Search Results (4,352)

Water-induced deterioration of silty soil subgrade in the lower Yellow River floodplain poses a critical, long-standing engineering challenge. Most existing studies on silty soil modification prioritize strength enhancement via traditional cementitious binders (i.e., cement, lime), yet these strategies fail to fundamentally block water migration in the soil matrix. A distinct scientific gap persists: the capillary water inhibition mechanism of nano-superhydrophobic modified Yellow River alluvial silt, along with the correlation between its microstructural evolution and macroscopic engineering performance, has yet to be systematically elucidated. To fill this gap, we conducted hydrophobic modification of the targeted silt using a nano-superhydrophobic material (NSHM), and performed a systematic suite of laboratory tests to characterize its hydrophobicity, mechanical properties, water stability, and microstructural characteristics. Quantitative experimental results demonstrate that NSHM imparts remarkable water resistance to the silt: at an NSHM dosage ≥0.5%, the modified soil exhibits stable superhydrophobicity across all tested compaction degrees, with over a 99% reduction in saturated hydraulic conductivity. Notably, the hydrophobic modification only incurs a <12% reduction in the dry unconfined compressive strength (UCS) of the silt. Microscopic characterization results reveal that NSHM modifies the silt via two core pathways: uniform particle encapsulation and pore infilling, without altering the inherent mineral functional groups of the soil. This microstructural regulation reduces the average pore diameter by 38.2% and total porosity by 15.6%, while optimizing the uniformity of pore size distribution. Based on comprehensive evaluation of overall performance, a minimum NSHM dosage of 0.5% is recommended for in situ application in local silty soil subgrade. This study provides critical theoretical guidance and technical support for water damage mitigation in alluvial silty soil subgrade. Full article

Cyclocarya paliurus polysaccharides (CPP) possess various physiological functions such as lipid-lowering and antioxidant activities. However, as a complex plant-based dispersion system, the interfacial characteristics of fermented C. paliurus beverages often restrict the release of bioefficacy of the active ingredients. This study investigated the impact of particle size on the colloidal stability and lipid-lowering activity of C. paliurus beverages fermented by Lactobacillus plantarum and established an empirical correlation between the two. While the 200–300 mesh fraction showed superior physical stability, the 40–60 mesh fraction was identified as the optimal formulation in this study when balancing ROS indicators. In vivo assays using Caenorhabditis elegans demonstrated that the 40–60 mesh formulation significantly reduced MDA levels and inhibited lipid accumulation, decreasing TG content by 19–46%. Notably, the average diameter of lipid droplets decreased by 38.4%, promoting the conversion of large storage-type droplets to small/medium-sized droplets with high metabolic activity. This study reveals the trade-off between physical dispersibility and bioavailability, providing a theoretical basis for optimizing the interfacial structure of functional plant-based beverages. Full article

The formation and size evolution of gas-phase nanoparticles (NPs) in laser ablation inductively coupled plasma mass spectrometry critically influence aerosol transport, plasma ionization efficiency, and ultimately analytical accuracy. Nevertheless, burst-mode laser ablation, as an efficient and versatile strategy for controlling gas-phase NP size, remains insufficiently explored. Here, we combine experimental investigations and theoretical analysis to elucidate the mechanisms of gas-phase nanoparticle formation and size control by tuning the interpulse interval in burst-mode femtosecond (fs) laser ablation. The mean nanoparticle size exhibits a non-monotonic dependence on interpulse spacing, decreasing with a narrowing size distribution as the interval increases from 0 to 300 ps, and then increasing with distribution broadening at longer delays up to 1000 ps, closely correlating with ablation-crater depth. A characteristic transition at ~300 ps is identified, where both nanoparticle size and crater depth reach a minimum, revealing a critical timescale in pulse–plume–surface interactions. Simulations show that the interpulse interval governs the redistribution of laser energy between the surface and plume, driving a transition from surface-dominated ablation to plume-dominated absorption and partial recovery of surface coupling. This delay-dependent framework provides a unified explanation for nanoparticle formation, where particle size is determined by the competition between plume-mediated fragmentation and surface-driven material supply, and offers a basis for tailoring NP size distributions via temporal pulse shaping. Full article

Wear remains a dominant cause of performance loss and premature failure in mechanical components, motivating the development of environmentally benign surface-engineering solutions. Among thermal spray systems, high-velocity oxy-fuel (HVOF)-sprayed WC-Co coatings are widely applied under severe wear conditions. The development of nanophase coatings offers the potential for enhanced mechanical performance. However, retaining the nanostructure and limiting decarburization during deposition remain key challenges. In this study, nanophase WC-12Co feedstocks with two particle size ranges, together with Al-modified nanophase powders, were used to deposit coatings under optimized HVOF spraying conditions (spray distance 200 mm, reduced O₂/fuel ratio, and high particle velocity) and were benchmarked against a conventional WC-12Co (12 wt.% Co) coating. The coatings were characterized in terms of microstructure and phase constitution (OM, SEM/EDS, XRD) as well as thickness, porosity (0.5–3.6%), adhesion strength (up to 65 MPa), and microhardness (~1040–1210 HV). Tribological behavior was assessed by ASTM G99 pin-on-disk testing and counterbody wear was quantified via geometric volume loss estimations. The use of larger nanophase particles enabled effective nanostructure retention with limited decarburization, whereas reducing particle size intensified decarburization, promoting increased W₂C formation, and markedly reduced coating cohesion, despite lower porosity and higher hardness. Aluminum additions enhanced coating microhardness and suppressed Co₃W₃C formation, indicating improved phase stability with minimal additional decarburization. Although coating wear remained negligible for all systems, Al-containing coatings exhibited increased friction (up to 35%) and significantly higher counterbody wear (up to sevenfold) compared to the Al-free nanophase coating, which was found to correlate with coating microhardness. Overall, the results demonstrate that optimizing nanophase WC-Co coatings requires balancing competing mechanisms between microstructural stability, cohesive integrity, and tribological response, highlighting the critical role of feedstock design in tailoring coating performance. Full article

Variations in the particle size of cereal flour could influence its techno-functional properties and affect the quality of the end products. In this study, common buckwheat (Fagopyrum esculentum) seeds were milled and then sieved into five fractions (≥200, 150–200, 100–150, 80–100, and 60–80 mesh). Proximate analysis showed that the protein and ash contents of buckwheat flour decreased with decreased particle size, whereas the starch content increased. Reducing the particle size did not change the A-type crystalline structure and the short-range ordered structure of buckwheat starch, whereas the buckwheat batter flowability, foaming properties and foam stability of the batter supernatant increased. The steamed buckwheat cakes made from ≥100-mesh flour showed a desirable appearance, cross-sectional structure, color, flavor, and texture. Pearson correlation analysis revealed that the starch content and relative crystallinity of buckwheat flour were significantly positively correlated with its pasting parameters and the textural properties (springiness, cohesiveness, resilience) and overall acceptability of steamed buckwheat cake, whereas the protein, lipid, and β-sheet content of buckwheat flour showed the opposite trend. This study demonstrated that differential sieving caused a difference in particle size and chemical composition, which were key variables governing the processing performance of buckwheat flour and important to the quality of its end products. Full article

In deep geothermal engineering, concrete slabs are prone to thermal cracking. The aggregates and pores are the core influencing factors for this failure behavior. However, existing research methods are unable to accurately capture the microscopic evolution process of thermal cracking and cannot clarify the intrinsic mechanism of how the characteristics of aggregates and pores affect the initiation and propagation of cracks. This limitation restricts the in-depth understanding of the laws of concrete thermal cracking. To address this deficiency, this study employs the discrete element method (DEM) and combines the particle flow program PFC2D to construct a microscopic model of concrete disks. By setting reasonable temperature parameters and thermal load boundaries, a numerical simulation system matching the actual deep geothermal high-temperature environment is established. Three sets of quantitative variables were designed: aggregate particle size (0.003, 0.004, 0.005, 0.006), aggregate volume fraction (0.35, 0.40, 0.45, 0.50), and porosity (0.11, 0.12, 0.13, 0.14). Through controlled variable simulations, the influence laws of each variable on the formation, propagation path, and time evolution of concrete thermal cracks were explored. The quantitative research results show that an increase in aggregate particle size significantly accelerates the generation and propagation of cracks. When the particle size is 0.006, the number of cracks is the highest and the propagation rate is the fastest. The aggregate volume fraction is negatively correlated with the final number of cracks, and 0.50 is the optimal fraction, at which the number of cracks is the smallest. A decrease in the fraction will lead to intensified stress concentration in the cement paste and a sudden increase in the number of cracks. An increase in porosity significantly disrupts the material continuity. When the porosity is 0.14, the bifurcation and connection of cracks are the most significant, while a low porosity of 0.11 can effectively inhibit the overall development process of thermal cracks. In addition, compared with traditional experimental methods and continuous medium numerical simulation techniques, the discrete element method has unique advantages in revealing the internal mechanism of concrete thermal cracking at the microscopic level. It can achieve real-time tracking of the evolution of discrete micro-cracks and the internal stress distribution characteristics. This study enriches the microscopic theoretical system of concrete thermal cracking and provides reliable quantitative references and technical support for the design of thermal crack resistance of concrete in deep geothermal engineering and the optimization of material composition. Full article

Owing to the intricate mechanical coupling characteristics and the considerable difficulty in extracting synergistic spatio-temporal features from high-dimensional sensor data under fluctuating alternating loads, this study proposes a robust anomaly detection framework that combines Normalized Mutual Information (NMI) and Spatio-Temporal Graph Neural Networks (STGNN). First, NMI is utilized to quantify the nonlinear physical coupling intensity among multi-source sensors, thereby filtering out weakly correlated noise and reconstructing the spatial topological structure of the coupler system. Subsequently, a deep learning architecture incorporating Graph Convolutional Networks (GCN), Gated Recurrent Units (GRU), and one-dimensional convolutional residual connections is developed to capture the dynamic evolutionary characteristics of equipment states across both spatial interactions and temporal sequences. Finally, based on the model’s health-state predictions, a moving average algorithm is introduced to smooth the residual sequences, and an anomaly early-warning baseline is established in conjunction with the 3σ criterion. Experimental validation conducted using field service data from heavy-haul trains demonstrates that, compared to conventional serial CNN and Long Short-Term Memory (LSTM) models, the proposed method exhibits superior fitting performance and robustness against noise, effectively reducing the false alarm rate within normal working intervals. In a real-world case study, the method successfully identified variations in spatial linkage features induced by local damage and triggered timely alerts. Notably, the spatial alarm nodes were highly consistent with the fatigue crack initiation sites identified through on-site magnetic particle inspection. This study provides a viable data-driven analytical framework for the condition monitoring and anomaly identification of critical load-bearing components in heavy-haul trains. Full article

Lignite particles generate considerable dust during drying due to structural damage, which increases the dust removal costs of the drying system, pollutes the environment, and raises the risk of combustion and explosion, thereby posing a threat to the safety of the drying system. Moisture plays a crucial role in the structural damage of lignite particles during drying. In this study, lignite samples with moisture contents of 60%, 36%, and 18% were prepared and dried in hot air at 200 °C. The transfer behavior of moisture in the pore structure was investigated, and the evolution of the pore structure was observed. The relationship between pore structure evolution and moisture transfer behavior was correlated, and the mechanism of structural damage under the action of moisture during the drying process was proposed. The results demonstrated that the moisture in large pores was transported rapidly in the form of a gas–liquid mixture; the liquid moisture in the pores boiled into water vapor, and the water vapor pressure was the main reason for the destruction of the pore structure. For raw lignite, the total pore volume decreased sharply from 0.92 to 0.37 mL/g within the first 360 s of drying, and the fractal dimension dropped from 2.701 to 2.545, indicating severe pore collapse. However, the moisture in small pores migrated by molecular diffusion, which is nondestructive to the lignite structure. Full article

Concentrations of microplastic particles (MPs) in the environment are low, and cellular uptake is difficult to measure. Cancer tissue accumulates more MPs than normal tissue. This study aims to determine whether cellular stiffness measurements by atomic force microscopy could indicate whether cells ingested MPs. In this study, spheroids with different compositions were exposed to MPs, and Young’s moduli were compared to fluorescent readings of MP uptake in monolayer cultures. The tested cancer cell lines differed in their basal Young’s modulus and in the increases observed upon MP exposure, both in monolayer and spheroid culture. Young’s moduli of the THP-1-containing spheroids were higher than those of spheroids without macrophages and were higher after MP exposure than before. In monolayer culture, softer cells showed larger increases in Young’s modulus after MP exposure than did stiffer cells. The Young’s moduli of the cell monolayers under static and dynamic conditions were positively correlated. Young’s modulus could serve as a parameter for MP uptake and can differentiate MP-containing spheroids from non-exposed spheroids. In monolayer culture, Young’s modulus can identify cell lines that ingested MPs. However, complicated use and low throughput limit the broad application of atomic force microscopy in biological evaluation. Full article

Driven by global carbon reduction targets, supersulfated cement has emerged as a promising low-carbon cementitious material. This study investigates the influence of a polycarboxylate superplasticizer (PCE) on the rheological behavior and early interfacial evolution of phosphogypsum-based supersulfated cement (PSSC). Rheological measurements, pore solution ion analysis, hydration heat analysis, X-ray diffraction (XRD), and scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM–EDS) are employed to correlate early hydration processes with structural development. The results indicate that the incorporation of PCE significantly reduces the initial yield stress and moderates the structural build-up rate. At a PCE dosage of 0.3 wt.%, the initial static yield stress decreases from 1313 Pa to approximately 125 Pa, while the structural build-up index I_s,s reaches 10.19, indicating improved particle dispersion while maintaining progressive structural reconstruction during hydration. Phosphogypsum (PG) functions not only as a sulfate source but also as an active interfacial substrate that promotes the preferential nucleation of AFt on its surface. In the absence of PCE, continuous Ca–P-enriched layers form on PG particles, accompanied by localized AFt accumulation. After the incorporation of PCE, the primary crystalline phases remain unchanged; however, gypsum dissolution and AFt formation are delayed. Meanwhile, Ca–P enrichment shifts from continuous coverage to a more dispersed distribution, promoting the spatially separated growth of AFt crystals rather than dense localized aggregation. Overall, PCE influences the evolution of the structure and properties of the system by regulating early interfacial reactions and the spatial organization of hydration products. Full article

In the present paper, In₂O₃ NPs were synthesized by a wet-chemical method, in the absence and presence of the surfactant, and deposited as thin films on silicon substrates. After deposition, the films were subjected to rapid thermal annealing (RTA) at 550 °C, 750 °C, and 900 °C, for 300 s, under an inert atmosphere. The correlation between the morphological, structural, and optical characteristics, the wetting capacity of In₂O₃ films synthesized under different synthesis conditions, and the influence of the RTA treatment are presented. The vibrations of In-O bonds for In₂O₃ samples were confirmed using FTIR spectroscopy. Structural analysis shows that In₂O₃ NPs have a cubic crystalline structure, but with the increase in temperature at 900 °C, diffraction peaks characteristic of the tetragonal phase of indium appear, correlated with a decrease in lattice parameters, as a result of the crystallinity. The morphology of the In₂O₃ samples was studied by SEM, revealing predominantly spherical and uniformly distributed particles with nanometric sizes. The absorption spectra of the In₂O₃ NPs showed peaks in the ultraviolet region, and the high energy bandgap value of the In₂O₃ films varied between 3.28 and 4.33 eV, depending on the samples and RTA treatment. The contact angle measurements of In₂O₃ films determined the wetting capacity of the surface, reflecting changes in surface morphology and structure induced by the RTA process. The results suggest that In₂O₃ thin films with spherical nanoparticles, good wettability, and percolation can be used for the development of sensors with increased selectivity and sensitivity. Full article

Volumetric collapse, a critical phenomenon in clayey soils, is characterized by a sudden reduction in volume when subjected to wetting under a specific effective vertical stress. This behavior is primarily caused by the breakdown of cementing bonds between particles in the soil’s interstitial spaces. Our study, which examines the impact of unit weight and wetting on the collapse potential of clayey soils under various stress conditions, has practical implications for geotechnical engineers. We evaluated three-unit weights spanning from loose to compacted states and assessed collapse behavior at various stress levels. Even in the observations of the microstructure under a scanning electron microscope, which corroborated the images, the pathology is evident. The results demonstrate an explicit dependency between unit weight and collapsibility. Statistical analysis revealed that unit weight was the predominant factor influencing the outcomes, with the magnitude of applied stress being identified as a secondary yet notable determinant. Furthermore, the non-linear interactions, as elucidated through ANOVA and Tukey’s HSD tests, serve as instrumental methodologies in this analytical framework. The findings underscore a significant correlation between applied stress and collapse potential, underscoring the crucial role of soil densification in mitigating the risks associated with collapse phenomena. Full article

To achieve the resource utilization of waste tires and improve the mechanical performance of cemented tailings backfill, rubber–cemented tailings backfill (R-CTB) specimens were prepared with four rubber particle sizes (20-, 40-, 60-, and 80-mesh) and four contents (2%, 4%, 6%, and 8%). A 0% rubber control group was introduced to address the lack of quantitative comparison. Uniaxial compression, digital image correlation (DIC), and scanning electron microscopy (SEM) were used to study mechanical behavior, energy evolution, and microstructural characteristics at 7 and 28 days. Results indicate that strength and elastic modulus first increase then decrease with particle size and decrease with content rise. Compared with the control group, R-CTB shows lower strength but significantly higher ductility and energy dissipation. Finer particles cause strain localization; higher content and finer size increase pores and weaken interfaces. Rubber incorporation transforms failure from brittle to ductile, providing a basis for engineering application. Full article

Oxalis tuberosa (Oca) is traditionally cultivated in the high Andean regions of Peru and represents a promising alternative source of starch with potential industrial uses, ranking among the most essential tubers after the potato. This study aimed to evaluate the physicochemical, morphological, techno-functional, and thermal properties of starch isolated from three specific varieties of Oca (yellow, black, and white) harvested at the Ccanccayllo production center in Andahuaylas, Peru. The isolated starches exhibited high purity, characterized by high luminosity (L* > 92.28) and a whiteness index exceeding 92.10. Moisture content ranged from 9.36% to 10.01%, correlating with low water activity (a_w = 0.44), indicating stability. Notably, the amylose content was significantly higher than that of other previously studied Oca varieties. This composition contributed to a favorable water absorption capacity, solubility index, swelling power, and viscosity, with the white variety displaying superior functional performance. Colloidal stability in aqueous media was moderate, as indicated by zeta potential analysis. Particle size analysis revealed granules ranging from 26.32 to 27.74 μm, with elongated and oval morphologies confirmed by SEM, displaying characteristic functional groups. Thermal analysis (DSC) demonstrated gelatinization temperatures between 52.73 and 53.12 °C and enthalpies ranging from 4.92 to 6.11 J/g, while Thermogravimetric Analysis (TGA) indicated thermal degradation up to approximately 74–80%. These findings suggest that the studied Oca starches possess significant potential for application in the food and pharmaceutical industries due to their distinct functional properties. Full article

This study investigates the influence of rock mass discontinuities on blast-induced ground vibration attenuation in a marble quarry in eastern Taiwan. A total of 53 blasts and 106 vibration records were collected and analyzed using image-based rock mass characterization with WipFrag (Version 4) software. Discontinuity conditions were quantified through the joint factor (JF), defined by the median size (D50) and maximum size (D100) from cumulative size distribution curves. The PPV (peak particle velocity) data were fitted using the USBM, Sadovsky, and a modified Simangunsong equation incorporating a discontinuity correction factor. The modified Simangunsong model yielded the highest correlation (R² = 0.8632), followed by the Sadovsky (R² = 0.8067) and USBM (R² = 0.7674) equations, indicating improved in-sample fitting performance when discontinuity effects are included. The results show that explicitly considering discontinuity effects enhances the reliability of PPV estimates for the studied site and that highly fractured rock masses with smaller block sizes result in greater vibration attenuation. The study demonstrates that a practical approach to quantify discontinuities through image analysis and embedding them into empirical PPV attenuation models can be used to refine quarry blasting design for vibration control purposes. Full article