Search Results (207)

To address the limitations of existing fault diagnosis methods for excitation dry-type transformers, such as inadequate utilization of multi-axis vibration data, low recognition accuracy under complex operational conditions, and limited computational efficiency, this paper presents a lightweight fault diagnosis approach based on the fusion of multi-channel vibration signals and visual features. Initially, a multi-physics field coupling simulation model of the excitation dry-type transformer is developed. Vibration data collected from field-installed three-axis sensors are combined to generate typical fault samples, including normal operation, winding looseness, core looseness, and winding eccentricity. Due to the high dimensionality of vibration signals, the Symmetrized Dot Pattern (ISDP) method is extended to aggregate and map time- and frequency-domain information from the x-, y-, and z-axes into a two-dimensional feature map. To optimize the inter-class separability and intra-class consistency of the map, Particle Swarm Optimization (PSO) is employed to adaptively adjust the angle gain factor (η) and time delay coefficient (t). Keypoint descriptors are then extracted from the map using the Oriented FAST and Rotated BRIEF (ORB) feature extraction operator, which improves computational efficiency while maintaining sensitivity to local details. Finally, an efficient fault classification model is constructed using an Adaptive Boosting Support Vector Machine (Adaboost-SVM) to achieve robust fault mode recognition across multiple operating conditions. Experimental results demonstrate that the proposed method achieves a fault diagnosis accuracy of 94.00%, outperforming signal-to-image techniques such as Gramian Angular Field (GAF), Recurrence Plot (RP), and Markov Transition Field (MTF), as well as deep learning models based on Convolutional Neural Networks (CNN) in both training and testing time. Additionally, the method exhibits superior stability and robustness in repeated trials. This approach is well-suited for online monitoring and rapid diagnosis in resource-constrained environments, offering significant engineering value in enhancing the operational safety and reliability of excitation dry-type transformers. Full article

This study evaluates the mechanical performance and predictive modeling of fine-grained soils stabilized with crushed aggregate residue (CAR) or crushed limestone waste (CLW) and Portland cement by integrating the porosity–binder index ($\eta /C_{\mathrm{i}\mathrm{v}}$) and Machine Learning (ML) techniques. Laboratory testing included unconfined compressive strength (q_u) and small-strain shear modulus (G_o) measurements on mixtures containing 15% and 30% CAR and 3% and 6% cement, compacted at dry unit weights between 1.69 and 1.81 g·cm⁻³ and cured for 7 and 28 days. Results revealed that strength and stiffness increased significantly with both cement and CAR contents. The mixture with 30% CAR and 6% cement exhibited the highest mechanical performance at 28 days (q_u = 1550 kPa and G_o = 6790 MPa). When mixtures are compared within the same curing period, the role of CAR and cement becomes evident. At 28 days, increasing CAR from 15% to 30% led to a moderate rise in q_u (from 1390 to 1550 kPa) and G_o (from 6220 to 6790 MPa). Likewise, at 7 days, increasing cement from 3% to 6% at 15% CAR produced significant gains in q_u (207 to 693 kPa) and G_o (2090 to 4120 MPa). The porosity–binder index showed strong correlations with q_u (R² = 0.94) and G_o (R² = 0.92). The ML models further improved accuracy, achieving R² values of 0.99 for q_u and 0.97 for G_o. Although the index already performed well, the additional gain provided by ML is meaningful because it reduces prediction errors and better captures nonlinear interactions among mixture variables. This results in more reliable estimates for mix design, confirming that the combined use of $\eta /C_{\mathrm{i}\mathrm{v}}$ and ML offers a robust framework for predicting the behavior of soil–cement–CAR mixtures. Full article

Filling-type large-size cement-stabilized macadam (F-LSBC) is a promising base material for mitigating reflection cracking in semi-rigid pavements. However, its engineering application is hindered by the challenge of balancing strength, crack resistance, and construction adaptability. More fundamentally, the relationship between micromechanical features—especially the interfacial transition zone (ITZ)—and the macroscopic behavior of filling-type cement-stabilized composites remains insufficiently understood. This study used conventional cement-stabilized macadam (CSM) as a reference and combined nanoindentation with macro-scale mechanical, fatigue, and drying shrinkage tests to clarify the micro–macro mechanisms of F-LSBC. Results show that the ITZ in F-LSBC exhibits substantially lower elastic modulus (reduced by 60–75%) and hardness (reduced by 55%), along with greater porosity and phase volume fraction than CSM. Cluster analysis revealed a thicker ITZ (55–90 μm vs. 40 μm), indicating notable interfacial weakening. These microstructural features lead to reduced strength and fatigue life. Nevertheless, due to its high coarse aggregate content and weak-interface-induced “crack-without-displacement” mechanism, F-LSBC demonstrates enhanced shrinkage resistance, with drying shrinkage reduced to 81.36% of that of CSM at 180 days. The findings emphasize the key role of ITZ characteristics in determining performance and suggest that improved interface engineering could enhance durability and shrinkage control in pavement bases. Full article

The limited heat stability of skim milk powder (SMP) constrains its application in high-temperature processes. While dry heating can improve its thermal resistance, it often accelerates the advanced Maillard reaction, compromising protein quality. This study applied low relative humidity conditions (<10% RH) during dry heating to modulate the Maillard reaction, aiming to enhance the heat resistance of SMP and derive recombined filled evaporated milk emulsions with fewer undesirable changes in colour and solubility. SMP was subjected to dry heating at 80, 100, and 120 °C for durations ranging from 2 to 20 min (at 120 °C) and up to 16 h (at 80 °C). The progression of the Maillard reaction and associated protein modifications were evaluated. The results indicate that the advanced Maillard reaction was retarded, evidenced by minimal colour development and well-preserved protein solubility (90–97%, n = 3), determined using the Lowry assay on the supernatants. The hydroxymethylfurfural and protein carbonyl contents increased only moderately with temperature and time. Moreover, the sulfhydryl group content remained largely stable, consistent with limited disulfide-mediated aggregation. Heat treatment of SMP at 120 °C for 10 min greatly improved its heat stability, as reflected by a 25-fold reduction in the volume-weighted average diameter (D_4,3; 95% CI = 3 to 47) and a 108-fold reduction in the consistency coefficient (K; 95% CI = 12 to 200) of the SMP-derived sterilised recombined filled evaporated milk (RFEM) compared to the control. These findings demonstrate that dry heating under low RH helps to improve the functional properties of SMP without inducing the detrimental effects associated with advanced Maillard products. Full article

Pea protein isolates (PPIs) from Pisum sativum have emerged as strategic ingredients at the interface of nutrition, sustainability, and functional food design. This review synthesizes advances linking isolation procedures with molecular structure and techno-functional performance. We compare alkaline extraction–isoelectric precipitation with wet and dry fractionation, as well as green/fermentation-assisted methods, highlighting the purity–functionality trade-offs driven by denaturation, aggregation, and the removal of anti-nutritional factors. We relate globulin composition (vicilin/legumin ratio), secondary/tertiary structure, and disulfide chemistry to interfacial activity, solubility, gelation thresholds, and long-term emulsion stability. Structure-guided engineering strategies are critically evaluated, including enzymatic hydrolysis, deamidation, transglutaminase cross-linking, ultrasound, high-pressure homogenization, pH shifting, cold plasma, and selected chemical/glycation approaches. Application case studies cover high-moisture texturization for meat analogues, emulsion and Pickering systems, fermented dairy alternatives, edible films, and bioactive peptide-oriented nutraceuticals. We identify bottlenecks—weak native gel networks, off-flavors, acidic pH performance, and batch variability—and outline process controls and synergistic modifications that close functionality gaps relative to animal proteins. Finally, we discuss sustainability and biorefinery opportunities that valorize soluble peptide streams alongside globulin-rich isolates. By integrating extraction, structure, and function, the review provides a roadmap for designing PPI with predictable, application-specific performance. Full article

Soil aggregates are critical determinants of soil erosion resistance and nutrient retention capacity, while freeze–thaw cycles (FTCs) induce the structural reorganization of soil aggregates, thereby altering soil stability and influencing soil organic carbon (SOC) sequestration. This study was located in the Minjia River Basin in the typical seasonal freeze–thaw areas of the Loess Plateau and aimed to quantify the effects of FTCs on soil aggregate stability and SOC content under different land use types. Farmland, grassland, and forestland with more than 20 years of usage in the region were selected, and a 0–20 cm soil layer was subjected to seven FTCs (−8 °C to 20 °C), followed by wet and dry sieving classification, focusing on soil aggregate distribution, aggregate stability, mean weight diameter (MWD), geometric mean diameter (GMD), aggregate particle fractal dimension (APD), and SOC content of the aggregate. The results showed that soil aggregates in all land use types were dominated by macroaggregates (>2 mm), with the proportion in forestland (61–63%) > grassland (54–58%) > farmland (38–51%). FTCs enhanced aggregate stability across all land use types, especially in farmland. Concurrently, FTCs reduced the SOC content in all aggregate size fractions, with reduction rates ranging from farmland (9.00–21%) to grassland (4–26%) to forestland (5–31%). Notably, FTCs significantly increased the contribution of 2–5 mm water-stable (WS) aggregates to SOC sequestration, with increment rates of 86% (farmland), 80% (grassland), and 86% (forestland). Furthermore, FTCs altered the correlation between SOC content and aggregate stability. Specifically, the positive correlations of SOC with MWD and GMD were strengthened in aggregates < 0.5 mm but weakened in aggregates >0.5 mm. These findings advance our understanding of the coupled mechanisms underlying soil erosion and carbon cycling across land uses under freeze–thaw, providing a theoretical basis for ecosystem restoration and optimized soil carbon management in cold regions. Full article

Late-Archean seawater functioned as a vast, redox-tuned colloidal system for which its kinetics were largely governed by the surface chemistry of silica–iron nanoparticles. By reproducing Archean seawater (≈0.7 M ionic strength, 25 °C) in laboratory anoxic-to-mildly oxic reactors, the ζ potential (zeta-potential(ζ)) of silica–iron nanoparticles was investigated, and we tracked how transient O₂ pulses (≤9 mg L⁻¹) regulated it. The zeta (ζ) potential was applied as the key diagnostic parameter to quantify both the sign of the ζ potential and the colloidal stability of simulated silica–iron particles in dispersion. Under strictly anoxic conditions, silica colloids (SiO₂(aq)) exhibit a persistently negative ζ potential (ζ ≈ −25 mV) in the simulated seawater (pH 6.5), arising from deprotonated silanol groups (≡Si–O⁻). Upon the addition of Fe²⁺, the inner-sphere complexation of ferrous ions on SiO₂ colloids partially replaces ≡Si–O⁻ with ≡Si–O–Fe⁺/≡Si–O–Fe–OH sites; the net negative charge density at the outer Stern plane nevertheless increases, and the ζ potential shifts from −25 mV to −30 mV. As the simulated seawater was oxygenated, the dissolved and surface-bound Fe²⁺ ions were oxidized to Fe³⁺, causing the ζ potential to exceed −30 mV. This study demonstrates that Fe²⁺–silica interactions generate electrostatic destabilization, suspending micron-scale aggregates and thus modulating the solubility and speciation of SiO₂ in early oceans. Also, transient micro-oxic pulses are shown to shift silica–iron colloids between metastable aggregation and dispersion by modulating their ζ potential. Subsequently, AFM and TEM were used to characterize the morphological changes in the colloidal particles from the liquid state to the dry state. Furthermore, infrared and XPS analyses were conducted on the colloidal samples. These findings provide certain reference significance for reconstructing the chemical evolution process of seawater in the Late-Archean period and for understanding the factors influencing the silicon–iron cycle of seawater in the Late-Archean era. Full article

Background: Pulmonary administration offers a promising route for certain biologics, particularly when treating respiratory diseases. Spray drying is widely employed to produce inhalable powders with the biologics incorporated in a stabilizing amorphous sugar. Hydrophobic amino acids such as leucine are frequently added to improve dispersibility. Objectives: While the aerodynamic benefits of leucine are well established, its influence on irreversible moisture-induced dry powder particle aggregation and protein stability during storage remains less evaluated. Methods: In this work, inulin-based powders with and without 4 wt-% leucine were spray dried and stored at 43%, 58%, 69%, and 75% relative humidity (RH) at 20 ± 2 °C. Results: Immediately after drying, both formulations displayed comparable physicochemical characteristics. However, during storage of inulin-only formulations, dry powder particles showed viscous flow and formed big irreversible aggregates after storage at an RH of 58% and above, whereas leucine-containing powders remained intact across all tested conditions up to 20 days. Protein stability was assessed using lactate dehydrogenase (LDH) and β-galactosidase (β-gal) as model proteins. At 43% RH, the Tg remained above the storage temperature, and both LDH and β-gal retained their enzymatic activity for up to 20 days. At 75% RH, however, the Tg dropped to below storage temperature, resulting in a loss of stability for LDH, consistent with its reliance on vitrification. In contrast, β-gal maintained its activity at 75% RH, indicative of stabilization through water replacement. Conclusions: Overall, these results demonstrate that leucine enhances the physical stability of inulin powders by preventing irreversible aggregation under humid conditions. However, this effect does not extend to protecting proteins reliant on vitrification. These findings highlight the potential of inulin and leucine to reduce the need for stringent storage conditions of biologics. Full article

To address the global plastic crisis, recycled plastics from food packaging were used as road materials by the dry method for practical application research. First, the main components of the recycled plastics were identified based on FTIR, and their thermal stability was evaluated through DSC, TG, and microscopic analysis. Then, the workability of the plastic–asphalt mixture was evaluated using the gyratory compaction indicator, void content, and compaction energy index (CEI). Finally, the effect of reused plastics on the cracking resistance of bituminous mixtures was examined with the Superpave IDT test. The results indicate that recycled plastics from food packaging are polyolefin composite materials, primarily consisting of Low-Density Polyethylene (LDPE), Linear Low-Density Polyethylene (LLDPE), High-Density Polyethylene (HDPE), and Polypropylene (PP), and that their thermal stability meets production requirements. Good compaction performance was observed with plastic content below 2% of the aggregate weight, while higher contents reduced void content due to the space occupied by plastics. When the plastic content increased from 0.5% to 2.0%, creep compliance decreased from 68.4% to 77.87%, while the m-value, tensile strength, and elastic energy maximum decreased by 30.77%, 5.6%, and 7%, respectively. In contrast, the failure strain, fracture energy, and maximum DSCE increased by 25.86%, 87.43%, and 133.05%, respectively. The recycled plastic enhanced the toughness of the asphalt mixture, increasing the dissipated energy during crack propagation and improving its resistance to permanent deformation. Moreover, the plastics hindered crack propagation through a bridging effect, leading to fewer cracks within plastic zones compared with surrounding areas. This study provides actionable guidance for the application of composite plastics in asphalt pavements and supports their sustainable development. Full article

Microalgae cultivation offers a sustainable approach for nutrient recovery from municipal effluents and the production of valuable biomass, although efficient harvesting remains challenging. This study evaluated the adaptation of the microalgal consortium MC-10 in a sequential batch system through reinoculation of its flocculating fraction to enhance harvesting efficiency and mineral recovery. The consortium was initially cultivated under high ionic stress to promote cell aggregation. Laboratory preadaptation using secondary municipal effluents was then conducted, followed by an outdoor evaluation. In the initial propagation stage, flocculation efficiency reached 98%. Using municipal effluents, flocculation values of 99% were obtained, with a 149% increase in flocculating biomass under laboratory conditions, and 84% flocculation with a 125% increase in biomass production under outdoor conditions, demonstrating the consortium’s stability under environmental fluctuations and its suitability for biomass harvesting. The resulting biomass showed high potential as a biofertilizer due to its mineral content (47% dry weight, DW) and acid solubility (83%), indicating high nutrient bioavailability. Additionally, it contained a total carotenoid concentration of 451 μg/g DW, adding antioxidant value. These findings support the use of microalgae cultivation for the valorization of municipal effluents through the production of easily harvestable biomass with potential for reintegration into agricultural systems. Full article

Building on the early investigation by Sidney W. Fox that dry-heated amino acids can spontaneously form microspheres, this research studies the self-organization of glycine and alanine with hydrogen in a liquid system. This study aimed to investigate the spontaneous formation of membraneless, microscale amino acid assemblies under simulated prebiotic hydrothermal conditions, such as hot mineral sources and ponds. Aqueous solutions of glycine and alanine were prepared in a hydrogen-rich mineral buffer and thermally incubated at 75 °C. Phase-contrast microscopy, transmission electron microscopy (TEM), and molecular modeling were employed to analyze the morphology and internal organization of the resulting structures. Microscopy revealed that zwitterionic glycine and alanine spontaneously self-organize into spherical microspheres (~12 µm), in which the charged –NH₃⁺ and –COO⁻ groups orient outward, while the hydrophobic methyl groups of alanine point inward, forming a stabilized internal core. The primary studies were performed with hot mineral water from Rupite, Bulgaria, at 73.4 °C. The resulting osmotic pressure difference Δπ ≈ 2490 Pa, derived from the van’t Hoff equalization. This suggests a chemically asymmetric system capable of sustaining directional water flux and passive molecular enrichment. The zwitterionic nature of glycine and alanine, which possesses both –NH₃⁺ and –COO⁻ groups, supports the formation of microspheres in our experiments. Under conditions with hot mineral water and hydrogen acting as a reducing agent in the primordial atmosphere, these amino acids self-organized into dense interfacial microspheres. These findings support the idea that thermally driven, zwitterion-mediated aggregation of simple amino acids, such as glycine and alanine, with added hydrogen, could generate membraneless, selectively organized microenvironments on the early Earth. Such microspheres may represent a plausible intermediate between dispersed organisms and microspheres. Full article

This study evaluates the physical, mechanical, durability, and environmental properties of geopolymer mortars (GMs) produced using waste tire steel fibers (WTSFs), hemp fibers (HFs), waste marble powder (WMP), and recycled fine aggregates (RFAs). Within the scope of this study, fibers were incorporated as single and hybrid types at 0.5% and 1% by volume. The addition of HFs generally reduced dry unit weight, as well as compressive and flexural strength but increased fracture energy by nearly three times. The addition of WTSFs improved compressive and flexural strengths by up to 42% and enhanced fracture energy by 840%. Hybrid fibers increased the strength values by 21% and the fracture energy by up to four times, demonstrating a clear synergistic effect between HFs and WTSFs in enhancing crack resistance and structural stability. In the durability tests conducted within the scope of this study, HFs burnt at 600 °C, while WTSFs showed signs of corrosion under freeze–thaw and acid conditions; however, hybrid fibers combined the benefits of both materials, resulting in an effective preservation of internal structure. The fact that the materials used in the production of GM samples were waste or recycled products reduced the total cost to 188 USD/m³, and thanks to these materials and the carbon-negative properties of HFs, CO₂ emissions were reduced to 338 kg CO₂/m³. The presented study demonstrates the potential of using recycled and waste materials to create sustainable building materials in the construction industry. Full article

The compaction quality of soil–rock mixture (SRM) subgrades critically influences infrastructure stability, but conventional settlement difference methods exhibit high spatial sampling bias (error > 15% in heterogeneous zones) and fail to characterize the overall compaction quality. These limitations lead to under-compaction (porosity > 25%) or over-compaction (aggregate fragmentation rate > 40%), highlighting the need for real-time monitoring. This study develops an intelligent compaction system integrating (1) vibration acceleration sensors (PCB 356A16, ±50 g range) for compaction meter value (CMV) acquisition; (2) near-infrared (NIR) moisture meters (NDC CM710E, 1300–2500 nm wavelength) for real-time moisture monitoring (sampling rate 10 Hz); and (3) an embedded edge-computing module (NVIDIA Jetson Nano) for Python-based data fusion (FFT harmonic analysis + moisture correction) with 50 ms processing latency. Field validation on Linlin Expressway shows that the system meets JTG 3430-2020 standards, with the compaction qualification rate reaching 98% (vs. 82% for conventional methods) and 97.6% anomaly detection accuracy. This is the first system integrating NIR moisture correction (R² = 0.96 vs. oven-drying) with CMV harmonic analysis, reducing measurement error by 40% compared to conventional ICT (Bomag ECO Plus). It provides a digital solution for SRM subgrade quality control, enhancing construction efficiency and durability. Full article

Ecological concrete designed by empirical method does not consider the mesoscopic influence of aggregates, resulting in problems such as low strength, excessive porosity, and poor stability with different gradations, which severely restricts the development and application of ecological concrete. To achieve the refined design of ecological concrete, a mesoscopic specific surface area design method based on statistical analysis is proposed. First, the meso-aggregate model with sub-millimeter precision was established using a high-precision 3D scanner, and CloudCompare was used to calculate the specific surface area of the mesoscopic aggregate model, laying the foundation for the statistical analysis of specific surface area. Second, statistical analysis methods verified that the mean specific surface area of 20 aggregates from a single random sampling reliably estimates the mean of the overall aggregate population. Third, the optimal water–cement ratio was calculated considering the water absorption characteristics and the mortar-wrapping capacity of aggregates; standard cubic specimens were prepared using this optimal water–cement ratio, with aggregates evenly coated with mortar and no obvious mortar settlement. Fourth, the cubic compressive strength of specimens naturally cured for 7 days was tested; experimental results showed that the cubic compressive strength of specimens formed by this project’s design method increased by more than 30% compared to the empirical design method. The results indicate that using the average volume-specific surface area of 20 aggregates to assess the overall average volume-specific surface area of aggregates is both reliable and relatively efficient. Based on the reliable estimation of the overall average volume-specific surface area of aggregates derived from this method, measurements were taken of the thickness of water films adsorbed on dry aggregates and the thickness of mortar coatings on surface-dry aggregates. Further, the optimal water–cement ratio for eco-concrete was deduced, and a comprehensive set of feasible refined methods for eco-concrete mix proportion design was proposed. In contrast to the empirical method, concrete designed via the subject’s methodology exhibits a marked enhancement in compressive strength while retaining favorable pore characteristics—rendering it well-suited for deployment in the slope protection of reservoirs and ponds and thereby facilitating the realization of ecological slope protection functionality. Full article

One type of pore fundamental to water dynamics is the intra-aggregate pore, which holds water vital for plant and root system development, mainly in finer-textured soils such as clays. The distribution of intra-aggregate pores also influences the redistribution of water. Thus, it is important to study the dynamics of the intra-aggregate pore network under processes such as wetting and drying cycles (WDC). Changes in these pore types can play essential roles in organic matter protection, water movement, microbial activity, and aggregate stability. To date, there are few studies analyzing the impact of WDC on intra-aggregate pore dynamics. This study aims to provide results in this regard, analyzing changes in the pore architecture of a subtropical Oxisol under no-tillage (NT), conventional tillage (CT), and forest (F) after WDC application. Three-dimensional X-Ray microtomography images of soil aggregate samples (2–4 mm) subjected to 0 and 12 WDC were analyzed. The results showed that WDC did not affect (p > 0.05) the imaged porosity, number of pores, fractal dimension, tortuosity, and pore connectivity for the different soil management types. To analyze the permeability and hydraulic conductivity of the soil pore system, the most voluminous pore (MVP) was examined. No differences were observed in the imaged porosity, fraction of aggregate occupied by the MVP, connectivity, tortuosity, hydraulic radius, permeability, and hydraulic conductivity between 0 and 12 WDC for the MVP. Comparing soil management types after 12 WDCs, for example, F samples became more porous than CT and NT samples. In contrast, the pore system of NT had a lower fractal dimension and was more tortuous than that of CT and F samples. Our results show that for highly weathered soils such as the Brazilian Oxisol studied, the intra-aggregate pore network proved resistant to changes with WDC, regardless of the type of management adopted. Full article