Search Results (520)

MXenes, with a high surface area, abundant active sites, and excellent ion transport properties, have demonstrated excellent electrochemical performance. However, systematic comparisons of the structural evolution process and electrochemical performance for MXene are lacking. In this study, multilayer MXene (M-Ti₃C₂T_x) was successfully fabricated by in situ etching. During the subsequent centrifugation process, the thicker and heavier multilayer sheets settled due to their faster sedimentation rate, while the lighter, surface-functionalized monolayer sheets remained colloidally stable in the supernatant due to solvation and electrostatic repulsion, thereby achieving separation and obtaining delaminated MXene (D-Ti₃C₂T_x). Structural analysis indicates that the removal of the aluminum layer synergizes with the exfoliation of the nanosheets, significantly increasing the interlayer spacing and making the sheet structure more pronounced, and the pore structure is more abundant. Especially, in three-electrode and two-electrode systems at an identical mass loading of 5 mg on carbon paper, D-Ti₃C₂T_x delivered a higher specific capacitance, more pronounced pseudocapacitive behavior, and a superior rate capability compared to Ti₃AlC₂ and M-Ti₃C₂T_x. Such excellent electrochemical performance of D-Ti₃C₂T_x is due to the shortened ion diffusion path in the delaminated structure, which enables rapid ion migration, an extremely large specific surface area, and a mesoporous structure that provides abundant active sites. This study underscores the significant potential of D-Ti₃C₂T_x in emerging energy storage systems and offers insights into guiding MAX phase synthesis during its preparation. Full article

The poor tribological and mechanical performance of Al alloys hinders their use in practical applications where low COF and high durability are required. This study examined and evaluated a novel laser-sintered Ni-Cr coating to improve the load-carrying capacity and tribological performance of an Al alloy (Al 6061) substrate. The authors demonstrate that laser sintering cycle count is a decisive process variable governing coating dispersion, microstructural consolidation, and tribological performance in Ni-Cr coatings fabricated via Selective Laser Sintering (SLS). Increasing the laser cycle count progressively refined the surface morphology, improved coating dispersion, and strengthened interparticle bonding. As a result, the average durability after three cycles was seven times that after one laser cycle, accompanied by markedly improved COF. To further improve durability and load-carrying capacity, Ti₃SiC₂ was introduced into the Ni-Cr coating. The coating containing 10 wt% Ti₃SiC₂ exhibited a 20-fold increase in durability, extending the time to failure to approximately 70,000 s (700 m) while maintaining a low coefficient of friction (~0.48) compared with the coating containing no Ti₃SiC₂. The greater durability of the Ni-Cr-10wt%Ti₃SiC₂ coating in this novel study was attributed to improved adhesion to the substrate, better particle distribution during sintering, and greater load-carrying capacity. While further process changes do not yield feasible samples, this study showed that surface properties can be improved within the available small-process regime. Overall, laser sintering of a Ni-Cr-10wt%Ti₃SiC₂ coating shows promise as a means to improve the tribological and mechanical performance of Al 6061. This study should aid researchers and other stakeholders in fabricating well-adhering, durable, and tribotactic composite coatings on Al6061 and similar material systems. Full article

Wind dynamics in urban environments exhibit non-stationarity and marked spatial variability, complicating stochastic modeling when a single global distribution is assumed. This article discusses the estimation of wind density under quasi-stationary regimes at the local level using SICABI, a two-phase framework: (i) Stationary Region Identification (ISR) estimates, through spectral power analysis, a specific dominant period for each location and validates the induced subsampling using the Augmented Dickey–Fuller (ADF) test, and (ii) RAPID adjusts an adaptive parametric density by recursively updating the mixture parameters and creating new components when a normalized membership distance exceeds a threshold. The analysis uses wind speed records collected from eight stations in the Metropolitan Area of Queretaro, Mexico, during the period from 1 January 2023 to 31 December 2023, aggregated at a 10 min resolution, from which $X_{\delta ,s}$ is constructed for each site. RAPID is compared against Gaussian Kernel Density Estimation (KDE) with Silverman bandwidth and EM-fitted Gaussian mixtures with BIC-based selection ($K_{max}=12$). The resulting densities were compared with an empirical density estimated from a histogram over a fixed grid ($m=50$) using the MISE and RMSE metrics. The results reveal marked site-dependent differences in dominant periodicity and residual behavior, including asymmetry and heavy tails. ISR identified dominant periods ranging from 37 to 166 days, and RAPID adapted its complexity with $K_s\in [5,10]$ without fixing the number of mixture components in advance. Quantitatively, RAPID achieved the lowest RMSE at 6/8 sites and the lowest MISE at 5/8 sites, while also exhibiting shorter execution times than KDE and MoG under the same input $X_{\delta ,s}$. The results support RAPID as a competitive adaptive method for site-specific density estimation in non-stationary urban climate signals. In this context, local regimes can be viewed as approximate invariants under time translation in the weak stochastic sense, while deviations from this assumption are reflected in increased distributional complexity across sites. Full article

Multilayer zirconias have recently been introduced as dental biomaterials to combine improved translucency with sufficient mechanical reliability by implementing yttria-driven gradients in phase composition. Such materials can be considered functionally graded ceramics, where local phase stabilization influences strength and crack resistance. However, manufacturer-specific gradient profiles and their structure–property relationships remain insufficiently characterized. This study investigated two commercially available multilayer zirconias with distinct gradient concepts: IPS e.max^® ZirCAD Prime (continuous gradient) and KATANA™ Zirconia YML (stepwise gradient). Ten equidistant sections along the blank height were analyzed using quantitative X-ray diffraction and Rietveld refinement to quantify zirconia phase fractions and estimate local Y₂O₃ content. Mechanical behavior was evaluated by biaxial flexural strength testing (ball-on-three-balls method) and fracture toughness testing using the chevron-notched beam technique. Both materials exhibited pronounced yttria- and phase-dependent gradients consistent with their reported layer designs. Regions with increased yttria content showed higher t″ fractions and reduced fracture toughness and strength, whereas deeper regions displayed increased mechanical performance associated with higher fractions of transformable tetragonal phase. These findings emphasize that multilayer zirconias exhibit spatially dependent mechanical properties, which should be considered in biomaterial selection and restoration design, particularly when balancing aesthetic demands and fracture resistance. Full article

Rising industrial demand for carbon monoxide (CO) motivates the development of sustainable pathways for its production. Composting has recently emerged as a potential biogenic CO source, yet the role of biowaste moisture in CO production has remained unquantified. In this study, the moisture dependence of CO generation during composting was assessed to address this knowledge gap. Laboratory-scale biowaste composting was conducted under mesophilic conditions (45 °C) with passive aeration for the initial 14-day phase, using three initial moisture levels: 31.6% (variant M100), 21.6% (M90), and 12.6% (M80), and periodic H₂O addition in M100 and M90. Monitoring of CO, CO₂, and O₂ concentrations, complemented by scanning electron microscopy of composts, revealed a non-monotonic moisture effect on CO formation. The intermediate-moisture treatment (M90; ~41–50%) was associated with the highest CO production, reaching a maximum of 681 ppm and 18.2 mg CO∙kg wet mass⁻¹, whereas high moisture (M100; ~51–64%) with lower CO levels (max. 276 ppm, 4.4 mg CO∙kg wet mass⁻¹), matrix compaction, elevated CO₂ and lower O₂ concentrations. The driest treatment produced trace CO (<20 ppm, max. 0.4 mg CO∙kg wet mass⁻¹) and retained a rigid, porous microstructure consistent with limited biodegradation. The results showed rapid but transient CO pulses after H₂O addition, implicating moisture-driven shifts in biological activity and/or abiotic formation. These findings identify an optimal moisture window for reproducible CO generation. Full article

Ti₂AlC, an important member of the MAX phase family, exhibits combined metallic and ceramic characteristics, showing potential for applications in conductive composites and high-temperature structural components. However, this phase possesses a narrow thermodynamic stability window, making high-purity synthesis challenging. Conventional solid-state synthesis requires temperatures exceeding 1300 °C, where aluminum volatilization and kinetic limitations of carbon diffusion lead to impurity phases such as TiC and Ti₃AlC₂. Based on the ionic transport characteristics of molten salt media, this study employed the eutectic NaCl-KCl molten salt method to synthesize Ti₂AlC using Ti, Al, and TiC powders within the temperature range of 1000–1150 °C. Systematic investigations revealed that an optimized raw powder composition (Ti:Al:TiC = 1:1.10:0.95) at 1100 °C yielded Ti₂AlC powders with 96.1% phase purity, high crystallinity, and typical laminated structure with stable stoichiometry (Ti/Al ≈ 2:1). Furthermore, Ag/Ti₂AlC composites demonstrated excellent electrical conductivity (resistivity of 5.72 μΩ·cm) and favorable mechanical properties, validating the applicability of this synthetic route for conductive composite materials. Full article

In response to escalating global environmental challenges, mitigating carbon emissions in the construction sector has emerged as a critical strategy for addressing climate change. As reported by the United Nations Environment Programme (UNEP) and the International Energy Agency (IEA), the construction industry remains a major contributor to global greenhouse gas emissions. This study investigates the influencing factors and optimization pathways for embodied carbon emissions during the materialization phase of prefabricated buildings. Through longitudinal field research at a large-scale precast component factory in western China, key carbon emission factors were identified using Min–Max normalization and Principal-Components Analysis (PCA). A cloud entropy–based evaluation model was further developed to quantify the emission weights of 32 factors. The results reveal the existence of ‘leveraging effects’ among emission factors, wherein certain low-weight factors exert disproportionate influence on systemic carbon reduction because of their cascading impacts on other variables. Prioritizing factors with greater leveraging potential is imperative for the formulation of effective emission reduction policies. This study leverages NK model simulations (10,000 iterations), to predict the reduction potential of each factor and identifies four indicators with the most significant leveraging effects. Strategic recommendations are proposed that emphasize a synergistic approach that integrates direct emission control and indirect cascading optimization. These findings provide actionable insights for achieving systemic carbon reduction in prefabricated building systems. Full article

This two-step design used the unilateral bench press to examine the effect of breast cancer surgery on upper-limb muscle activation under low and moderate fatigue conditions. First, we studied the proper method to normalize the activation values obtained during dynamic contractions. For that, the muscle activation was relativized to the maximal value obtained during (i) an isometric contraction (ISO_Norm), and the concentric phase of the (ii) repetition maximum load (1RM_Norm), and (iii) the first three repetitions of an 80% 1RM set (Max80%_Norm). The normalization method with the lowest inter-subject variability was further used to compare the muscle activation of the affected and non-affected sides of twelve women who underwent unilateral breast surgery (eight mastectomies and four lumpectomies). Both sides were tested using dynamic sets at 60 and 80% of their 1RM until reaching 40% velocity loss (VL). Repetitions completed at each %1RM were then divided into two groups: low fatigue (first half of repetitions) and moderate fatigue (second half of repetitions). On results, the ISO_Norm and the Max80%_Norm showed the highest (mean CV = 32.9%) and lowest (mean CV = 12.9%) inter-subject variability, respectively. The affected side showed higher activation for the deltoid and triceps (Δ = 6.9 to 15.9%) but lower for the pectoralis (Δ = −5.7 to −13.2%) against 60% 1RM. These differences were lower and without a consistent trend against 80% 1RM. Between-side comparisons were not significant for either 60% 1RM (p > 0.270) or 80% 1RM (p > 0.500). Although these results should be interpreted with caution due to the small and heterogeneous sample, our analyses did not reveal meaningful differences in upper-limb muscle activation following breast cancer surgery. Full article

Enhancing grain orientation along the <001> crystal axis in AlNiCo alloys is crucial for developing high-performance permanent magnets. Traditional directional solidification, known as the “cold plate-hot mold” method, is constrained by a low thermal gradient, leading to inadequate microstructural uniformity and crystallographic alignment, which impedes the optimization of magnetic properties. In this study, we employed a high-speed solidification process with an enhanced cooling gradient to fabricate AlNiCo magnets at various withdrawal rates. The variation in drawing rate influenced grain orientation within the alloy, thereby altering the degree of alignment of the ferromagnetic α1 phase following subsequent heat treatment, which ultimately affected the magnetic properties. The optimal magnetic performance was attained at a withdrawal rate of 50 μm/s, where the sample exhibited the most favorable oriented microstructure, with a remanence (B_r) of 10.62 kGs, intrinsic coercivity (H_cj) of 1.794 kOe, and a maximum energy product (BH)_max of 10.93 MGOe. Moreover, magnets at different positions exhibit excellent consistency in magnetic properties, enhancing the material utilization efficiency. This research provides valuable process parameters and a foundational basis for developing high-performance AlNiCo alloys. Full article

The dominant pores governing methane adsorption in coal are micropores (pore size < 2 nm). Their spatial heterogeneity can be quantitatively characterized using multifractal theory; however, the evolution patterns and mechanisms of microporous structures across different coalification degrees remain unclear. This research selected a series of coal samples from different ranks and identified the coalification degree using the maximum vitrinite reflectance (Rₒ_,max). By comprehensively employing low-temperature CO₂ adsorption experiments and multifractal analysis, the evolution patterns of the microporous structures and their multifractal spectral parameters were systematically revealed, and the underlying control mechanisms were explored. Results indicate that micropore volume (PV) and specific surface area (SSA) first exhibit a decrease and then increase as Rₒ_,max increases, with the trough occurring during the second coalification jump at Rₒ_,max = 1.2–1.4%. The pore sizes exhibit bimodal distributions, with the primary peak occurring in the range of 0.45–0.65 nm and the secondary peak occurring in the range of 0.8–0.9 nm. All microporous structures possess pronounced multifractal characteristics. The generalized dimension spectrum width (ΔD) and singularity spectrum width (Δα) exhibit an increasing–decreasing–increasing trend with Rₒ_,max, whereas the Hurst exponent (H) follows an inverted parabolic curve, first increases then decreases. This contrasts with the trends in PV and SSA, indicating that the evolution of pore-space heterogeneity and connectivity is independent of and lags the changes in micropore quantity. These patterns are governed by a structural phase transition within the coal macromolecular network. Marked by the second coalification jump, the microporous system shifts from a flexible degradation–polycondensation paradigm to a rigid ordering–construction paradigm. This transition drives the asynchronous, synergistic evolutions of pore quantity, spatial heterogeneity (ΔD and Δα), and topological connectivity (H). This research provides a theoretical basis for quantitatively evaluating pore heterogeneity in coal reservoirs. Full article

This comparative study investigates binder-free binary WC-TiC and ternary WC-TiC-TaC carbide ceramics as alternatives to cobalt-bonded hard materials. Equimolar compositions were processed via high-energy ball milling (HEBM) and consolidated by spark plasma sintering (SPS) at 1700–2100 °C. X-ray diffraction analysis (XRD) revealed fundamentally different homogenization kinetics: the ternary system achieved a complete single-phase structure at 2000 °C, 100 °C earlier than the binary system. This acceleration correlates with finer initial particle size (2–5 μm vs. 3–10 μm) and near-stoichiometric TaC, facilitating interdiffusion. Lattice parameter evolution confirmed the formation of (W,Ti)C and (W,Ti,Ta)C substitutional solid solutions. Mechanical characterization showed contrasting behaviors: binary WC-TiC exhibits maximum hardness at 1900 °C (1793 HV30, fracture toughness 5.07 MPa·m^1/2), while ternary WC-TiC-TaC peaks at 1700–1800 °C (1947–1782 HV30) with higher toughness (max 5.42 MPa·m^1/2). Optimal processing windows with acceptable property uniformity are 1800–1900 °C (binary) and 1700–1900 °C (ternary). The binary system offers superior toughness and stability; the ternary system enables faster processing and higher initial hardness, defining distinct application domains. Full article

Freight-dominant port collection and distribution road networks exhibit strong spatial congestion, early spillback, and heterogeneous vehicle dynamics that challenge conventional traffic signal control strategies. Although Max-Pressure (MP) signal control provides strong decentralized stability properties, its classical queue-based formulation lacks sensitivity to incipient spatial congestion and performs poorly when heavy-duty vehicles (HDVs) dominate traffic composition. This paper proposes a gain-modulated Max-Pressure (Gain-MP) control framework, in which conventional pressure computation is augmented by an occupancy-dependent feedback gain that dynamically adjusts phase priorities according to real-time spatial congestion states and current right-of-way conditions. Without altering the decentralized structure of MP, the proposed method introduces a nonlinear feedback mechanism that enhances system responsiveness to congestion formation while suppressing excessive phase switching. The approach is evaluated using microscopic simulation on a signalized grid network representing port access corridors under time-varying demand and high HDV penetration. Results demonstrate that the dynamic Gain-MP controller performs better than classical queue-based MP, PCU-weighted MP, and fixed-time control. Moreover, constant-demand experiments indicate that the dynamic Gain-MP controller maintains bounded vehicle accumulation over a wider empirical demand range than the benchmark MP-based methods under the tested settings. Full article

Background/Objectives: Recent guidelines have emphasized the importance of early mobilization and rehabilitation of patients following cardiac surgery. However, studies on the optimal targets and prescription methods for phase I cardiac rehabilitation (CR) are lacking. This study aimed to evaluate the feasibility and utility of an early phase 1 submaximal cardiopulmonary exercise test (CPET) using a recumbent ergometer in patients who have undergone cardiac surgery. Methods: Twenty ambulatory patients who underwent cardiac surgery between December 2021 and February 2023 were referred to the CR department on the fifth postoperative day, and a CR program was initiated. The program was conducted five times a week, with hour-long sessions consisting of warm-up exercises, resistance training, aerobic exercises, and a cool-down period. A recumbent ergometer-based submaximal CPET was performed approximately nine days after the surgery, prior to discharge. Participants initiated the test at 0 W, and the workload was increased by 20 W after 2 min. During the test, researchers evaluated parameters including submaximal peak values of oxygen consumption (VO₂), metabolic equivalents of task, respiratory exchange ratio (RER), blood pressure, heart rate (HR), and rating of perceived exertion (RPE). The grip strength test, 6 min walk test (6MWT), Korean Activity Scale/Index (KASI), EuroQol-5 dimension (EQ-5D), and short-form 36-item health survey (SF-36) values were also measured prior to discharge. Results: Twenty patients (75% male, average age 62.50 ± 1.99 years) underwent CPET at a median of 9.0 (8.0; 12.5) days postoperative. The average exercise duration of the CPET was 411.75 ± 168.25 s. During the test, their submaximal peak VO₂ was 12.32 ± 0.75 mL/kg/min (corresponding to 46.65 ± 2.08% of VO₂ max). The submaximal peak RER was 1.01 (0.98–1.12), and the submaximal peak RPE was 15.00 ± 0.51. Furthermore, the submaximal peak HR was 111.8 ± 3.76 beats/min (equivalent to 70.95 ± 2.09% of age-predicted maximal HR). After adjustment for age and sex, statistically significant positive correlations were observed between the submaximal peak VO₂ and 6MWT, squat endurance test, KASI, EQ-5D, and the physical component summary (PCS) of the SF-36 questionnaire. The 6MWT, squat endurance test, KASI, and PCS of SF-36 showed a correlation coefficient (r) of 0.522 (p = 0.026), 0.628 (p = 0.005), 0.586 (p = 0.011), and 0.546 (p = 0.019), respectively. No significant cardiac events, such as ST elevation/depression or hemodynamic instability, were observed during the test. Conclusions: Our findings suggest that performing recumbent ergometer-based CPET during early phase 1 CR is safe and feasible. These results highlight the potential of recumbent ergometer-based CPET as a valuable tool for guiding the appropriate prescription of early CR programs following hospital discharge in patients undergoing cardiac surgery. Full article

Fascioloidosis is a parasitic disease caused by allochthonous parasite Fascioloides magna. In Europe, three types of final hosts are recognised: definitive, aberrant, and dead end. Several countries have launched disease control programmes using medicated feed, with different drugs, to control F. magna infections. In this study, we used corn treated with Albix^® 10 in a total dose of 60 mg/kg of body weight for five consecutive days (12 mg/kg per day). Following successful treatment, a destroyed pseudocyst with different amounts of degrading material and decaying flukes was detected. A total of 136 livers was examined. The average number of pseudocysts per positive liver was seven (min. 1–max. 45), while the average number of adult flukes was 14.17 (2–70). On average, 1.34 juvenile flukes in the migratory phase were detected per infected liver. The average number of pseudocysts was 7.07 per liver in total. Degrading pseudocysts were either absent or present to a maximum of 120 per liver, with an average of 7.99 per liver. Some livers had multifocal to confluent nodules bulging from the liver parenchyma, which were up to 7 cm in diameter. Histologically, these areas showed disruption, containing bands of fibrous connective tissue, dividing parenchyma into pseudolobules of varying size and shape. These septa contained dark brown to black pigment (iron porphyrin), along with remnants of elliptical, operculated, mainly empty trematode eggs. Nodules were surrounded with fibrous tissue and disorganised hyperplastic hepatocytes arranged in irregular trabeculae supported by fibrous bands occasionally containing blood vessels. This study shows the potential of liver regeneration in the case of acute and chronic liver injury, as well as in cases of fatty liver disease. Full article

Improving absolute accuracy in industrial manipulators remains difficult because rigid-body kinematic calibration cannot fully represent configuration-dependent non-geometric effects. Drawing inspiration from biological brain–body co-adaptation, this study presents an Evolutionary Neuro-Physical Hybrid (Evo-NPH) framework in which rigid geometric parameters and neural compensator weights are treated as a single co-evolving decision vector. In the offline phase, a Dual-Strategy Adaptive Differential Evolution (DS-ADE) optimizer performs global joint identification using complementary exploration–exploitation behaviors and success-history inheritance, analogous to morphology-control co-evolution in biological systems. In the online phase, a Neuro-Physical Hybrid Jacobian (NPHJ) solver augments the analytical Jacobian with gradients from a Graph Kolmogorov–Arnold Network (GKAN), enabling sensorimotor-like real-time compensation on the learned physical manifold. Experiments on an ABB IRB 120 manipulator with 600 configurations (500 training, 100 testing) report a testing distance-residual RMSE of 0.62 mm, STD of 0.59 mm, and MAX of 0.83 mm. Relative to the uncalibrated baseline, RMSE is reduced by 86.75%; compared with the strongest published baseline, RMSE improves by 23.46%. Ablation results show that joint DS-ADE optimization outperforms a sequential pipeline by 32.6%, and the graph-structured KAN outperforms a parameter-matched MLP by 26.2%. Wilcoxon signed-rank tests ($p<0.001$) confirm statistical significance. Full article