Search Results (2,324)

Carbon steel components used in aluminum alloy casting are prone to severe corrosion by molten aluminum, which significantly shortens their service life. To address this limitation, protective coatings were applied to improve corrosion resistance and extend durability. In this study, laser-clad TiB₂–TiC reinforced ferroboron coatings were fabricated on carbon steel substrates. The microstructure, phase composition, and interface characteristics were systematically analyzed. Electrochemical and immersion tests were conducted to evaluate corrosion resistance in molten aluminum. The results demonstrate that the composite coating forms a dense barrier layer that effectively prevents aluminum infiltration and suppresses intermetallic compound growth. Consequently, the coated carbon steel exhibits markedly enhanced resistance to molten aluminum attack, providing a promising solution for extending the lifetime of steel components in aluminum alloy casting environments. Full article

Monitoring trace metals in commercially important fish species provides an early warning of anthropogenic contamination and potential risk to consumers. This study semi-quantified and quantified essential, non-essential, and toxic elements in the muscle of wild meagre (Argyrosomus regius) captured in the Tagus estuary (Portugal), which is used as a nursery and spawning aggregation area. Dry muscle was microwave-digested and analyzed using inductively coupled plasma –optical emission spectroscopy. Semi-quantified screening detected Al, B, Ca, Fe, K, Mg, Na, P, S, Si, Sr, and Ti, and eight elements were determined using multielement calibration (As, Cr, Cu, Hg, Mn, Ni, Se, and Zn); Cd, Pb (toxic elements), Co, and Mo were not detected in this study. Arsenic was detected in all individuals, with a minimum value of 0.348 mg/kg wet weight. A mercury level above the European Commission regulatory limit (0.5 mg/kg wet weight) was only detected in one individual, corresponding to 2% of the samples. Although other metals remain well below regulatory limits, continued biomonitoring is recommended to track temporal trends and safeguard seafood safety in transitional coastal systems, which is important for commercially relevant fish species. Full article

A composite dual-cavity passively mode-locked fiber laser based on a functionalized microsphere resonator is proposed and experimentally demonstrated. The nonlinear response of the resonator is enhanced by depositing TiO₂ film on a SiO₂ microsphere, which leads to improved mode-locking performance. The wavelength selectivity and optical field confinement of the microsphere resonator are exploited, allowing it to simultaneously serve as an intracavity narrowband filter and a nonlinear modulation element. The threshold of the mode-locked laser was measured to be as low as 34 mW, and stable mode-locked operation was achieved at a pump power of 105.7 mW, with a pulse duration of 2.8 ns, a repetition rate of 13.88 MHz, and a signal-to-noise ratio of 74.86 dB. The output spectrum exhibited a central wavelength of 1560.12 nm, a 3 dB linewidth of 0.06 nm, and a side-mode suppression ratio of 55.13 dB. This straightforward design provides an effective approach for the miniaturization of passively mode-locked fiber lasers. Full article

In this work, we have used the bubble template solvothermal method to prepare TiO₂ Hollow Spheres (THS) for in situ growth of WS₂ on their surfaces and a three-phase TiO₂ Hollow Spheres/WS₂ (THS/WS₂) heterostructure composite. We also investigated the influence of W/Ti molar ratio on the morphology, structure, and optical properties of the delaminated THS/WS₂ composite and studied its photocatalytic activity to degrade RhB in visible light. Experiment result expresses that THS/WS₂-0.20 material shows the best photocatalytic activity, which is 3.9 times higher than that of THS alone. On this basis, the process of photogenerated charge carriers and photocatalytic charge transfer on the surface of the delaminated THS/WS₂ composite was elucidated, which provides a technical support for the fabrication and research of the mechanism of a three-dimensional TiO₂-based heterojunction photocatalyst. Full article

Knowledge distillation (KD) enables the training of lightweight yet effective models, particularly in the visual domain. Meanwhile, reinforcement learning (RL) facilitates adaptive learning through environment-driven interactions, addressing the limitations of KD in handling dynamic and complex tasks. We propose a novel two-stage framework integrating Knowledge Distillation with Reinforcement Learning (KDRL) to enhance model adaptability to complex data distributions, such as remote sensing and medical imaging. In the first stage, supervised fine-tuning guides the student model using logit and feature-based distillation. The second stage refines the model via RL, leveraging confidence-based and cluster alignment rewards while dynamically reducing reliance on task loss. By combining the strengths of supervised knowledge distillation and reinforcement learning, KDRL provides a comprehensive approach to address the dual challenges of model efficiency and domain heterogeneity. A key innovation is the introduction of auxiliary layers within the student encoder to evaluate and reward the alignment of the characteristics with the teacher’s cluster centers, promoting robust feature learning. Our framework demonstrates superior performance and computational efficiency across diverse tasks, establishing a scalable design for efficient model training. Across remote sensing benchmarks, KDRL boosts the lightweight CLIP/ViT-B-32 student to 69.51% zero-shot accuracy on AID and 80.08% on RESISC45; achieves state-of-the-art cross-modal retrieval on RSITMD with 67.44% (I→T) and 74.76% (T→I) at R@10; and improves DIOR-RSVG visual-grounding precision to 64.21% at Pr@0.9. These gains matter in real deployments by reducing missed targets and speeding analyst search on resource-constrained platforms. Full article

This study investigates the presence and distribution of second phases in continuous rheo-extrusion (CRE)-processed Al-La-Ti-B grain refiners and their effect on refining A356 Al-Si alloy. Thermodynamic calculations and microstructural characterization revealed that the main second phases include α-Al, TiAl₃, TiB₂, Al₁₁La₃, LaB₆, and Ti₂AL₂₀La, with their types evolving with varying Ti/La ratios. The CRE process effectively refined and homogenized these phases. Among the tested refiners, the addition of 0.2 wt.% Al-2.5La-1Ti-1B showed the most effective refinement for A356 alloy, achieving the smallest average α-Al grain size of 221 μm and secondary dendrite arm spacing (SDAS) of 24.62 μm. This optimal refinement corresponded to superior mechanical properties: a tensile strength of 164.52 MPa and elongation of 9.0% in the as-cast state, which were further improved to be 261.13 MPa after T6 heat treatment with elongation of 5.5%. The enhancement is attributed to La’s dual role in modifying the morphology and distribution of TiB₂ and TiAl₃ phases and acting as a surface-active element to reduce nucleation work, thereby promoting heterogeneous nucleation. This work demonstrates that the CRE process is an effective route to fabricate high-performance La-bearing refiners with engineered microstructures and reveals that optimizing the Ti/La ratio is critical for maximizing grain refinement and mechanical performance in Al-Si alloys. Full article

The main goal of this research is the preparation of mechanically and mechanochemically activated Ti/B₄C/(±Ni) composite powders, which will constitute the source of reinforcement formation in the titanium powder matrix. For this purpose, two composite powders of the Ti/B₄C/(±Ni) type were obtained in the molar ratio Ti:B₄C = 5:1 and Ti:B₄C:Ni = 6:1:1, respectively, by mechanical milling (MM) in a high-energy planetary ball mill for up to 7 h. The morphological and structural characteristics of composite powders were determined by laser particle size analysis, scanning electron microscopy with energy-dispersive X-ray spectrometry, X-ray diffraction, and differential thermal analysis. By milling for up to 7 h, a good homogenization of B₄C in the Ti matrix occurs. Also, the addition of Ni leads to new phases of formation: NiTi and TiB₂. Full article

The intrinsic limitations of Ti₃C₂T_x electrodes, specifically low interfacial charge-transfer efficiency and structural degradation in strongly acidic environments, hinder their performance in high-rate aqueous supercapacitors. Herein, we report a synergistic strategy combining nitrogen plasma surface engineering with a redox-active ascorbic acid electrolyte to optimize the electrode/electrolyte interfacial kinetics. By systematic investigation, the Ti₃C₂T_x supercapacitor obtained by a 10-min plasma duration (N10P-AA) achieved the optimal balance between activating surface sites and preserving the conductive Ti–C framework integrity. The ascorbic acid electrolyte broadened the potential window to approximately 0.7 V, and N10P-AA exhibited the lowest charge-transfer impedance and superior rate capability, retaining a relatively high Coulombic efficiency (>72%) even at a high scan rate of 10,000 mV·s⁻¹. The EIS results and kinetics analysis (b values) confirmed that the moderate plasma activation effectively promoted more surface-dominated charge storage kinetics and mitigated diffusion limitation, consistent with reduced charge-transfer resistance and a smaller Warburg slope. The XPS results revealed that the 10-min treatment suppressed detrimental oxidation during cyclings and facilitated the formation of electrochemically favorable hydroxylated surface functional groups. This work demonstrates a feasible surface electrolyte co-engineering strategy for modulating the interfacial behavior of MXene, which is of great significance for future high-efficiency aqueous electrochemical energy storage and potential biosensing applications. Full article

Industrial and domestic effluents contaminated with synthetic dyes represent a significant global environmental and public health concern, necessitating the development of efficient, cost-effective, and sustainable wastewater treatment technologies. Among various remediation strategies, activated carbon (AC) has garnered considerable attention as an effective adsorbent, owing to its high surface area, excellent porosity, and strong adsorption capacity. This review presents a comprehensive analysis of activated carbon, with a particular focus on its derivation from bamboo biomass—a renewable, abundant, and low-cost precursor. It explores the key physicochemical characteristics of bamboo-based AC, common synthesis techniques, and the role of modification strategies—particularly metal oxide doping with TiO₂, ZnO, and MoS₂—in enhancing dye removal performance. The mechanisms underlying dye remediation, including adsorption and photocatalysis, as well as the synergistic effects observed in advanced AC-based composites, are critically examined. Emphasis is placed on the degradation of commonly used textile dyes such as methylene blue (MB), rhodamine B (RhB), and reactive blue, supported by comparative analyses of efficiency, stability, and reusability across various studies. Finally, the review outlines current challenges and knowledge gaps in the field, offering perspectives on future research directions to advance the development and large-scale application of sustainable bamboo-derived activated carbon composites for effective and eco-friendly wastewater purification. Full article

Particle-reinforced aluminum matrix composites demonstrate remarkable potential for use in aerospace, precision instruments, and electronic packaging applications due to their superior specific strength, high specific stiffness, and low thermal expansion coefficient. However, increasing the reinforcement volume fraction to enhance the elastic modulus often leads to a reduction in plasticity and machining performance. This study investigates hot-pressed 27 vol.% TiB₂/2024, 15 vol.% diamond/2024, and 37 vol.% SiC/2024 composite with equivalent elastic moduli, focusing on the effects of TiB₂ particle size and T6 heat treatment on their microstructure, mechanical properties, and machining performance. The results reveal that increasing the TiB₂ particle size from 7 μm to 25 μm reduces the tensile strength from 397.1 MPa to 371.7 MPa, increases surface roughness values from 110 nm to 177 nm, but simultaneously decreases tool wear. Among the tested composites, the 27 vol.% TiB₂/2024 composite exhibits optimal interfacial bonding without Al₄C₃ formation, providing the most effective load-bearing strengthening, as well as the lowest surface roughness and minimal tool wear. Moreover, the T6 heat treatment further enhanced the tensile strength of the 27 vol.% TiB₂/2024 composite from 397.1 MPa to 421.7 MPa, while reducing the surface roughness values during turning from 110 nm to 79 nm and further minimizing tool wear, thus achieving outstanding overall mechanical and machining performance. Full article

A multiscale model is developed to investigate the mechanical behavior and failure of in situ particle reinforced titanium matrix composites (PTMCs). Through the microstructural observation of the heterogeneous microscopic and mesoscopic structures in the in situ TiB/Ti55531 composites, multiscale heterogeneous models coupled to the finite element method are employed to simulate the mechanical behaviors and failures. In the atomic scale, molecular dynamics (MD) simulations are applied to determine the traction-separation (T-S) responses of the cohesive zone model (CZM) describing the Ti/TiB interface. Then, the mesoscale representative volume element (RVE) model with heterogeneous structure, including the Ti55531 matrix, the TiB particles, and their interfaces represented by the parameterized CZM, is established. The volume fraction and distribution morphology of TiB particles result from the microstructural analysis of titanium matrix composites. The simulation results show that the Young’s modulus, tensile strength and elongation of multiscale are in excellent agreement with experimental results. The stress transfer, damage evolution and fracture behavior of the TiB particles in the composites are also analyzed using this multiscale approach. Full article

Three processes for the production of ceramics close to stoichiometric MgAl₂O₄ are benchmarked against each other. The traditional ceramic route is based on mostly crystalline starting powder, which is converted into ceramic via shaping and heat treatment (IKTS). The other two processes are based on glasses. Partial or complete crystallization without pressure (ISC) or complete crystallization with pressure (CAU) leads to (glass) ceramics. Spinel powder is mixed with various dopants (BaO, TiO₂, CaO and SrO), with the aim to reduce the grain size (IKTS). The doping results in a second, partly interfering phase, and the transmission decreases strongly due to absorption with increasing content of the added oxide. For the glass route without pressure (ISC), it is shown that a network-forming oxide (B₂O₃, TiO₂) is needed to produce the glasses. Compared to the starting glasses, the resultant glass ceramics suffer loss of transparency due to crystallization. Using the levitation furnace, it is possible to produce amorphous glass beads from MgAl₂O₄ enriched with 25 wt% SiO₂ without a container. The nanocrystalline ceramics synthesized from these glasses and the ISC glasses via the high-pressure route (CAU) are moderately transparent to translucent. Full article

Educational videos contain long periods of visual redundancy, where only a few frames convey meaningful instructional information. Conventional video models, which are designed for dynamic scenes, often fail to capture these subtle pedagogical transitions. We introduce LEARNet, an entropy-aware framework that models educational video understanding as the extraction of high-information instructional content from low-entropy visual streams. LEARNet combines a Temporal Information Bottleneck (TIB) for selecting pedagogically significant keyframes with a Spatial–Semantic Decoder (SSD) that produces fine-grained annotations refined through a proposed Relational Consistency Verification Network (RCVN). This architecture enables the construction of EVUD-2M, a large-scale benchmark with multi-level semantic labels for diverse instructional formats. LEARNet achieves substantial redundancy reduction (70.2%) while maintaining high annotation fidelity (F1 = 0.89, mAP@50 = 0.88). Grounded in information-theoretic principles, LEARNet provides a scalable foundation for tasks such as lecture indexing, visual content summarization, and multimodal learning analytics. Full article

Water pollution from textile effluents poses serious environmental risks, particularly due to persistent anionic dyes such as Reactive Black 5 (RB5). This study demonstrates that simple deposition of Y₂O₃ onto commercially available, biobased TiO₂ (bTiO₂) significantly enhances photocatalytic degradation efficiency under simulated sunlight, suppressing rapid recombination of electron–hole pairs. Addressing a key research gap, the proposed method replaces expensive nanoscale precursors and complex synthesis routes typically used for Y₂O₃/TiO₂ systems with a low-cost, straightforward approach involving weak complexation and co-precipitation. The resulting Y₂O₃-bTiO₂ composite was characterized using FTIR, XRD, SEM, EDX, TEM, XPS, and UV-DRS techniques, confirming efficient incorporation of Y₂O₃ on the TiO₂ surface. Photocatalytic experiments revealed that nanoparticles calcined at 700 °C achieved complete RB5 degradation within 60 min—reducing the reaction time by half compared to undoped bTiO₂. Systematic studies of initial dye concentration, catalyst loading, and irradiation time confirmed that the degradation followed pseudo-first-order kinetics with a rate constant of 0.064 min⁻¹ (R² = 0.98). Calculated quantum yields corroborated the reduced electron–hole recombination induced by Y₂O₃ deposition. These findings highlight the novelty and practicality of the developed Y₂O₃-bTiO₂ photocatalyst as an efficient, affordable, and environmentally sustainable material for the degradation of industrial dyes. Full article

Background/Objectives: The effect of metformin combined with bone grafting materials and its effect on the hydrophilicity of different implant surfaces has not been investigated. Investigation of the use of metformin as a therapeutic for implant surface treatment may be useful in improving overall implant longevity and success. Methods: Herein, a 1.5% metformin solution was created with crystalline metformin and distilled water. Titanium alloy (machined surface), titanium with sandblasted, large-grit acid-etched surface (Ti-SLA), and zirconia (SDS) surfaces were treated with five different solutions: 0.9% sodium chloride (Group A), bovine cancellous bone graft (Bio-Oss^®)/0.9% sodium chloride solution (Group B), Bio-Oss^® bone graft with metformin/0.9% sodium chloride solution (Group C), algae-based bone graft (AlgOss^®)/0.9% sodium chloride solution (Group D), and AlgOss^® bone graft with metformin/0.9% sodium chloride solution (Group E). Hydrophilicity tests utilizing droplet angle measurements (n = 20 droplets/disk) of each of the solutions were carried out (total N = 600 contact angle measurements). Statistical comparison between treatment groups for each implant surface using ANOVA and Bonferroni correction at p < 0.05 was performed. Results: Analyses revealed a statistically significant improvement in hydrophilicity for group C compared to group B (p < 0.05) in Ti-alloy, but a significant decrease in hydrophilicity for group E compared to group D in Ti-SLA. Zirconia surfaces displayed a decrease in hydrophilicity for all groups compared to group A. Conclusions: Thus, there were varying effects of combined metformin and bone graft on implants. Full article