphetamine use. He was treated with bandage contact lenses, dehydrated amniotic membranes, and a steroid-antibiotic combination drop. Conclusions: This case underscores the importance of recognizing physical signs of methamphetamine abuse, even in the absence of disclosed history. Emergency room laboratory testing confirmed methamphetamine use. Awareness of drug-induced ocular effects allows for appropriate patient education, timely intervention, and referral to addiction services. Patients should be warned that continued drug use may result in irreversible vision loss. Full article

In this study, a laboratory-precision four-high micro-rolling mill was employed to investigate the influence of grain size on the deformation behavior and fracture mechanism of a micro-rolled Cu/Al composite ultra-thin sheet. Analytical testing techniques including scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM+EDS), X-ray diffraction (XRD), and unidirectional tensile experiments were utilized. The experimental results indicate that the grain size of the Cu/Al composite ultra-thin sheet increases with increasing annealing temperature and extended holding time while undergoing the first and second micro-rolling processes. Under identical annealing conditions, secondary micro-rolling leads to an increase in the grain size of Cu, while the growth rate of Al grains is reduced. Tensile tests and fracture surface observations reveal that as the annealing temperature increases, the grain size of the once-micro-rolled Cu/Al composite ultra-thin sheet also increases. When annealing at 400 °C for 40 min, the elongation reaches a maximum of 25.6%, with a tensile strength of 106.3 MPa. For the second micro-rolled samples, a maximum tensile strength of 114.8 MPa is achieved after annealing at a temperature of 360 °C for an 80 min holding time, although the elongation is significantly lower at 3.4%. This indicates that the fracture mode of the once-micro-rolled ultra-thin Cu/Al composite sheet is ductile fracture, whereas that of the second micro-rolled sample is brittle fracture. Full article

In this work, we employ the Darmois–Israel thin-shell formalism to construct both static and dynamic thin-shell configurations surrounding traversable wormholes. Initially, using the cut-and-paste technique, we perform a linearized stability analysis in the presence of a general cosmological constant. Our results show that for sufficiently large positive values of the cosmological constant—corresponding to the Schwarzschild–de Sitter geometry—the stability regions of the wormhole solutions are significantly enhanced compared to the Schwarzschild case. Subsequently, we construct static thin-shell solutions by matching an interior wormhole geometry to an exterior vacuum spacetime across a junction surface. In the spirit of minimizing the presence of exotic matter, we identify parameter domains in which the null and weak energy conditions are satisfied at the shell. We examine the surface stress-energy components in detail, determining regions where the tangential surface pressure is either positive or negative, interpreted, respectively, as the pressure or surface tension. Additionally, an expression describing the behavior of the radial pressure across the junction is derived. Finally, we determine key geometrical characteristics of the wormhole, including the throat radius and the junction interface radius, by imposing traversability conditions. Estimates for the traversal time and required velocity are also provided, further elucidating the physical viability of these configurations. Full article

Aluminium (Al) is a widespread environmental contaminant known to induce oxidative stress and genotoxic effects in aquatic organisms. While its neurotoxic properties are well documented, the molecular impact of Al on the visual system remains poorly understood. In this study, adult zebrafish (Danio rerio) were exposed to 11 mg/L Al for 10, 15, and 20 days to investigate the oxidative and genotoxic responses in ocular tissue. Activities of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) were measured in eye supernatants to detect oxidative stress. Additionally, the activities of poly (ADP-ribose) polymerase (PARP) and poly (ADP-ribose) glycohydrolase (PARG) were assessed in tissue homogenates to evaluate oxidative DNA damage and repair processes. The results indicate that these enzymes respond to counteract the increased reactive oxygen species (ROS) induced by aluminium exposure. However, their activity may not sufficiently reduce ROS levels to fully prevent oxidative DNA damage, as evidenced by a significant rise in PARP activity during short exposure times. Over longer exposures, PARP activity returned to baseline, suggesting ocular cells may adapt to aluminium toxicity. We propose that this reduction in PARP activity is a cellular survival mechanism, as sustained activation can deplete energy reserves and trigger cell death. Finally, thin-layer chromatography confirmed that PARG facilitates the breakdown of poly (ADP-ribose) (PAR) into ADP-ribose, demonstrating the dynamic regulation of the PAR cycle, which is crucial to preventing parthanatos. Full article

The increasing application of plain bearings in various industries, especially under challenging conditions like thin lubricating films and high temperatures, necessitates effective monitoring to prevent failures and ensure reliable performance. While sensor-based monitoring incurs significant costs and complex installation due to physical sensors and data acquisition systems, model-based tracking offers a more cost-effective alternative. Model-based monitoring relies on mathematical or physics-based models to estimate system behaviour, reducing the need for extensive sensor data. However, reliable results depend on real-time capable and precise simulation models. Conventional real-time modelling techniques, including analytical calculations, empirical formulas, and data-driven methods, exhibit significant limitations in real-world applications. Analytical methods often have a restricted range of applicability and do not match the accuracy of numerical methods. Meanwhile, data-driven approaches rely heavily on the quality and quantity of training data and are inherently constrained to their training domain. Recently, Physics-Informed Neural Networks (PINNs) have emerged as a promising solution for model-based monitoring to capture complex system behaviour. This approach combines physical modelling with data-driven learning, allowing for better generalisation beyond the training domain while reducing reliance on extensive data. Thus, this study presents an approach for load monitoring in radial plain bearings using PINNs. It extends the application of PINNs by relying solely on simple sensor inputs, such as radial load and rotational speed, to predict the hydrodynamic pressure and oil film thickness distribution under varying stationary conditions. The real-time model is trained, validated, and evaluated within and beyond the training domain using elastohydrodynamic simulation results. The developed real-time model enables load monitoring in plain bearings by identifying critical hydrodynamic pressure and oil film thickness values using readily available speed and load sensor data under varying stationary conditions. Full article

A small, strongly schistose Ni-laterite occurrence at the Vermion ophiolite (40°26′ Ν, 22°10′ Ε), Northen Greece, along a strong shear zone, is characterized by relatively high Ni, Co and Mn contents, magnetite as the dominant mineral, garnet (grossularite), theophrastite [β-Ni(OH)₂], otwayite-like phase (ideally Ni₂CO₃(OH)₂.H₂O), (Ni, Co, Mn)-hydroxides, and Ni-phyllosilicates. New analytical data, including black-white and color back-scattered electron images (BSEIs), elemental mapping and scanning, and Raman Spectroscopy, alongside silicates and hydroxides revealed the presence of varying silica content (less than 1 to 29 wt.%) in theophrastite and in (Ni, Co, Mn ± Fe)-hydroxides, although the X-ray powder diffraction data correspond to those of pure hydroxides. The gradual stacking of fine fibrous otwayite-like crystals to the boundaries of successive thin layers and within layers themselves, results in porous mineral phases of varying density shifting towards more compact mineral with increasing residence time. The presented data suggest that a potential explanation of the presence of Si in theophrastite may be the precipitation of Si after initial Ni-hydroxyl-carbonate fine crystals deposition. A potential sequence of the stability of Ni-minerals at Vermion may be as follows: Hydroxyl-carbonates < [β-Ni(OH)₂] (theophrastite) < (Ni, Co, Mn)(OH)₂ < Ni-phyllosilicates; this may be a significant factor for Ni-exploration in Ni-larerite deposits. Full article

In 2020, a high-intensity wildfire burned over 35,000 ha in the Santa Cruz Mountains of California, including over 1700 ha of old-growth coast redwood forest. This event created a unique opportunity to evaluate post-fire succession. We compared vegetation recovery in high versus low/moderate severity burned areas using data collected one year and four years following the fire. Random plot sampling was conducted at Big Basin Redwoods State Park to assess the regeneration of trees, shrubs, and herbaceous species. Descriptive and inferential statistical analyses were used to assess recovery over time and across burn severities. Results indicate significant increases in shrub cover and richness over time, with a positive association between shrub recruitment and high-severity fire. Notably, the fire-adapted species blue blossom (Ceanothus thyrsiflorus Eschsch.), which was not recorded one year following the fire, dominated the shrub layer after four years, particularly in higher severity areas. Herbaceous species also exhibited an increase in cover and richness over time, though a substantial portion of that increase was based on non-native species recruitment. Analysis did not indicate a significant relationship between fire severity and herbaceous species recovery, however. The regeneration of tree species occurred both through seedling recruitment and basal sprouting. The recruitment of basal sprouts was prolific following the fire, particularly for coast redwood. The number of basal sprouts declined significantly during the time frame of this study, as the sprouts became larger and began to self-thin. Seedling abundance, on the other hand, exhibited an approximately 30-fold increase. Seedling recruitment was primarily driven by coast redwood (Sequoia sempervirens [Lamb. ex D.Don] Endl) and Douglas fir (Pseudotsuga menziesii [Mirb.] Franco) and was positively correlated with low/moderate fire severity. These findings underscore the complex interactions shaping post-fire forest dynamics and highlight the importance of understanding such patterns to inform management strategies that support the resiliency of coast redwood forests in an era of increasing wildfires. Full article

Sweat-based electrochemical sensors for wearable applications have attracted substantial interest due to their non-invasive nature, compact design, and ability to provide real-time data. Remarkable advancements have been made in integrating these devices into flexible platforms. While thin-film polymer substrates are frequently employed for their durability, the prolonged buildup of sweat on such materials can disrupt consistent sensing performance and adversely affect skin comfort over extended periods. Therefore, investigating lightweight, comfortable, and breathable base materials for constructing working electrodes is essential for producing flexible and breathable sweat electrochemical sensors. In this study, nylon fabric was chosen as the base material for constructing the working electrode. The electrode is prepared using a straightforward printing process, incorporating Ti₃C₂T_X MXene/polyaniline and methylene blue as modification materials in the electronic intermediary layer. The synergistic effect of the modified layer and the multi-level structure of the current collector enhances the electrochemical kinetics on the electrode surface, improves electron transmission efficiency, and enables the nylon fabric-based electrode to accurately and selectively measure glucose concentration in sweat. It exhibits a wide linear range (0.04~3.08 mM), high sensitivity (3.11 μA·mM⁻¹), strong anti-interference capabilities, and high stability. This system can monitor glucose levels and trends in sweat, facilitating the assessment of daily sugar intake for personal health management. Full article

This article introduces a flexible time series regression model known as the Mixture of Integer-Valued Generalized Autoregressive Conditional Heteroscedasticity (MINGARCH). Mixture models provide versatile frameworks for capturing heterogeneity in count data, including features such as multiple peaks, seasonality, and intervention effects. The proposed model is applied to regional COVID-19 data from Malaysia. To account for geographical variability, five regions—Selangor, Kuala Lumpur, Penang, Johor, and Sarawak—were selected for analysis, covering a total of 86 weeks of data. Comparative analysis with existing time series regression models demonstrates that MINGARCH outperforms alternative approaches. Further investigation into forecasting reveals that MINGARCH yields superior performance in regions with high population density, and significant influencing factors have been identified. In low-density regions, confirmed cases peaked within three weeks, whereas high-density regions exhibited a monthly seasonal pattern. Forecasting metrics—including MAPE, MAE, and RMSE—are significantly lower for the MINGARCH model compared to other models. These results suggest that MINGARCH is well-suited for forecasting disease spread in urban and densely populated areas, offering valuable insights for policymaking. Full article