Search Results (1,157)

The widespread use of petroleum derivatives in industrial settings poses a challenge due to their toxicity and the difficulty of removing them from tanks, pipes, and equipment. Conventional degreasers are generally expensive, toxic, and harmful to workers’ health and the environment. In this study, an environmentally friendly biodetergent formulated from natural ingredients was produced in a pilot plant with 480 L h⁻¹ capacity, in 250 L homogenizers, at 3500 rpm and 80 °C, and its performance evaluated under different operating conditions. Furthermore, the biodetergent efficiency was compared with that of commercial degreasers commonly used in industrial settings. Stability tests indicated 100% stable emulsion with 2.0% fatty alcohol and 1.0% stabilizing gum after one week of storage. In application tests, the biodetergent promoted up to 100% removal of heavy fuel oil (OCB1) and diesel from metal surfaces, both in concentrated and (1:1 v/v) diluted forms. In direct comparisons, the product performed equally or better than commercial degreasers, notably removing >95% of OCB1 in 10 min and maintaining efficiency after multiple reuse cycles. Unlike acidic or solvent-based formulations, the biodetergent did not induce corrosion on pieces or release toxic vapors when applied to heated surfaces. In summary, the developed bioproduct demonstrated industrial scalability and high efficiency, constituting a sustainable alternative for petrochemical cleaning operations in onshore and offshore environments. Full article

To address the limited environmental perception capability and the difficulty of achieving consistent and efficient representation of the workspace feasible domain caused by high dust concentration, uneven illumination, and enclosed spaces in underground coal mines, this paper proposes a digital spatial construction and representation method for underground environments by integrating RGB-D depth vision with ORB-SLAM3. First, a ChArUco calibration board with embedded ArUco markers is adopted to perform high-precision calibration of the RGB-D camera, improving the reliability of geometric parameters under weak-texture and non-uniform lighting conditions. On this basis, a “dense–sparse cooperative” OAK-DenseMapper Pro module is further developed; the module improves point-cloud generation using a mathematical projection model, and combines enhanced stereo matching with multi-stage depth filtering to achieve high-quality dense point-cloud reconstruction from RGB-D observations. The dense point cloud is then converted into a probabilistic octree occupancy map, where voxel-wise incremental updates are performed for observed space while unknown regions are retained, enabling a memory-efficient and scalable 3D feasible-space representation. Experiments are conducted in multiple representative coal-mine tunnel scenarios; compared with the original ORB-SLAM3, the number of points in dense mapping increases by approximately 38% on average; in trajectory evaluation on the TUM dataset, the root mean square error, mean error, and median error of the absolute pose error are reduced by 7.7%, 7.1%, and 10%, respectively; after converting the dense point cloud to an octree, the map memory footprint is only about 0.5% of the original point cloud, with a single conversion time of approximately 0.75 s. The experimental results demonstrate that, while ensuring accuracy, the proposed method achieves real-time, efficient, and consistent representation of the 3D feasible domain in complex underground environments, providing a reliable digital spatial foundation for path planning, safe obstacle avoidance, and autonomous operation. Full article

To investigate the health risks of particulate matter during spring dust storms in Beijing, this study selected atmospheric particulate samples collected during a typical dust storm event in March 2021. The DNA damage rates induced by PM_2.5 and PM₁₀ were measured using the Plasmid Scission Assay (PSA) and were used as an indicator of their oxidative potential. Water-soluble heavy metal elements (WSHM) in the samples were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Results indicate that due to the influence of the dust storm, the monthly average PM_2.5 mass concentration in March 2021 reached as high as 83 μg/m³, which could potentially raise the difficulty of air pollution control. It was found that during the dust storm event, PM_2.5 induced a higher DNA damage rate (mean 42.35% at an experimental dose of 200 μg/mL in the PSA) than PM₁₀ (mean 40.46% under the same experimental dosage). The DNA damage rates of dust storm particles showed a positive correlation trend (r = 0.60) with total WSHM concentrations. Exposure toxicity, calculated by multiplying the DNA damage rates under certain experimental PM doses by the PM mass concentrations, showed that the exposure risk of PM_2.5 during dust storms even exceeded that of PM_2.5 during haze events. This study reveals the potential toxicity and health risks associated with PM during dust storms, which calls for increased attention. Full article

Seismic monitoring is a crucial step in ensuring the safety and resilience of building structures. The implementation of effective monitoring systems, particularly across large-scale, complex building clusters, is currently hindered by the limitations of traditional sensor placement methods, which suffer from low efficiency, high subjectivity, and difficulties in replication. This paper proposes an innovative AI-based Automated Layout Method for seismic monitoring devices, leveraging building geometric recognition to provide a scalable, quantifiable, and reproducible engineering solution. The core methodology achieves full automation and quantification by innovatively employing a dual-channel approach (images and vectors) to parse architectural floor plans. It first converts complex geometric features—including corner coordinates, effective angles, and concavity/convexity attributes—into quantifiable deployment scoring and density functions. The method implements a multi-objective balanced control system by introducing advanced engineering metrics such as key floor assurance, central area weighting, spatial dispersion, vertical continuity, and torsional restraint. This approach ensures the final sensor configuration is scientifically rigorous and highly representative of the structure’s critical dynamic responses. Validation on both simple and complex Reinforced Concrete (RC) frame structures consistently demonstrates that the system successfully achieves a rational sensor allocation under budget constraints. The placement strategy is physically informed, concentrating sensors at critical floors (base, top, and mid-level) and strategically utilizing external corner points to maximize the capture of torsional and shear responses. Compared with traditional methods, the proposed approach has distinct advantages in automation, quantification, and adaptability to complex geometries. It generates a reproducible installation manifest (including coordinates, sensor types, and angle classification) that directly meets engineering implementation needs. This work provides a new, efficient technical pathway for establishing a systematic and sustainable seismic risk monitoring platform. Full article

Background: Rhinovirus C (RV-C) is one of three species of rhinoviruses (RVs), which cause the common cold, preschool wheezing illnesses and exacerbations of asthma. RV-C types are more virulent, especially in children, but progress in developing treatments is limited by difficulties in generating high-titer virus preparations. The goals of this study were to optimize methods for large-scale production and purification of RV-C to facilitate structure and immune response studies. Methods: We optimized protocols for the propagation and purification of RV-C15a, a clinical isolate adapted to HeLa-E8 cells stably expressing virus receptor CDHR3. We compared virus yields in adherent and suspension cultures, evaluated the effects of calcium supplementation and infection timing, and tested multiple purification strategies, including ultracentrifugation, dialysis, and lipase treatment. Results: RV-C15a yields were significantly lower in suspension vs. adherent cultures despite comparable virus binding and entry, suggesting post-entry replication limitations in suspended cells. In adherent cultures, infecting soon after cell seeding and calcium supplementation reduced the time of virus production and modestly improved virus progeny yields. Surface CDHR3 expression declined over time, potentially restricting viral spread. Among purification methods, lipase treatment of infected cell lysates followed by ultracentrifugation produced highly pure and concentrated virus preparations suitable for structural and immunological applications, with high yields. Conclusions: We present a robust system for large-scale RV-C15a production in adherent HeLa-E8 cells and recommend a lipase-based purification method as a rapid and effective approach for producing high-quality viral preparations. These advances will support structural studies and accelerate the development of RV-C-targeted therapeutics and vaccines. Full article

To address the difficulty of controlling surrounding rock subjected to repeated repair-induced disturbances, the characteristics of the roadway surrounding rock and its deformation–failure mechanisms were examined. An experimental scheme for surrounding-rock control was formulated, and a three-dimensional numerical model was established. Four support schemes were evaluated to identify a rational support method and corresponding parameters: (a) rock bolts and cable bolts; (b) rock bolts, cable bolts, and floor cable bolts; (c) rock bolts, cable bolts, floor cable bolts, and U-shaped closed steel sets; and (d) rock bolts, cable bolts, floor cable bolts, U-shaped closed steel sets, and grouting. Comparative analyses were conducted in terms of plastic-zone evolution, stress-field distribution, surrounding-rock displacement, and the mechanical response of the support structures. The results indicate that, in roadways experiencing multiple repair disturbances and supported only by rock bolts and cable bolts, distinct stress-concentration zones develop within the supported surrounding rock, suggesting that reliance solely on bolts and cables is unfavorable for effective rock-mass control. Grouting improves the overall integrity and self-bearing capacity of the surrounding rock. Both the U-shaped closed support and the combined U-shaped closed support with grouting effectively restrain surrounding-rock deformation, and the corresponding stress distribution shows no pronounced stress-concentration zones. Based on the analyses of surrounding-rock displacement, support-structure loading, and incremental shear strain, the effectiveness of the support schemes in mitigating roof and floor displacement ranks, in descending order, as (d), (c), (b), and (a). Engineering practice further demonstrates that the combined support system consisting of 29U-type sets, grouted bolts, and bundle-type grouted cable bolts provides effective control over the deformation and failure of the roadway surrounding rock. Full article

Copper (Cu) and zinc (Zn) are critical for global high-tech industries and national economic security. With high-grade mineral depletion, recycling valuable metals from iron ore tailings has become a sustainable solution. A Peruvian mining company’s iron ore tailing reprocessing faces a severe challenge: surging lead (Pb) content due to increased excavation depth has rendered the original Cu-Zn bulk flotation flowsheet ineffective, causing excessive impurities in concentrates. This study first characterized the occurrence states of Cu, Pb, and Zn via multi-analytical techniques. A novel Cu-Pb-Zn iso-flotation process with step-by-step depression, coupled with optimized reagents, was proposed. It abandons initial CuSO₄ activation to reduce separation difficulty and uses targeted depressants for efficient impurity removal. Closed-circuit tests yielded a Cu concentrate (26.57% grade, 56.08% recovery) with Pb/Zn contents reduced to 2.97%/9.80%, and a Zn concentrate (44.95% grade, 75.56% recovery) with Cu/Pb controlled at 1.15%/8.31%. Experimental results demonstrate that this new flowsheet effectively mitigates the impact of high Pb content, restoring production efficiencies and offering a valuable precedent for industrial process modification. Full article

By addressing the challenges of management difficulties, insufficient integration of driver analysis, and single-dimensional analysis in the governance of illegal land use and illegal construction (collectively referred to as the “Two Illegalities”) under rapid urbanization, this study designs and implements a GIS-based governance system using Xiamen City as the study area. First, we propose a standardized data-processing workflow and construct a comprehensive management platform integrating multi-source data fusion, spatiotemporal visualization, intelligent analysis, and customized report generation, effectively lowering the barrier for non-professional users. Second, utilizing methods integrated into the platform, such as Moran’s I and centroid trajectory analysis, we deeply analyze the spatiotemporal evolution and driving mechanisms of “Two Illegalities” activities in Xiamen from 2018 to 2023. The results indicate that the distribution of “Two Illegalities” exhibits significant spatial clustering, with hotspots concentrated in urban–rural transition zones. The spatial morphology evolved from multi-core diffusion to the contraction of agglomeration belts. This evolution is essentially the result of the dynamic adaptation between regional economic development gradients, urbanization processes, and policy-enforcement synergy mechanisms. Through a modular, open technical architecture and a “Data-Technology-Enforcement” collaborative mechanism, the system significantly improves information management efficiency and the scientific basis of decision-making. It provides a replicable and scalable technical framework and practical paradigm for similar cities to transform “Two Illegalities” governance from passive disposal to active prevention and control. Full article

Neutral electrolyzed water (NW) is widely used in dentistry because of its strong bactericidal activity and high biosafety; however, its clinical application is limited by short retention time in the oral cavity and by the difficulty in maintaining and adjusting the available chlorine concentration (ACC) on-site. This study aimed to develop an on-demand NW-containing hydrogel (NWJ) that allows adjustment of ACC immediately before use while maintaining antimicrobial efficacy and handling properties. A methylcellulose–agar composite gel was prepared as a base gel and mixed with high-concentration NW to obtain prototype NWJs with target ACCs ranging 20–100 mg/L. Physicochemical properties (pH and ACC), time-dependent changes in ACC, bactericidal activity against Streptococcus mutans, and gel spreadability were evaluated. The base gel showed improved resistance to syneresis compared with an agar-only gel. All NWJs maintained a pH of approximately 6–7, exceeding the critical pH for enamel demineralization. Loss of ACC during gel preparation was less than 5%, and gradual ACC reduction was observed. Complete bactericidal activity was achieved at ACCs of 10 mg/L or higher, and gelation did not compromise antibacterial efficacy. These findings demonstrate that the developed NWJ provides a practical platform for clinical application of NW in dentistry. Full article

Background: Recently introduced nicotine pouches (NPs) are smokeless nicotine products. They are held between the lips and gums for 30 min to absorb nicotine into the bloodstream through the oral mucosa. Attractiveness may increase nicotine use, especially among young people and teens. The objective of this study is to investigate the health issues and psychological effects associated with nicotine pouch use among individuals in Saudi Arabia. Methods: A cross-sectional online survey using Google Forms. It was conducted between 13 February and 4 November 2025, in the Riyadh province of Saudi Arabia, restricted to users of nicotine pouches willing to answer a questionnaire on the occasion of buying them (at regional tobacco stores/supermarkets) or online via WhatsApp or the Telegram platform. Statistical analysis was conducted using SPSS Version 27, with a p < 0.05 indicating significance. Results: The current study included data of 489 participants, with a total of 395 participants using nicotine pouches. The most commonly reported symptoms were difficulty breathing and shortness of breath (both 40.5%), changes in taste or smell (36.7%), headache and stomach ulcers (33.4% each), and rapid or irregular heartbeat (28.4%). Most common psychological symptoms at any severity level (slightly to extremely) were appetite changes (78.7%), difficulty concentrating or focusing (75.4%), difficulty sleeping (74.9%), and increased anxiety or irritability (73.4%). Depression (72.2%), anger management (71.1%), and stress (70.4%) were also common. Regression analyses revealed that educational attainment was a significant predictor of both physical and psychological health outcomes. Conclusions: The findings show the most common physical symptoms were difficulty breathing and shortness of breath, followed by taste or smell changes, headaches, stomach ulcers, and rapid or irregular heartbeat. Appetite changes, concentration issues, sleep disturbances, and anxiety or irritability were common across all severity levels. Depression, anger issues, and stress were common. Full article

Designing long-span cable-stayed bridges in high seismic hazard zones presents significant challenges due to their flexible structural systems, the influence of multi-support excitation, and the need to control large displacements while limiting seismic demands on critical components. These difficulties are further amplified in regions with complex geology and for bridges required to maintain high levels of post-earthquake serviceability. This study develops a low-damage seismic design approach for long-span cable-stayed bridges and demonstrates its application in the New Panama Canal Bridge. Probabilistic seismic hazard assessment and site response analyses are performed to generate spatially varying ground motions at the pylons and side piers. The pylons adopt a reinforced concrete configuration with embedded steel stiffeners for anchorage, forming a composite zone capable of efficiently transferring concentrated stay-cable forces. The lightweight main girder consists of a lattice-type steel framework connected to a high-strength reinforced concrete deck slab, providing both rigidity and structural efficiency. A coordinated girder–pylon restraint system—comprising vertical bearings, fuse-type restrainers, and viscous dampers—ensures controlled stiffness and effective energy dissipation. Nonlinear seismic analyses show that displacements of the girder remain well controlled under the Safety Evaluation Earthquake, and the dampers and bearings exhibit stable hysteretic behaviours. Cable tensions remain within 500–850 MPa, meeting minimal-damage performance criteria. Overall, the results demonstrate that low-damage seismic performance targets are achievable and that the proposed design approach enhances structural control and seismic resilience in long-span cable-stayed bridges. Full article

Electroencephalography (EEG) provides valuable information about a subject’s mental state; however, developing reliable classification models remains challenging. One major difficulty lies in defining an effective feature representation, as the wide range of features proposed in the literature often leads to high-dimensional inputs, increasing the risk of overfitting, reducing generalization, and raising computational cost. A further critical challenge is the strong inter-subject variability inherent to EEG data, where distributional shifts frequently cause models trained on one individual to perform poorly on unseen subjects. This work proposes a novel family of correlation-based feature selection methods that explicitly models inter-feature relationships through correlation structures. The objective is to identify features that are simultaneously discriminative across mental states (relaxed and concentrated) and invariant across subjects, thereby improving cross-subject generalization. The proposed methods are evaluated against established feature selection and dimensionality reduction techniques using a leave-one-subject-out experimental protocol, in which models are trained on multiple participants and tested on unseen individuals. Experimental results demonstrate that the proposed approach consistently achieves superior or competitive performance compared to existing methods, particularly under strong inter-subject distribution shifts. In addition, the analysis reveals how preprocessing parameters—such as window length, overlap, and frequency band decomposition—affect classification performance and generalization. Unlike previous EEG feature selection approaches that primarily focus on feature relevance or redundancy, the proposed framework explicitly promotes domain invariance while preserving feature interpretability, without relying on subject-specific calibration. Full article

Melanoma is an aggressive skin cancer that continues to present major therapeutic difficulties. Although targeted drugs and immune checkpoint inhibitors have improved outcomes, resistance and treatment-related toxicity limit long-term benefit. In recent years, nanotechnology has been explored as a way to improve how drugs are delivered and to achieve greater tumor selectivity. Among available nanocarriers, liposomes have attracted particular interest. Built from lipid bilayers, they can carry both hydrophilic and hydrophobic molecules, and they are generally well tolerated. Importantly, their surface can be modified with polymers or targeting ligands to direct the carrier more selectively to melanoma cells. Experimental models show that liposomal drug formulations can increase concentrations in tumor tissue while limiting distribution to healthy organs. They have also been used successfully to combine different types of agents, chemotherapies, immunomodulators, and nucleic acids, within a single delivery system. These findings suggest genuine potential to address several of the shortcomings of conventional treatments. Although translation to the clinic is slowed by challenges such as formulation stability and large-scale production, liposomes represent an important step toward safer and more effective melanoma therapy within the broader field of oncologic nanotechnology. Full article

Maintaining color constancy in polymer extrusion processes is a key difficulty in manufacturing applications, as fluctuations in processing parameters greatly influence pigment dispersion and the quality of the finished product. Preliminary historical data mining analysis was conducted in 2009. This work concentrates on Opaque PC Grade 5, which constituted 2.43% of the pigment; it contained 10 PPH of resin2 with a Melt Flow Index (MFI) of 6.5 g/10 min and 90 PPH of resin1. It also employs a fixed resin composition with an MFI of 25 g/10 min. This research identified the significant processing parameters (PPs) contributing to the lowest color deviation. Interactions between processing parameters, for the same color formulation, were analyzed using statistical methods under various processing conditions. A principle-driven General Trends (GT) diagnostic procedure was applied, wherein each parameter was individually varied across five levels while holding others constant. Particle size distribution (PSD) and colorimetric data (CIE Lab*) were systematically measured and analyzed. To complete this, correlations for the impact of temperature (Temp) on viscosity, particle characteristics, and color quality were studied by characterizing viscosity, Digital Optical Microscopy (DOM), and particle size distribution at various speeds. The samples were characterized for viscosity at three temperatures (230, 255, 280 °C) and particle size distribution at three speeds: 700, 750, 800 rpm. This study investigates particle processing features, such as screw speed and pigment size distribution. The average pigment diameter and the fraction of small particles were influenced by the speed of 700–775 rpm. At 700 rpm, the mean particle size was 2.4 µm, with 61.3% constituting particle numbers. The mean particle size diminished to 2 µm at 775 rpm; however, the particle count proportion escalated to 66% at 800 rpm. This research ultimately quantifies the relative influence of particle size on the reaction, resulting in a color value of 1.36. The mean particle size and particle counts are positively correlated; thus, reduced pigment size at increased speed influences color response and quality. The weighted contributions of the particles, 51.4% at 700 rpm and 48.6% at 800 rpm, substantiate the hypothesis. Further studies will broaden the GT analysis to encompass multi-parameter interactions through design experiments and will test the diagnostic assessment procedure across various polymer grades and colorants to create robust models of prediction for industrial growth. The global quality of mixing polycarbonate compounding constituents ensured consistent and smooth pigment dispersion, minimizing color streaks and resulting in a significant improvement in color matching for opaque grades. Full article

With the increasing requirements for “Green Mine” construction, Cemented Tailings Backfill (CTB) has emerged as the preferred strategy for solid waste management and ground pressure control in underground metal mines. However, full tailings, characterized by wide particle size distribution and high fine-grained content, exhibit complex physicochemical properties that lead to significant non-linear behavior in slurry rheology and strength evolution, posing challenges for accurate prediction using traditional empirical formulas. Addressing the issues of significant strength fluctuations and difficulties in mix proportion optimization in a specific lead–zinc mine, this study systematically conducted physicochemical characterizations, slurry sedimentation and transport performance evaluations, and mechanical strength tests. Through multi-factor coupling experiments, the synergistic effects of cement type, cement-to-tailings (c/t) ratio, slurry concentration, and curing age on backfill performance were elucidated. Quantitative results indicate that solids mass concentration is the critical factor determining transportability. Concentrations exceeding 68% effectively mitigate segregation and stratification during the filling process while maintaining optimal fluidity. Regarding mechanical properties, the c/t ratio and concentration show a significant positive correlation with Uniaxial Compressive Strength (UCS). For instance, with a 74% concentration and 1:4 c/t ratio, the 3-day strength increased by 1.4 times compared to the 68% concentration, with this increment expanding to 2.0 times by 28 days. Furthermore, a comparative analysis of four cement types revealed that 42.5# cement offers superior techno-economic indicators in terms of reducing binder consumption and enhancing early-age strength. This research not only establishes an optimized mix proportion scheme tailored to the operational requirements of the lead–zinc mine but also provides a quantitative scientific basis and theoretical framework for the material design and safe production of CTB systems incorporating high fine-grained full tailings. Full article