Search Results (223)

Modeling the structure not only of whole metal products, but also of the protective coatings with which they are coated, brings a number of economic benefits through more resistant coatings and coatings that can be produced by simplifying manufacturing technology or reducing material consumption in the process. This paper presents the results of a study of dip metallization in zinc baths with Ti additions. Both steel and cast iron substrates were coated and similar results were obtained. The obtained coatings were subjected to SEM analysis with chemical composition studies, TEM characterization with selected area electron diffraction (SAED), and corrosion studies. Particle models of the elementary phases present in the zinc coating made with CaRine 3.0 software were presented and used for phase analysis. It emerged that coatings obtained in zinc baths with the addition of Ti are characterized by a more varied microstructure, the occurrence of phase separations to which Ti segregates, and higher corrosion resistance than classical zinc coatings. The higher corrosion resistance is prompted not only by the Ti content in the intermetallic phases, but also by the observed nanostructure favorably located in the alloy layer. Full article

Determining orientation relationships between different grains or phases via electron diffraction typically requires coincident zone axes, but it is difficult to achieve in most cases due to tilting angle limitations. To address this challenge, a straightforward method for determining the twinning relationship and twin variant in deformed metals is developed by interpreting the selected area electron diffraction (SAED) patterns and corresponding tilt angles in the transmission electron microscope (TEM). The transformation matrix from the sample coordinate system (SCS) to the crystal coordinate system (CCS) is derived to describe the orientation matrix of the observed target. This method is demonstrated by characterizing twins and corresponding Schmid factors in deformed Ti−15Mo alloy even when the zone axes are not coaxial. This method significantly facilitates the determination of multiple orientation relationships and the quantitative analysis of plastic deformation mechanisms in TEM. Full article

Background/Objectives: Gamma irradiation is a promising terminal sterilization method for nanoparticle-based biomedical systems. However, its potential effects on the physicochemical properties and biological performance of multifunctional nanomaterials must be carefully evaluated. This study aimed to assess the structural integrity, sterility, and cytocompatibility of magnetic nanoparticles (MNPs) and bioactive-glass-coated magnetic nanoparticles (MNPBGs), both based on magnetite (Fe₃O₄), after gamma irradiation. Methods: MNPs and MNPBGs were synthesized and subjected to gamma irradiation at 25 kGy, with additional doses explored in preliminary evaluations. Physicochemical characterizations were performed using XRD, TEM, SAED, and Raman spectroscopy. FTIR analyses were conducted on bioactive glass (BG) controls without magnetite. Sterility was evaluated via microbiological assays. Cytocompatibility and nitric oxide (NO) production were assessed using RAW 264.7 macrophages and Saos-2 osteosarcoma cells. Prussian blue staining was used to evaluate cellular uptake. Results: Gamma irradiation preserved the crystal structure, morphology, and size distribution of the nanoparticles. FTIR revealed only minor changes in the silicate network of BG, such as reduced intensity and slight shifting of Si-O-Si and Si-O-NBO bands, indicating limited radiation-induced structural rearrangement without affecting the material’s stability or cytocompatibility. Microbiological assays confirmed complete inhibition of microbial growth. All irradiated samples exhibited high cytocompatibility, with MNPBGs demonstrating enhanced biological responses. Notably, MNPBGs induced a more pronounced NO production in macrophages. Cellular uptake of nanoparticles by Saos-2 cells remained unaffected after irradiation. Conclusions: Gamma irradiation at 25 kGy is an effective sterilization strategy that maintains the structural and functional integrity of MNPs and MNPBGs. These findings support their safe use in sterile biomedical applications, particularly for bone-related therapies involving immunomodulation and drug delivery, with potential relevance for cancer treatment strategies such as osteosarcoma. Full article

Cucumber mosaic virus (CMV) is a destructive viral pathogen of vegetables, fruits, grains, and ornamentals across the globe. This study investigated the comparative antiviral efficacy of chitosan–salicylic acid nanocomposite (Ch/SA NC) and salicylic acid (SA) against CMV in cucumber plants. Transmission electron microscopy (TEM) analyses revealed that Ch/SA NCs can aggregate on the viral coat protein surface, suggesting direct nanoparticle–virus interaction. Greenhouse trials showed that Ch/SA NC, particularly at 90 ppm applied 24 h before CMV inoculation, was the most effective treatment in reducing disease severity and viral load. SA at the same concentration also conferred significant protection when used prophylactically. An RT-PCR analysis confirmed suppression or complete silencing of CMV coat protein gene expression, especially Ch/SA NC-treated plants. Both treatments significantly enhanced the physiological condition of infected plants, including restoration of chlorophyll a, chlorophyll b, and carotenoids, and elevated levels of total phenolics, flavonoids carbohydrates, and proteins. In addition, they boosted the key antioxidant enzymes activities (POX, PPO, SOD) and improved vegetative growth indicators such as plant height, fruit fresh weight, and number of fruits per plant. These results indicate that Ch/SA NC and SA not only inhibit CMV replication but also stimulate host defense responses, improving overall plant health. The strong antiviral effect is likely due to the dual action of Ch/SA NC: direct virus binding and induction of systemic acquired resistance (SAR). Given their efficacy and eco-friendly nature, especially the Ch/SA NC, these treatments offer a promising strategy for integrated viral disease management. Future studies should investigate long-term environmental safety, molecular mechanisms, and field-level applicability. Full article

Blast-induced airblast poses a significant environmental and operational issue for surface mining, affecting safety, regulatory adherence, and the well-being of surrounding communities. Despite advancements in machine learning methods for predicting airblast, present studies neglect essential geomechanical characteristics, specifically rock mass strength (RMS), which is vital for energy transmission and pressure-wave attenuation. This paper presents a capuchin search algorithm-optimized multilayer perceptron (CapSA-MLP) that incorporates RMS, hole depth (HD), maximum charge per delay (MCPD), monitoring distance (D), total explosive mass (TEM), and number of holes (NH). Blast datasets from a granite quarry were utilized to train and test the model in comparison to benchmark approaches, such as particle swarm optimized artificial neural network (PSO-ANN), multivariate regression analysis (MVRA), and the United States Bureau of Mines (USBM) equation. CapSA-MLP outperformed PSO-ANN (RMSE = 1.120, R² = 0.904 compared to RMSE = 1.284, R² = 0.846), whereas MVRA and USBM exhibited lower accuracy. Sensitivity analysis indicated RMS as the main input factor. This study is the first to use CapSA-MLP with RMS for airblast prediction. The findings illustrate the significance of metaheuristic optimization in developing adaptable, generalizable models for various rock types, thereby improving blast design and environmental management in mining activities. Full article

Bacterial leaf blight (BLB), caused by Xanthomonas oryzae pv. oryzae (Xoo), poses a serious threat to rice cultivation. This study presents the green synthesis of zinc oxide nanoparticles (ZnO NPs) using an aqueous leaf extract of the medicinal plant Centella asiatica (L.) Urban and evaluates their potential as dual-function nanopesticides. The synthesized CA-ZnO NPs exhibited high crystallinity, a hexagonal to quasi-spherical morphology, and nanoscale dimensions (~22.5 nm), as confirmed by UV–Vis spectroscopy, XRD, FTIR, SEM, TEM, and SAED analyses. These nanoparticles demonstrated potent antibacterial activity against a highly virulent, field-derived Thai Xoo strain, with a minimum inhibitory concentration (MIC) of 8 µg/mL. Mechanistic investigations revealed substantial membrane disruption, intracellular nanoparticle penetration, and elevated reactive oxygen species (ROS) generation in treated cells. Cytotoxicity testing using human dermal fibroblasts (HDFs) revealed excellent biocompatibility, with no statistically significant reduction in cell viability at concentrations up to 500 µg/mL. In contrast, viability markedly declined at 1000 µg/mL. These findings underscore the selective antibacterial efficacy and minimal mammalian cytotoxicity of CA-ZnO NPs. Overall, CA-ZnO NPs offer a promising green nanopesticide platform that integrates potent antibacterial activity with biocompatibility, supporting future applications in sustainable crop protection and biomedical nanotechnology. Full article

We synthesized QM-AgNPs (Dianthus superbus L.-AgNPs, Qu Mai-AgNPs) by an economical and environmentally friendly method using Dianthus superbus L. extract as a reducing and stabilizing agent. The resulting QM-AgNPs were comprehensively characterized and evaluated for their antioxidant, cytotoxic, and antibacterial activities. Herein, TEM analysis revealed that the QM-AgNPs were predominantly spherical, polydisperse, and exhibited a core particle size ranging from 11 to 18 nm. In contrast, DLS analysis showed a larger hydrodynamic diameter (primarily 60–87 nm), reflecting the hydrated shell and surface biomolecular corona. The crystalline nature of QM-AgNPs was confirmed by XRD and SAED spectra while FTIR spectroscopy indicated the presence of functional groups from the plant extract that may contribute to nanoparticle stabilization. Functional assessments demonstrated that QM-AgNPs exhibited strong antioxidant activity, with efficient DPPH radical scavenging, and selective cytotoxicity against A549 cancer cells while sparing normal cells. Moreover, QM-AgNPs showed significant antibacterial activity against both Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative), likely due to membrane disruption and the leakage of intracellular contents. To explore practical applications, we developed a GEL@AgNPs coating system for the postharvest preservation of grapes. As a result, the reduced weight loss and decay rate suggest a potential role for QM-AgNPs in extending fruit freshness. Comprehensive shelf-life studies are planned to further substantiate the potential of QM-AgNPs as an effective material for active food packaging applications. Full article

This study introduces a novel in situ pulsed current-assisted resistance spot welding method, which differs fundamentally from conventional post-weld heat treatments and is designed to enhance the mechanical performance of 7075-T651 aluminum alloy joints. Immediately after welding, a short-duration pulsed current is applied while the weld remains in a high excess-vacancy state, effectively accelerating precipitation reactions within the weld region. Transmission electron microscopy (TEM) observations reveal that pulsed current treatment promotes the formation of band-like solute clusters, indicating a significant acceleration of the early-stage precipitation process. Interestingly, the formation of quasicrystalline phases—rare in Al-Zn-Mg-Cu alloy systems—is incidentally observed at grain boundaries, exhibiting characteristic fivefold symmetry. Selected area electron diffraction (SAED) patterns further show that these quasicrystals undergo partial dissolution under the influence of the pulsed current, transforming into short-range ordered cluster-like structures. Lap shear tests demonstrate that joints treated with pulsed current exhibit significantly higher peak load and energy absorption compared to untreated specimens. Statistical analysis of weld size confirms that both groups possess comparable weld diameters under identical welding currents, suggesting that the observed mechanical improvements are primarily attributed to microstructural evolution rather than geometric factors. Full article

Gold nanoparticles (AuNPs) were synthesised using ultrasonic spray pyrolysis (USP) with the addition of polyvinylpyrrolidone (PVP) as a stabilising agent and subsequently dried via lyophilisation. The resulting dried AuNPs were redispersed in ethanol and homogenised to ensure uniform dispersion. This AuNP dispersion was then deposited onto a ceramic substrate—aluminum oxide (Al₂O₃)—using plasma jet printing. Comprehensive characterisation of the dispersion, AuNPs, and the resulting printed lines was performed using the following methods: inductively coupled plasma optical emission spectroscopy (ICP-OES), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), scanning transmission electron microscopy (STEM), energy dispersive X-ray spectroscopy (EDS), ultraviolet-visible spectroscopy (UV-Vis), dynamic light scattering (DLS), measurements of dispersion viscosity and printed line roughness. ICP-OES confirmed consistent gold content in the AuNP dispersion, while the SEM and EDS analyses revealed predominantly spherical AuNPs with minimal aggregation and similar size distributions. TEM, SAED, and STEM/EDS confirmed that the crystalline structure and elemental composition of the AuNPs had diverse morphologies and strong gold signals. The UV-Vis, DLS, and zeta potential measurements indicated moderate colloidal stability, and thermogravimetric analysis (TGA) verified the AuNPs dispersion’s composition. The AuNP dispersion exhibited thixotropic behaviour favourable for printing applications, while confocal microscopy confirmed smooth, uniform printed traces, with an average surface line roughness of 1.65 µm. The successful use of plasma printing with the AuNP dispersion highlights its potential for functional material applications in electronics. Full article

This study pioneers the development of a synergistic Ag-doped molecularly imprinted TiO₂ photocatalyst (MIP-Ag-TiO₂) through a multi-strategy engineering approach, integrating molecular imprinting technology with plasmonic metal modification via a precisely optimized sol–gel protocol. Breaking from conventional non-selective photocatalysts, our material features an engineered surface architecture that combines selective molecular recognition sites with enhanced charge separation capabilities, specifically tailored for the targeted degradation of recalcitrant salicylic acid (SA) contaminants. Advanced characterization (XRD, EPR, FT-IR, TEM-EDS) reveals unprecedented structure–activity relationships, demonstrating how template molecule ratios (Ti:SA = 5:1) and calcination parameters (550 °C) collaboratively optimize both adsorption selectivity and quantum efficiency. The optimized MIP-Ag-TiO₂ achieves breakthrough performance metrics: 98.6% SA degradation efficiency at 1% Ag doping, coupled with a record selectivity coefficient R = 7.128. Mechanistic studies employing radical trapping experiments identify a dual •OH/O_2⁻-mediated degradation pathway enabled by the Ag-TiO₂ Schottky junction. This work establishes a paradigm-shifting “capture-and-destroy” photocatalytic system that simultaneously addresses the critical challenges of selectivity and quantum yield limitations in advanced oxidation processes, positioning molecularly imprinted plasmonic photocatalysts as next-generation smart materials for precision water purification. Full article

This study presents the preparation of hybrid iron oxide nanocomposites through a two-step process combining microfluidic-assisted synthesis and post-synthetic surface modification. Fe₃O₄ nanoparticles were synthesized and simultaneously functionalized with salicylic acid using a three-dimensional vortex-type microfluidic chip, enabling rapid and uniform particle formation. The resulting Fe₃O₄/SA nanostructures were further modified with either silver or copper oxide to form iron oxide nanocomposites with enhanced antimicrobial functionality. These nanocomposites were subsequently integrated into silica aerogel matrices using a dip-coating approach to improve surface dispersion, structural stability, and biocompatibility. The structural and morphological properties of the samples were investigated using XRD, FT-IR, TEM with SAED analysis, and Raman microscopy. In vitro cytotoxicity and antimicrobial assays demonstrated that Fe₃O₄/SA–Ag and Fe₃O₄/SA–CuO exhibit potent antibacterial activity and cell type-dependent biocompatibility. In vivo biodistribution studies showed no accumulation in major organs and selective clearance via the spleen, validating the systemic safety of the platform. These findings highlight the potential of the synthesized nanocomposites as biocompatible, antimicrobial coatings for advanced biomedical surfaces. Full article

The recurrence of bone cancer poses severe complications, particularly after orthopedic surgery, necessitating advanced biomaterials with dual functionality. This study develops nanostructured coatings composed of hydroxyapatite, carboplatin, and quercetin, designed to enhance bone regeneration while delivering localized cancer therapy. These coatings present a promising solution for hip endoprostheses, addressing osteointegration and tumor recurrence prevention simultaneously. Hydroxyapatite was synthesized and characterized using XRD, TEM, SAED, FTIR, and SEM to assess crystallinity, surface morphology, and functional groups. The coatings were obtained by MAPLE. In vitro biocompatibility tests showed that HAp@CPT and HAp@CPT/QUE coatings supported osteoblast viability and adhesion while exhibiting selective cytotoxic effects on osteosarcoma cells. The Griess assay indicated that nitric oxide (NO) levels remained unchanged in hFOB osteoblasts, confirming that neither coating induced inflammatory responses in healthy cells. In contrast, MG63 osteosarcoma cells exhibited significantly elevated NO levels (p < 0.05) in response to HAp@CPT/QUE, suggesting increased oxidative stress. MTT assay results showed a 12% and 28% reduction in osteosarcoma cell viability for HAp@CPT and HAp@CPT/QUE, respectively. Phase-contrast microscopy further confirmed strong osteoblast adhesion and reduced osteosarcoma attachment, particularly on HAp@CPT/QUE surfaces. These findings highlight the dual functionality of hydroxyapatite–carboplatin–quercetin coatings, promoting osteointegration while exerting localized anticancer effects. Their bone-regenerative and selective cytotoxic properties make them a promising material for hip endoprostheses in oncological orthopedic applications. Full article

This study presents an easy and rapid two-step electrodeposition method for the synthesis of a novel hierarchical dendritic AuPt bimetallic nanocomposite electrode. Ascorbic acid served as both a reducing and directing agent, while a roughened carbon substrate facilitated the formation of the unique dendritic nanostructure. The structural and compositional properties of the synthesized material were comprehensively characterized using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), selected area electron diffraction (SAED), and transmission electron microscopy (TEM). The resulting nanocomposite exhibited a significantly enhanced specific surface area of 6.97 m² g⁻¹, compared to commercial Pt/C. Electrochemical investigations demonstrated superior electrocatalytic activity and durability for methanol oxidation in the prepared AuPt nanocomposite electrode, suggesting its promising potential for fuel cell applications. Full article

In this study, Fe₃O₄@SiO₂@TiO₂ (FS-FT (0 g)) photocatalysts, featuring a magnetic core–shell structure, and Fe-doped Fe₃O₄@SiO₂@Fe-TiO₂ (FS-FT (x g)) photocatalysts, were fabricated via the sol–gel method. Structural and compositional analyses of the processed samples were systematically conducted through X-ray diffraction (XRD), transmission electron microscopy (TEM) with selected area electron diffraction (SAED), surface-sensitive X-ray photoelectron spectroscopy (XPS), and optical property assessment via UV-Vis diffuse reflectance spectroscopy (UV-DRS). The results show that TiO₂ on the outer layer of FS-FT (0 g) and FS-FT (x g) has an anatase structure, and that Fe is doped into FS-FT (x g). The photodegradation of methyl orange (MO) using FS-FT (0 g) and FS-FT (x g) with various Fe doping levels was evaluated in both pure MO (C₀ = 10 mg/L) and MO-Na₂SO₄-blended solutions. Under irradiation with high-pressure mercury lamps, the removal rates of MO using FS-FT (0 g) and FS-FT (0.36 g) in pure MO solution reached 90.25% and 99% at 25 min, respectively, which indicates that FS-FT (0.36 g) can enhance photocatalytic performance. The removal rates of MO using FS-FT (0 g) and FS-FT (0.36 g) in MO-Na₂SO₄-blended solution (C₀ = 10 mg/L, C_Na2SO4 = 12.5 g/L) reached 92.38% and 97.16% at 25 min, respectively. The removal rate of MO using FS-FT (0.36 g) decreased in MO-Na₂SO₄-blended solution in the previous 25 min, which indicates that Na₂SO₄ can inhibit degradation using FS-FT (0.36 g). The degradation experiments of MO-Na₂SO₄-blended solutions with different concentrations of Na₂SO₄ using FS-FT (0.36 g) showed that as the concentration of Na₂SO₄ increases, the inhibitory effect becomes more pronounced. Recovery and recycling experiments confirmed that the photocatalyst exhibited robust degradation performance over multiple cycles. Kinetic analysis of the photocatalytic data, based on a first-order model, was conducted to explore the underlying degradation principles. Full article

This study investigates silver (Ag), copper oxide (CuO), and bimetallic Ag/CuO nanoparticles (NPs) synthesized using Cistus creticus L. extract, focusing on their synthesis, physicochemical characteristics, and antioxidant activity. Green synthesis methods utilizing plant extracts offer environmentally benign routes for nanoparticle fabrication, attracting significant interest across multiple fields. NP formation was confirmed by UV/Vis and total X-ray fluorescence (TXRF) spectroscopy, while dynamic and electrophoretic light scattering (DLS, ELS) characterized particle size and ζ-potential, respectively. AgNPs exhibited the smallest particle size (30.8 ± 8.81 nm), while CuONPs had the largest (44.07 ± 19.19 nm). For Ag/CuONPs, the ζ-potential value was −77.9 ± 2.99 mV. Morphological and structural analyses performed using transmission electron microscopy (TEM), selected area electron diffraction (SAED), and X-ray diffraction (XRD) revealed that AgNPs were spherical, while CuONPs and Ag/CuONPs exhibited spherical and polymorphic structures. Colloidal stability studies over 60 days demonstrated that the NPs were highly stable, indicating their suitability for pharmaceutical and cosmetic applications. Antioxidant activity, assessed via the DPPH assay, demonstrated that CuONPs had the highest free radical scavenging activity. By systemically comparing Ag, CuO, and bimetallic Ag/CuONPs synthesized from Cistus creticus L. extract, this study provides valuable insights for the development of tailored nanomaterials with diverse applications in pharmaceutics and cosmetics. Full article