Search Results (883)

Lead (Pb) is a persistent and highly toxic heavy metal that poses significant ecological and human health risks due to its high bioaccumulation potential. In this study, nitrogen-doped biochar (NBC) was synthesized from straw-derived biochar via ball-milling and ammonium nitrate modification to remediate Pb-contaminated soil. Batch adsorption experiments demonstrated that the adsorption process was best described by the Langmuir isotherm model, indicating monolayer adsorption. X-ray photoelectron spectroscopy (XPS) revealed that Pb(II) immobilization by NBC occurred through multiple mechanisms, primarily precipitation and complexation with hydroxyl and pyrrolic-N functional groups. Subsequent pot experiments confirmed that NBC outperformed pristine biochar (BC) in reducing Pb bioavailability. This superior performance was attributed to the ability of NBC to increase soil pore water pH and significantly decrease soil redox potential (Eh). Moreover, compared to the control, a 5% NBC treatment (NBC2) significantly increased soil organic matter (SOM) by 136.24% while concurrently increasing soil available nitrogen (SAN), phosphorus (SAP), and potassium (SAK) by 46.91%, 75.72%, and 42.79%, respectively. Microbiological analyses indicated that NBC application enhanced soil alpha diversity (Chao1, ACE, and Shannon indices) and enriched beneficial bacterial phyla, such as Proteobacteria and Firmicutes. Random forest analysis identified the acid-soluble Pb fraction and SOM as the main drivers of bacterial operational taxonomic unit (OTU) composition. Specifically, NBC increased the relative abundance of the family Hungateiclostridiaceae, which may promote soil sulfide production and facilitate the precipitation of Pb into highly insoluble forms, further reducing its mobility and toxicity. Collectively, these findings demonstrate that NBC is a promising soil amendment that leverages both physicochemical and microbial pathways to immobilize Pb, mitigate environmental toxicity, and restore soil ecological health. Full article

To address safety issues caused by the bottom impact of the power battery in new energy vehicles, a lightweight bottom panel design scheme based on long glass fiber-reinforced polypropylene (LGF/PP) honeycomb composite was proposed. By employing the sandwich structure with an LGF/PP surface material/polypropylene honeycomb core combined with high-shear-strength structural adhesive bonding technology, ball impact protection for the power battery bottom is greatly improved. A ball striking test was carried out in accordance with the requirements and test methods of bottom anti-collision for pure electric passenger vehicles (T/CSAE 244-2021), and the performance differences of traditional steel bottom guards were compared. The results show that the optimized honeycomb composite bottom guard plate (surface thickness 1.3 mm/honeycomb core 8 mm) is able to reduce the deformation of the aluminum plate to 10.4 mm, resulting in deformation that is only 68% of that observed with the steel bottom guard plate while achieving a 43% reduction in weight. The deformation of the aluminum plate was further reduced to 42.3% with the introduction of a structural adhesive with a 5 MPa shear strength. In addition, the honeycomb structure exhibits controllable plastic deformation after impact, while the steel bottom guard plate is severely distorted but not ruptured, highlighting the damage tolerance and energy absorption advantages of the composite material design. The honeycomb composite bottom guard plate outperforms the traditional scheme in terms of light weight, protection performance and cost. This work contributes to the field of power battery bottom protection. Full article

The synergistic co-production of ceramic fibers from fly ash and coal gangue offers a promising path for their high-value utilization. However, research in this area remains limited, hindering its broader application. This study employs numerical simulations to assess the influence of high-wheel rotational speed and melt temperature on the mass of inter-wheel melt transfer, as well as their effects on ligament size and slag-ball fraction. The results show that the high wheel, responsible for melt pre-fragmentation and transfer, plays a crucial role in determining the mass of inter-wheel melt transfer and controlling ligament dimensions. In contrast, the low wheel does not directly affect ligament size but aids in transforming pre-fragmented droplets into ligaments and modulates their dispersion. Melt temperature impacts both transfer mass and ligament size by modifying melt properties. The slag-ball fraction increases with the melt temperature and decreases with the high-wheel speed, while the low-wheel speed has a negligible effect. Under the optimal operating conditions of a melt temperature of 1745 °C and equal rotational speeds of 10,000 rpm for both the high and low wheels, a ligament structure with a relatively concentrated size distribution is obtained, with the slag-ball fraction effectively controlled within the range of 8–13%. Full article

The rapid growth of electric vehicles and electrified systems has increased the risk of bearing failures due to combined mechanical and electrical stresses. This study investigated the performance of hexagonal boron nitride nanoparticle-enhanced lithium grease under electrified conditions. Experiments based on a Taguchi L9 orthogonal array were conducted on deep groove ball bearings using a full-scale test rig at 1200 rpm with varying loads (100–300 N), currents (6–10 A), and hBN concentrations (0.1–1 wt.%). The tribo-electrical performance of nano-enhanced grease was compared with the base grease and commercial grease. It was observed that the base grease exhibited superior performance with a lower current flow, reduced vibration, and minimal surface degradation. In contrast, the hBN-enhanced grease exhibited inferior tribo-performance, with high vibrations and surface damage in electrified conditions. The surface analysis revealed features morphologically similar to white etching areas and micro-pitting. The FTIR results indicated grease degradation, while ICP-OES confirmed higher wear debris generation in the commercial and hBN-added greases. The present work indicates that additives like hBN nanoparticles do not necessarily improve performance under electrified conditions, making it important to consider the type of additives to be added during lubricant formulation. Thus, the findings emphasize the importance of lubricant formulation for controlling electrically induced bearing failures and provide insights for developing advanced greases for electric machinery applications. Full article

High-entropy alloys (HEAs) are a transformative class of materials with remarkable structural and functional properties. Solid-state processing techniques, such as high-energy ball milling, are being increasingly used for their production. In these processes, the use of a process control agent (PCA) seems to be essential to prevent excessive cold welding and agglomeration; however, the influence of different PCAs on alloy formation remains insufficiently understood. This study systematically examined the effects of the PCA type, milling configuration, and elemental substitution on HEAs mechanosynthesis. A non-equiatomic alloy, Al₁₀Cr₁₂Fe₃₅Mn₂₃Ni₂₀ (selected for its known single-phase Face Center Cubic (FCC) behavior), was used to explore the PCA and mill-type effects. The alloy was synthesized in a planetary mill (Fritsch Pulverisette 7) and a vibratory mill (SPEX 8000M) using diverse PCAs, including liquid (methanol, ethanol, isopropyl, and n-heptane) and solid (stearic acid and sodium chloride) agents. In addition, lightweight equiatomic alloys MgAlTiNi(Co,Cr,Fe) were used to explore the influence of different PCAs and the effect of elemental substitution under similar PCA conditions as those used with the equiatomic alloy. The products were characterized using X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, and differential thermal analysis techniques. The results highlighted that the PCA selection, milling configuration, and alloy chemistry influenced the phase evolution, particle size distribution, and thermal behavior. The results provide insights into the mechanosynthesis of selected high-entropy alloys produced under different PCA and milling conditions. Full article

This paper introduces an adaptive fixed-time position controller (AFxTPC) designed for the lifting axis servo mechanism of a computer numerical control (CNC) plasma machine. It integrates a permanent magnet synchronous motor, gearbox, and ball screw into a unified electromechanical model. The proposed AFxTPC combines a fixed-time terminal sliding surface function with adaptive fixed-time sliding mode control to achieve fixed-time convergence, precise tracking, and robustness in the presence of parameter uncertainties. A specially designed reaching law guarantees accurate trajectory tracking, while the fixed-time terminal sliding surface function effectively minimizes chattering near the sliding manifold. Importantly, a novel fixed-time nonlinear disturbance observer is developed to simultaneously estimate the unmeasured system states and lumped disturbances in real time within a guaranteed initial-state-independent settling time. These estimated values are explicitly fed back into controller for active disturbance compensation. The stability of the overall closed-loop system is rigorously established using Lyapunov stability theory. Simulation results demonstrate that the proposed observer-based controller achieves superior performance compared with conventional proportional–integral–derivative (PID) and standard sliding mode controllers. It exhibits zero steady-state error, reduced overshoot, minimal chattering, and strong robustness over a wide range of operating conditions. Full article

Paralympic water polo requires classification systems that reflect sport-specific functional performance under ecologically valid conditions. This pilot study proposes a task-specific kinematic profiling framework for deriving objective, biomechanically interpretable descriptors of residual motor function. Five male national-level water polo athletes—three with eligible motor impairments and two able-bodied reference participants—performed standardized sport-specific tasks comprising upright floating, vertical propulsion, unilateral passing, non-contested shooting, and contested shooting under physical opposition. Stereoscopic video, OpenPose-based three-dimensional reconstruction, and phase-based analysis were used to extract features and composite indices of postural control, propulsion capacity, upper-limb residual function, and resistance to perturbation. Automatic ball-release detection matched manual frame-level verification in all 128 analyzed ball-related trials. Within the task-specific indices, where higher scores indicate greater functional burden, core values ranged from 0.05–0.15 for upright floating, 0.29–0.68 for combined arm-and-leg vertical propulsion, and 0.040–0.148 for contested shooting across the available subject–side combinations. The profiles showed task- and side-specific differences in stabilization, propulsion, and post-contact motor reorganization. The framework uses pose estimation as a quantitative measurement tool and treats visibility interruptions as functionally meaningful events rather than noise. It is not intended to replace official classification procedures, but to provide transparent and interpretable candidate descriptors for future evidence-based classification research in Paralympic water polo. Full article

Introduction: Cryoablation is an established nephron-sparing option for small renal masses, particularly in patients unsuitable for surgery. However, definitive histopathological assessment post-ablation is limited due to the in situ nature of treatment. This report details a case of delayed partial nephrectomy after cryoablation, enabling comprehensive histopathological evaluation of long-term treatment effects. Case presentation: A 50-year-old man with uncontrolled hypertension, diabetes, and triple-vessel coronary disease presented with a 2.5 cm right renal mass. Cardiovascular instability deferred initial surgery. Following coronary intervention requiring anticoagulation, percutaneous cryoablation was performed using CT-guided 3D reconstruction for precise probe placement and ice-ball confirmation. After 388 days, laparoscopic partial nephrectomy was performed. Histopathology revealed a 1.9 cm clear cell renal cell carcinoma. Approximately one-third of tissue showed post-cryoablation changes. Three distinct zones were identified: viable carcinoma, coagulative necrosis with preserved glomerular outlines, and viable parenchyma. Serial follow-up over 2 years showed transient creatinine elevation normalizing by 3 months, with no recurrence or metastasis. Conclusions: This case provides rare whole-lesion histopathological assessment after renal cryoablation, illustrating heterogeneous long-term tissue response and supporting cryoablation as a disease-control or bridging strategy in medically high-risk patients. Full article

Based on outer raceway control theory and a five-degree-of-freedom quasi-static model of angular contact ball bearings, a raceway wear model considering curvature radius variation is proposed, which couples the quasi-static model with a modified Archard wear formulation and a dynamic curvature radius update mechanism. As wear accumulates, the worn curvature radii are fed back into the quasi-static model to recalculate the raceway contact dynamic parameters. Taking the SKF 7012ACE/HCP4A spindle bearing as an example, the wear depth evolution and the variations of contact ellipse area, contact stress, sliding velocity, and wear coefficient with wear time are investigated under combined loads. The results indicate that as wear progresses, the raceway curvature radii increase, leading to a decrease in contact ellipse area but an increase in contact stress and sliding velocity, which in turn accelerates the wear process. The findings demonstrate that the degradation of raceway curvature radius has a cumulative and non-negligible influence on wear evolution and should be incorporated into bearing wear calculations for more accurate life prediction. Full article

Handball requires athletes to sustain intermittent high-intensity effort while maintaining rapid cognitive processing and technical skills. Caffeine is widely used as an ergogenic aid, yet its dose-dependent effects across physical, cognitive, and technical performance outcomes remain unclear in female handball players. This randomized, double-blind, placebo-controlled crossover study examined the acute effects of low-dose caffeine (LCAF; 3 mg/kg), moderate-dose caffeine (MCAF; 6 mg/kg), and placebo (PLA) in trained female handball players. Participants (n = 20) completed three experimental sessions separated by 72 h. Cognitive performance was assessed using the Simplified Eriksen Flanker Test, throwing performance was evaluated through maximal ball velocity, and intermittent running capacity was measured with the Yo-Yo Intermittent Recovery Test Level 1. Both LCAF and MCAF significantly improved Yo-Yo performance compared with PLA (η²p = 0.415, representing improvements of approximately ~23.5% and 29.0%), with no difference between caffeine doses. MCAF significantly reduced overall Flanker response time (η²p = 0.486, ~18.5%) and congruent and incongruent trial response time compared with PLA and LCAF. No significant effects were observed for throwing velocity, Flanker accuracy and interference scores. These findings suggest that acute caffeine intake has performance-specific effects in female handball players: intermittent running performance responded to both doses, whereas cognitive enhancement was limited to response time, with no improvements in inhibitory control or accuracy. Full article

Magnesium hydroxide is attracting growing interest as a versatile, halogen-free flame retardant, and this review surveys its production routes, structure–property relationships and use in polymer systems from commodity polyolefins to advanced bio-based materials. Industrial Mg(OH)₂ is still predominantly obtained from mining or hydration of MgO, but increasing attention is being devoted to recovery from seawater and saltwork brines, where precipitation from Mg²⁺-rich streams followed by controlled rehydration or direct precipitation yields fine, high-purity powders suitable for flame retardant use and simultaneously valorizes saline wastes. In parallel, hydrothermal synthesis has been extensively explored to tailor particle size and morphology by adjusting the precursor, solvent, temperature and time, enabling high-surface-area Mg(OH)₂ or MgO with narrow size distributions that are attractive for high-performance composites also evaluated via ball milling, crushing and refining. More recently, process intensification strategies such as microwaves and ultrasounds have been proposed to shorten reaction times, lower temperatures and better control nucleation and growth, opening paths toward energy efficient production of structured Mg(OH)₂ from both conventional and brine-derived precursors. The second part of the review analyzes how the intrinsic endothermic decomposition and basic character of Mg(OH)₂ can be utilized across a broad range of polymer matrices and how surface functionalization strategies extend its applicability. In addition to “as received” powders, stearic acid and other fatty acids, metal soaps and various organic coupling agents are widely used to render the surface more hydrophobic, enhance dispersion and interfacial adhesion, and in some cases introduce additional char-forming or barrier functionality. In terms of the application, the review methodically synthesizes and contrasts fire and mechanical data for Mg(OH)₂-containing polyolefins (HDPE, LLDPE, PP and EVA) utilized in cables and building products, expandable polymers and foams, biopolymers (PLA and PBS), and elastomers. The review places particular emphasis on the balance between loading level, processability, flame performance and mechanical integrity. This review aims to provide a comprehensive framework for designing next-generation Mg(OH)₂-based flame-retardant systems for both conventional and emerging polymer technologies. To this end, it integrates advances in sustainable feedstocks, controlled synthesis and surface engineering with the rapidly expanding application space. Full article

The hydrodynamic and tribological characteristics of a sucker-rod pump valve assembly with a modified seat equipped with a turbulizer are investigated. The study aims to extend service life by controlling the flow structure and reducing contact loads in the ball–seat pair. A combined approach is employed, integrating computational fluid dynamics (CFD) simulations with physical experiments. The results show that an increase in turbulence intensity does not lead to a proportional improvement in performance due to energy dissipation; however, an optimal turbulizer geometry is identified that ensures directed swirl flow and efficient transfer of angular momentum. It is established that the theoretical number of ball rotations in oil is 24 over 5 s, whereas the experiment conducted in water yields 30 rotations over the same period, which is attributed to viscosity effects. An empirical relationship is proposed to describe transitions between the “free flow,” “flow with ball,” and “turbulized flow” regimes, taking into account the rheological properties of the fluid; the validity of the model is confirmed by computational experiments. It is demonstrated that reducing contact forces is a more critical factor than maximizing hydraulic efficiency. Full article

Autism spectrum disorder is heterogeneous across clinical presentation, cognition, development, and biological profile. This heterogeneity complicates multimodal phenotyping when measurements are grouped in different modality blocks: Some blocks are missing, and deployment sites differ from training sites. We introduce a hierarchical latent-summary framework for multimodal autism phenotyping under incomplete observation and domain shift. The model separates a shared global latent summary from block-specific latent summaries. It makes block configurations, missingness patterns, and domain labels explicit. Under compactness, continuity, coupling observability, and inverse-stability assumptions, recovered summaries are well defined, and the error in the global summary can be bounded. This error control propagates to block-specific summaries under Lipschitz coupling maps. Domain variation is handled through a Wasserstein risk envelope in recovered latent-summary space. The guarantee is conditional on the deployment distribution lying inside the prescribed Wasserstein ball. Empirical evaluation has two complementary roles. Two synthetic studies test the structural mechanisms predicted by the theory: The first shows the asymmetric block value, nonuniform missing-block degradation, and a near tie between the full block set and a stable reduced configuration; the second separates practical train-only radius calibration from a certified transport construction. A real-data clinical illustration using the Autism Brain Imaging Data Exchange (ABIDE) phenotypic and preprocessed imaging-derived variables then examines whether the cross-sectional surrogate exposes analogous block-structured phenomena in a multisite autism cohort after excluding direct diagnostic symptom instruments. This illustration shows modest site-held-out diagnostic signals, clear block asymmetry, substantial site-level instability, and limited degradation under moderate additional block removal. These findings support a block-structured view of multimodal autism phenotyping in which prediction, missingness, latent recovery, and transportability must be evaluated jointly. Full article

Accurate fault diagnosis of rotating machinery is critical for ensuring the reliability of the energy, industrial, and transportation sectors. However, conventional methods face significant challenges, including the susceptibility of the Snow Ablation Optimizer (SAO) to local optima, the instability of Multiscale Differential Symbolic Entropy (MDSE) with short time series, and the non-adaptability of Support Vector Machine parameters. To address these issues, this study proposes a parameter-adaptive fault diagnosis framework integrating an improved SAO with Adaptive Refined Composite Multiscale Differential Symbolic Entropy (Adaptive-RCMDSE). First, the Logistic Sine Cosine strategy (LSC) is introduced to enhance SAO’s global search capability, forming the LSC-SAO algorithm. Subsequently, an Adaptive-RCMDSE method is developed wherein LSC-SAO optimizes the control parameter to significantly improve feature stability for short time series. Furthermore, an Adaptive Support Vector Machine (Adaptive-SVM) model is constructed, employing LSC-SAO to automatically tune the penalty factor and kernel parameters for precise fault identification. Finally, validation is performed on gearbox, ball bearing, and axle box bearing datasets. Results indicate that the proposed method achieves superior diagnostic performance, with average accuracies of 99.70%, 99.29%, and 99.28%, respectively, outperforming existing methods. This work provides an effective and robust solution for intelligent health monitoring of rotating machinery. Full article

The bowling performance of cricket fast bowlers is highly dependent on lower limb power and stiffness. French Contrast Training (FCT) and Velocity-Based Training (VBT) are effective ways to improve rate of force development and peak power. The objective of this study was to investigate the effects of VBT-optimized FCT on the lower limb explosive power and bowling performance of cricket fast bowlers. Twenty adult male medium-fast bowlers volunteered for this study and were evenly divided into an experimental group (EG) and a control group (CG). The EG underwent an 8-week VBT-based FCT program, while the CG completed 8 weeks of traditional resistance training combined with traditional plyometric training. Before and after the intervention, subjects were tested on their Bulgarian split squat load–velocity profile, general lower limb power (countermovement jump height, squat jump height, Eccentric Utilization Ratio, and Reactive Strength Index), and bowling performance metrics (front foot contact time, peak force, impulse, front knee angle at ball release, and ball release speed). The results demonstrated that the EG showing significant advantage over the CG on movement velocity during the Bulgarian split squat at loads 20% 1RM, 40% 1RM, and 60% 1RM (p = 0.008, 0.011, 0.008, ${\eta }_p^2$ = 0.337, 0.313, 0.324). General lower limb power in the EG also improved significantly, with CMJ height, EUR, and RSI showing significant inter-group superiority compared to the CG (p < 0.001, = 0.019, 0.004, ${\eta }_p^2$ = 0.659, 0.281, 0.399). Regarding bowling performance, the EG demonstrated highly significant advantages in front foot contact impulse, front knee angle at ball release, and ball release speed (p < 0.001, ${\eta }_p^2$ = 0.572, 0.590, 0.704). In conclusion, the 8-week VBT-FCT program is more effective than the traditional resistance and plyometric training program of the same duration in enhancing lower limb power and bowling performance for medium-fast cricket bowlers. Full article