Search Results (4,762)

Ti-6Al-4V alloy exhibits excellent comprehensive mechanical properties and good corrosion resistance; however, its relatively low surface hardness and insufficient wear resistance limit its further applications in sliding contact and corrosive environments. In this study, plasma nitriding at 750 °C was employed to modify the surface of Ti-6Al-4V alloy, and the effects of plasma nitriding treatment on microstructural evolution, wear resistance, and electrochemical corrosion behavior were systematically investigated. The results indicate that a continuous nitrided layer with a thickness of approximately 2.77 µm was formed on the surface of Ti-6Al-4V alloy. The surface hardness increased from 317.60 HV for the untreated sample to 548.77 HV after plasma nitriding. Compared with the untreated sample, the average friction coefficient of the nitrided sample increased from 0.328 to 0.497; however, the maximum wear depth decreased significantly from 73.91 µm to 0.60 µm, and the wear rate decreased from 30.73 × 10⁻⁵ mm³·N⁻¹·m⁻¹ to 0.43 × 10⁻⁵ mm³·N⁻¹·m⁻¹, corresponding to a reduction of approximately 98.6%. Wear morphology analysis shows that severe ploughing grooves, adhesive tearing, and localized spalling dominated the wear mechanism of the untreated sample. In contrast, the nitrided sample exhibited significantly mitigated wear, characterized mainly by shallow grooves, slight debris accumulation, and minor localized delamination. Electrochemical measurements demonstrate that the nitrided sample exhibits a lower corrosion current density and higher impedance in NaCl solution, indicating that the nitrided layer effectively enhances the electrochemical stability of Ti-6Al-4V alloy. The improved wear and corrosion resistance of the plasma nitrided samples can be primarily attributed to the high hardness and effective surface protection provided by the continuous nitrided layer. Full article

Composite aerogels based on polytetrafluoroethylene (PTFE) and graphene oxide (GO) with a high polymer content of 90, 95 and 98 wt.% were synthesized for the first time. It was found that GO performs a structure-forming function, allowing the production of monolithic three-dimensional frameworks stable under freeze-drying conditions even at a minimal concentration of 2 wt.%, whereas pure PTFE is destroyed under these conditions. Subsequent annealing of the composites at 370 °C, which is higher than the decomposition temperature of oxygen-containing groups of GO and the melting point of PTFE, leads to the formation of PTFE/reduced graphene oxide (rGO) aerogels. A direct dependence of shrinkage during annealing on the polymer content was observed: it sharply increases from 2.1% to 26.6% with an increasing proportion of PTFE. This effect is explained by the dominant role of capillary forces pulling together the rGO sheets in the molten polymer, while the rGO frame resists the shrinkage. The most significant result is the achievement of a record low water sorption capacity (Q_w) for an aerogel with 98% PTFE, amounting to only 0.001 g/g. This value is several orders of magnitude lower than that of pure rGO aerogel (~20 g/g), confirming that a high content of hydrophobic polymer combined with thermal treatment effectively shields the hydrophilic sites on the surface of the rGO sheets. The composites obtained in this work exhibit high hydrophobicity (contact angles up to 144°) and unique potential for the selective absorption of organic solvents from water. Full article

Antimicrobial resistance is a critical global challenge that necessitates the development of durable, material-based strategies to limit pathogen survival and transmission. Conventional cleaning and disinfection methods only provide transient protection due to rapid surface re-contamination. This study investigates the fabrication of polyethylene terephthalate (PET) surfaces designed for antibacterial applications via femtosecond laser-induced micro- and nanostructuring. Surface texturing was performed using a Ti:sapphire femtosecond laser (wavelength λ = 800 nm, pulse duration τ = 70 fs) at peak laser fluences (F) of 2.04 J/cm² and 4.08 J/cm², generating hierarchical surface textures with controlled morphology, spacing, and geometry through ultrafast, non-contact laser processing while preserving the bulk properties of PET. The resulting patterns, including parallel and intersecting microchannels decorated with laser-induced nanostructures, enabled tunable surface roughness and wettability, with water contact angles ranging from 33.21° to 118.2°. Comprehensive surface characterization, including morphological, topographical, and wettability analyses, was performed to establish structure–property relationships associated with previously reported antibacterial surface design principles. However, direct antibacterial performance was not evaluated in the present study and will be the subject of future investigations. In addition, the durability of the laser-structured PET was evaluated under simulated real-life conditions, including thermal cycling, ultraviolet exposure, abrasion, chemical resistance, and dust contamination. The structured surfaces demonstrated high structural and functional stability following environmental testing. The results indicate that the laser-induced surface modifications remain stable under conditions representative of prolonged practical use, supporting their potential long-term applicability for antibacterial and self-cleaning PET surfaces. Full article

Nanomedicine-based liposomal delivery systems are gaining increasing attention as advanced therapeutic platforms for managing ocular infections associated with antimicrobial resistance (AMR) and biofilm formation. The primary objective of this review is to critically evaluate the potential of liposomal drug delivery systems for improving the treatment of antimicrobial-resistant and biofilm-associated ocular infections by integrating current knowledge on antimicrobial resistance mechanisms, biofilm-targeted therapeutic strategies, and advances in liposomal formulations, while also identifying the major limitations, translational challenges, and knowledge gaps in this rapidly evolving field. Traditional ocular antimicrobial treatments are frequently limited by poor drug penetration, short precorneal residence time, low bioavailability, systemic side effects, and inadequate activity against resistant microorganisms and biofilm-embedded pathogens. This review provides a comprehensive overview of different liposomal systems, including conventional, cationic, polyethylene glycol (PEG)-modified, deformable, and stimulus-responsive liposomes, and discusses their advantages in ophthalmic drug delivery, such as enhanced corneal permeation, prolonged drug retention, controlled release, improved biocompatibility, and reduced ocular toxicity. The review further examines the mechanisms through which liposomes help overcome AMR, including improved epithelial transport, membrane disruption, intracellular drug delivery, efflux pump evasion, and enhanced antimicrobial efficacy. In addition, liposomal approaches targeting ocular biofilms are explored, focusing on improved biofilm penetration and the delivery of anti-biofilm agents such as antibiotics, enzymes, quorum-sensing inhibitors, and antimicrobial peptides. Current evidence from in vitro and in vivo ocular infection models is summarized together with disease-specific applications in keratitis, endophthalmitis, and contact lens-related infections. The article also compares liposomes with other ocular nanocarriers and addresses important considerations related to safety, stability, sterilization, large-scale production, and regulatory translation. In addition to highlighting recent advances, this review critically discusses the current limitations of liposomal formulations, the major barriers to clinical translation, and the key knowledge gaps that should be addressed to facilitate the future development and successful clinical application of these systems. Finally, emerging directions including ligand-targeted and stimulus-responsive liposomes, AI-driven formulation development, personalized nanotherapy, and gene therapy combinations are discussed as promising future strategies for combating resistant ocular infections. Full article

To enhance the service life and operational precision of Ti-based aerospace gears, sinusoidal closed-cycle structures containing S (SnCuAg), G (Graphene), A (Al₂O₃), SG, SA and SGA are fabricated using laser additive manufacturing and high-temperature infiltration. The results reveal that SGA lubricants ensure superior synergistic lubrication. During the wear process, a substantial amount of SGA lubricants continuously exude from the sinusoidal closed structures and migrate to the contact wear interfaces, subsequently accumulating into a well-distributed lubrication film. The lubricants, S, G, A, undergo good plastic deformation, interlayer delamination and rolling friction, respectively. Hence, synergistic lubrication emerges among SG, SA, and SGA. This synergistic effect protects the wear surface and suppresses sliding-induced damage, markedly reducing the sliding resistance of mating pairs, thereby improving the anti-friction and anti-wear abilities of the film. Ultimately, Ti-SGA shows outstanding tribological behavior, achieving a friction coefficient of approximately 0.26 and a wear rate of approximately 2.73 × 10⁻⁴ mm³N⁻¹m⁻¹. Full article

The corrosion inhibition performance of a ternary inhibitor based on alkyl phosphate esters was investigated in environments simulating geothermal CO₂ systems at 60 °C and 80 °C using AISI 1018 steel as the test material. The inhibition efficiency was evaluated using mass loss method and electrochemical techniques, including linear polarization resistance (LPR), potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). Structural and surface characterization of the samples were performed using Fourier transform infrared spectroscopy (FTIR) and intermittent contact–alternating current scanning electrochemical microscopy (IC-AC-SECM). The results demonstrated a significant reduction in the corrosion rate in the presence of the inhibitor at both investigated temperatures, accompanied by an increase in polarization resistance and a decrease in corrosion current density. Electrochemical measurements indicated that the investigated inhibitor acts as a mixed-type corrosion inhibitor. FTIR analysis supported the presence of inhibitor-related species at the steel interface, while IC-AC-SECM measurements indicated a relatively homogeneous and electrochemically protected surface under the investigated conditions. The concentration–surface-coverage relationship was close to the Langmuir-type form at 60 °C, whereas greater deviations were observed at 80 °C, together with a lower apparent adsorption parameter, suggesting temperature-dependent changes in the interfacial layer. The results demonstrate the strong corrosion-protection performance of the investigated commercial ternary inhibitor formulation under the tested conditions. Full article

Cyclodextrin (CD)-based supramolecular nanofibers (NFs) have emerged as an advanced class of multifunctional materials for active food packaging by integrating host–guest supramolecular chemistry with electrospun nanofibrous architectures. The unique hydrophobic cavity and hydrophilic exterior of CDs enable the encapsulation of a wide range of bioactive compounds, including essential oils, natural antioxidants, antimicrobials, and volatile active agents, thereby enhancing their solubility, stability, controlled release, and preservation efficacy. This review comprehensively discusses the molecular structure and inclusion complexation mechanisms of CDs, recent advances in polymer-assisted and polymer-free electrospinning strategies, and the design of CD-based supramolecular nanofibers for food preservation. Particular emphasis is placed on the relationship between fiber morphology, supramolecular interactions, and controlled release behavior, which collectively govern antimicrobial, antioxidant, moisture management, and barrier properties. Recent developments involving biodegradable polymers, hybrid nanofibrous systems, and cyclodextrin-based metal–organic frameworks (CD-MOFs) are critically summarized, highlighting their roles in improving encapsulation efficiency, mechanical stability, and multifunctional performance. The review further compares CD-based nanofibers with other advanced encapsulation technologies, including liposomes, solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions, polymeric nanoparticles, microspheres, and conventional MOFs, providing a comprehensive evaluation of their loading capacity, release kinetics, scalability, cost, and regulatory suitability for food-contact applications. Representative applications in the preservation of fruits, vegetables, meat, seafood, dairy products, and bakery products demonstrate significant improvements in microbial inhibition, oxidation resistance, ethylene and volatile organic compound adsorption, and shelf-life extension through sustained delivery of natural preservatives. Ultimately, the current challenges, including large-scale manufacturing, long-term stability, regulatory approval, and commercialization, are discussed together with future directions, focusing on smart packaging, stimuli-responsive delivery systems, intelligent sensing, biodegradable multifunctional materials, and sustainable industrial implementation. Full article

Series resistance (Rs) is a key parameter that limits photovoltaic cell performance; however, its conventional estimation from current–voltage measurements requires electrical contact and controlled testing conditions. In this study, a nondestructive image-based methodology is proposed to estimate Rs in crystalline silicon photovoltaic cells using electroluminescence images and a Sugeno-type adaptive neuro-fuzzy inference system. A dataset of 666 electroluminescence images was processed using normalized grayscale histogram descriptors, and reference Rs values were obtained from I-V characterization. Three global radiometric descriptors corresponding to low-, medium-, and high-intensity pixel fractions were used as model inputs. The ANFIS model achieved high predictive performance, with a testing RMSE of 0.0065 Ω and an R² value of >0.98. These results indicate that the global EL intensity distributions contain information related to resistive losses. However, further validation under different acquisition conditions and using independent datasets is required before field-scale deployment. The proposed approach provides a compact and interpretable framework for rapid photovoltaic cell screening based on electroluminescence imaging, complementing conventional electrical characterization under controlled laboratory conditions. Full article

Agricultural soil contact components, including ploughshares, rotary blades, and furrow openers, form the active interface between machinery and complex field media. Operating in multiphase environments, these tools face severe abrasive wear, impact fatigue, and interfacial adhesion. These destructive forces irreversibly alter edge geometry and drastically degrade macroscopic operation quality. This review integrates tillage and precision seeding components into a unified tribological framework. It highlights the nonlinear relationship between microscopic material removal and geometric edge retention. Profile degradation is heavily dictated by soil texture, where sandy soils cause micro-cutting, clay soils induce severe adhesion, and gravelly soils produce impact fracture. To predict these complex wear behaviours accurately, coupled multiphysics numerical simulation using the discrete element method for particle flow dynamics and finite element analysis for transient contact stress provides a highly robust methodology. Mitigating these failures requires a functionally zoned surface engineering approach. Carbide hardfacing offers localized abrasion resistance, while polymer composite layers and bionic nonsmooth structures effectively interrupt continuous liquid films in wet cohesive soils. Ultimately, integrating online multidimensional sensing with full life cycle digital-twin models represents the future trajectory for developing adaptive and highly durable agricultural equipment. Full article

Concrete pavement noise generated at tire–surface contact is a negative phenomenon that might be limited differently, especially by applying surface texture. To estimate the texture’s loudness, various tests are used to measure the road noise level. One of the increasingly used tests is On-board Sound Intensity (OBSI). Performing such tests enables to explore the road noise phenomenon more efficiently; however, it also enables to distinguish and compare the texture impact on the road noise level. Moreover, it might also contribute to quiet concrete pavement further development. The article presents an OBSI method application review to investigate road noise in concrete pavements considering known texturing methods. The focus is to answer how broadly the OBSI method was applied in concrete pavements regarding texture and what the main findings are. Additionally, the following review notices if complex tests considering other pavement parameters related to road noise level and safety were performed simultaneously with the OBSI measurement. Road noise on concrete pavements has been widely investigated using the OBSI method. However, this review identifies significant research gaps. The effects of customized surface texture configurations and acoustic durability remain underexplored. Furthermore, comprehensive studies are lacking. Specifically, skid resistance (measured by TWO or SRT-3 devices) should be evaluated simultaneously with OBSI levels. These measurements must be conducted under identical conditions, including the same test speed and continuous surveying. Further research in this area will fill existing knowledge gaps and clarify pavement noise generation mechanisms. Ultimately, this will enable the development of design and maintenance guidelines for low-noise concrete pavements, optimizing texturing methods, safety, and economic factors. Full article

In response to common issues with traditional automotive switches, such as poor contact of terminals, low durability, and weak vibration resistance, this paper proposes and designs a novel high-performance automotive toggle switch. Through structural design and parameter optimization, a new solution is provided to enhance the structural strength and service life of automotive electronic components. After completing three-dimensional modeling based on SolidWorks 2025, a full set of simulation analyses was carried out using ANSYS Workbench 2024 R2. After structural optimization, the maximum stress of the core valve stem decreased from 17.19 MPa to 14.877 MPa, a reduction of 13.5%; meanwhile, the fatigue life increased to 2.51 times that before optimization, indicating that for polycarbonate materials, a slight reduction in stress can significantly slow the rate of component damage accumulation. The switch’s first-order natural frequency is 1171.7 Hz, and a random vibration analysis of the switch was conducted according to the industry standard ISO 16750-3:2023. Under excitations covering the entire 2000 Hz frequency range, the switch structure did not show deformation or fatigue risks caused by resonance, indirectly confirming that vibration energy density is often more concentrated at low frequencies. This study not only completes the innovative design and performance verification of the novel toggle switch but also demonstrates that the comprehensive research methods employed provide a systematic analytical approach for developing high-performance, highly reliable automotive electronic components under stringent industry standards. Full article

Protective reinforced-concrete (RC) elements designed to resist contact blast loading must reconcile high energy dissipation with material and weight efficiency. This study examines HollowHex, an RC slab architecture in which periodic hexagonal cellular voids redistribute blast-induced stresses along inclined web-walls through a Vierendeel-type framing action. A full-factorial design of experiments across web thickness, charge mass, and hexagonal cell radius was carried out with Abaqus/Explicit using a concrete-damaged-plasticity model and mass-dependent Friedlander overpressure histories calibrated to UFC 3-340-02 scaled-distance relations. A six-level mesh-convergence study with three independent fine-mesh verification runs established the residual mesh effect as regime-dependent, bounded within approximately 13% in the elastic and severe-damage regimes and approximately 18% in the transition regime. Ten surrogate-model families—linear, polynomial, kernel, ensemble, and multilayer-perceptron—were benchmarked under leave-one-out, 5-fold, and 7-fold cross-validation. The best models achieved out-of-sample R² = 0.96 for peak displacement and R² = 0.93 for a continuous damage volume ratio (DVR), with train-to-validation gaps of only 0.03 and 0.06, indicating genuine generalization on the small dataset. A direct identical-condition comparison against circular-hollow slabs of matched void area shows blast-equivalent performance across the elastic, transition, and severe damage regimes (peak displacements within 2%, damage volume ratios within 7%), positioning the hexagonal architecture as a blast penalty-free alternative whose selection can be driven by non-blast criteria. A cross-validated parametric design heatmap is provided as a screening tool within the verified envelope. The uniform loading idealization is cross-checked against the spatially resolved CONWEP model, conservative on peak displacement by a factor of approximately 3.5, while approximately damage-equivalent and the constitutive model is validated at the damage level against documented contact-explosion tests through coupled FEM–SPH simulation. The findings position HollowHex not as a universally superior geometry but as a quantitatively beneficial alternative within the service/transition design range of greatest practical interest for blast protection. Full article

A structure–property assessment of coating plaster reinforced with a low dosage (0.01 wt%) of graphene oxide (GO) was investigated to address the intrinsic mechanical and thermal limitations of gypsum in civil construction. Nanocomposite specimens were characterized in terms of hydration kinetics (setting time), wettability (water contact angle), and compressive behavior across a range of post-fabrication thermal treatments at 200 °C, 250 °C, and 300 °C. Although the incorporation of 0.01 wt% GO maintained the ultimate compressive strength of the matrix (~13.8 MPa), it fundamentally transformed the pre-yield behavior, doubling the initial structural stiffness (slope) from 8.7 to 18.7 MPa·mm⁻¹. This mechanical enhancement suggests the role of GO as a structural anchor capable of bridging micro-voids and restricting microcrack propagation. Beyond 200 °C, phase transformation via gypsum dehydration into basanite and anhydrite phases, validated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), led to a severe reduction in compressive strength for both neat and reinforced matrices. Crucially, however, the GO-reinforced composites retained a 76% higher structural stiffness compared to the neat plaster within this post-thermal regime. Additionally, thermal activation at 200 °C induced a critical surface modification, elevating the water contact angle to 68.1° because of partial GO thermal reduction, as confirmed by coupled TG/FTIR analysis. These findings demonstrate that while GO does not suppress the intrinsic chemical dehydration of the calcium sulfate matrix, it provides vital mechanical stabilization to the crystalline network, significantly enhancing rigidity and deformation resistance under severe thermal stress. Full article

This retrospective study is intended to contribute to the ongoing investigations of antimicrobial resistance in companion animals by specifically examining the demographics, sex, rates of resistance, and multidrug resistance of bacteria isolated from urine samples of cats and dogs suspected of urinary tract infections (UTIs) in Arizona, USA, between 2018 and 2023. Escherichia coli was the most isolated bacterium with an overall frequency of 43.4%, followed by Enterococcus faecalis (11.5%), Proteus mirabilis (10.7%), Staphylococcus pseudintermedius (9.9%), Enterococcus faecium (6.9%), and Klebsiella pneumoniae (6.3%). Each year, culture-positive canine urine samples were more frequent than positive feline samples, with summer months producing the majority of suspected UTI samples for dogs and cats. Age played a role for culture-positive urine samples only in female dogs, with no association between age or sex and the number of positive feline samples. Feline Escherichia coli and Klebsiella pneumoniae isolates demonstrated more resistance to penicillins + beta-lactamase inhibitors than canines. The feline Enterococcus faecalis isolates also revealed significantly more resistance than canine isolates to penicillins + beta-lactamase inhibitors. In terms of multidrug resistance, a significant difference was found between the isolates of both Klebsiella pneumoniae and Proteus mirabilis and other bacterial species. These findings contribute to the relevant role antimicrobial surveillance plays in the prevention and control of UTI pathogens in companion animals. Because dogs and cats often are in close contact with their owners, they may be potential sources for human infection and a One Health concern. Full article

Relatively low-cost titanium carbide (TiC) materials and metal matrix composites (MMC) are proposed for waste-to-hydrogen conversion. Two types of steels are used as bases prepared from EN 10088 flat products, namely X2CrTi12 (1.4512, AISI 409) and X5CrNi18-10 (1.4301, AISI 304). TiC is mixed with TRIBALOY^® T-800 alloy in powder form and applied via laser-directed energy deposition (DED-LB) over the substrates. For the powder mixture, Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC) are performed. The raw materials are investigated for the processes that occur in them under heating. After the solidification of the molten mixture, grinding and polishing are performed to achieve a thin layer. The studies of the obtained MMC include interface zone assessment, hardness and Young’s modulus distribution, microstructural analysis, and visual defect evaluation. Advanced sensors for acoustic emission (AE) and Electrical Contact Resistance (ECR) provided characterization together with micro-scratch testing. The use of photoluminescence spectroscopy is proposed for the new composite materials. The electron transfer pathway can be studied with time-resolved spectroscopy. Renewable energy production by breaking down waste into hydrogen-rich syngas can be achieved through pyrolysis, followed by steam reforming and purification. The obtained novel materials show promising application solutions with increased durability, corrosion, and wear resistance. Full article