Search Results (200)

Among the new strategies for managing diseases in agricultural crops is the application of metallic nanoparticles due to their ability to inhibit the development of phytopathogenic microorganisms and to induce plant defense responses. Therefore, this research evaluated the effects of silver (AgNPs), zinc oxide (ZnONPs), and silicon dioxide (SiO₂NPs) nanoparticles on symptom progression and physiological parameters in two pathosystems: Pseudomonas syringae pv. tomato (Psto) in tomato (pathosystem one, culturable pathogen) and Candidatus Liberibacter solanacearum (CaLso) in pepper plants (pathosystem two, non-culturable pathogen). For in vitro pathosystem one assays, SiO₂NPs did not inhibit Psto growth. The minimum inhibitory concentration (MIC) was 31.67 ppm for AgNPs and 194.3 ppm for ZnONPs. Furthermore, the minimum lethal concentration (MLC) for AgNPs was 100 ppm, while for ZnONPs, it was 1000 ppm. For in planta assays, ZnONPs, AgNPs, and SiO₂NPs reduced the number of lesions per leaf, but only ZnONPs significantly decreased the severity. Regarding pathosystem two, AgNPs, ZnONPs, and SiO₂NPs application delayed symptom progression. However, only AgNPs significantly reduced severity percentage. Moreover, treatments with AgNPs and SiO₂NPs increased the plant height and dry weight compared to the results for the control. Full article

Difficult, extreme operating conditions of parabolic antennas under precipitation and sub-zero temperatures require the creation of effective heating systems. The purpose of the research is to develop a multilayer coating containing two metal-ceramic layers, epoxy composite layers, carbon fabric, and an outer layer of basalt fabric, which allows for effective heating of the antenna, and to study the properties of this coating. The multilayer coating was formed on an aluminum base that was subjected to abrasive jet processing. The first and second metal-ceramic layers, Al₂O₃ + 5% Al, which were applied by high-speed multi-chamber cumulative detonation spraying (CDS), respectively, provide maximum adhesion strength to the aluminum base and high adhesion strength to the third layer of the epoxy composite containing Al₂O₃. On this not-yet-polymerized layer of epoxy composite containing Al₂O₃, a layer of carbon fabric (impregnated with epoxy resin) was formed, which serves as a resistive heating element. On top of this carbon fabric, a layer of epoxy composite containing Cr₂O₃ and SiO₂ was applied. Next, basalt fabric was applied to this still-not-yet-polymerized layer. Then, the resulting layered coating was compacted and dried. To study this multilayer coating, X-ray analysis, light and raster scanning microscopy, and transmission electron microscopy were used. The thickness of the coating layers and microhardness were measured on transverse microsections. The adhesion strength of the metal-ceramic coating layers to the aluminum base was determined by both bending testing and peeling using the adhesive method. It was established that CDS provides the formation of metal-ceramic layers with a maximum fraction of lamellae and a microhardness of 7900–10,520 MPa. In these metal-ceramic layers, a dispersed subgrain structure, a uniform distribution of nanoparticles, and a gradient-free level of dislocation density are observed. Such a structure prevents the formation of local concentrators of internal stresses, thereby increasing the level of dispersion and substructural strengthening of the metal-ceramic layers’ material. The formation of materials with a nanostructure increases their strength and crack resistance. The effectiveness of using aluminum, chromium, and silicon oxides as nanofillers in epoxy composite layers was demonstrated. The presence of structures near the surface of these nanofillers, which differ from the properties of the epoxy matrix in the coating, was established. Such zones, specifically the outer surface layers (OSL), significantly affect the properties of the epoxy composite. The results of industrial tests showed the high performance of the multilayer coating during antenna heating. Full article

Background/Objectives: Silicon dioxide nanoparticles (SiO₂NPs) do not exist in isolation in the environment but can interact with other substances, thus influencing their toxic effects on aquatic organisms. We assessed the combined impact of SiO₂NPs and N-acetylcysteine (NAC), an antioxidant with the potential to counteract nanoparticle-induced oxidative stress (OS). Methods: Behavioral assessments, including the social interaction test and color preference test, were performed to evaluate neurobehavioral changes. OS biomarkers, including malondialdehyde (MDA) levels for lipid peroxidation and the activity of key antioxidant enzymes such as glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD), were assessed to evaluate the extent of cellular damage. Results: The results indicate that prolonged exposure to SiO₂NPs induces significant behavioral disruptions, including reduced exploratory behavior and increased anxiety-like responses. Furthermore, biochemical analysis revealed increased OS, suggesting nanoparticle-induced cellular toxicity. NAC co-treatment partially reversed these effects, particularly improving locomotor outcomes and antioxidant response, but was less effective on social behavior. Conclusions: These findings highlight the ecological and health risks posed by SiO₂NPs and point toward the need for further toxicological studies on their long-term biological effects. Full article

There is considerable interest in broadband nanomaterials, particularly transparent semiconductor oxides, within both fundamental research and technological applications. Historically, it has been considered that the variation in dopant concentration during the synthesis of semiconductor materials is a crucial factor in activating and/or modulating the optical and structural properties, particularly the bandgap and the parameters of the unit cell, of semiconductor oxides. Recently, tin oxide has emerged as a key material due to its excellent structural properties, optical transparency, and various promising applications in optoelectronics. This study utilized the ultrasonic spray pyrolysis technique to synthesize aluminum-doped tin oxide (ATO) thin films on quartz and polished single-crystal silicon substrates. The impact of varying aluminum doping levels (0, 2, 5, and 10 at. %) on morphology and structural and optical properties was examined. The ATO thin films were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmittance spectroscopy. SEM images demonstrated a slight reduction in the size of ATO nanoparticles as the aluminum doping concentration increased. XRD analysis revealed a tetragonal crystalline structure with the space group P42/mnm, and a shift in the XRD peaks to higher angles was noted with increasing aluminum content, indicating a decrease in the crystalline lattice parameters of ATO. The transmittance of the ATO films varied between 75% and 85%. By employing the transmittance spectra and the established Tauc formula the optical bandgap values of ATO films were calculated, showing an increase in the bandgap with higher doping levels. These findings were thoroughly analyzed and discussed; additionally, an effort was made to clarify the contradictory analyses present in the literature and to identify a doping range that avoids the onset of a secondary phase. Full article

Drought stress is one of the main factors limiting seed germination and seedling establishment in field crops such as jalapeño peppers (Capsicum annuum L.). Nanopriming, a seed improvement technique using nanoparticle suspensions, has emerged as a sustainable approach to improving water use efficiency during the early stages of development. This study evaluated the effects of zinc oxide (ZnO, 100 mg·L⁻¹), silicon dioxide (SiO₂, 10 mg·L⁻¹), and their combination (ZnO + SiO₂), stabilized with chitosan, on the germination yield and drought tolerance of jalapeño seeds under mannitol-induced water stress (0%, 15%, and 30%). Compared to the hydroprimed control (T1), nanoparticle treatments consistently improved seed yield. Priming with ZnO (T2) increased the germination percentage by up to 25%, priming with SiO₂ (T3) improved the germination rate by 34%, and the combined treatment (T4: ZnO + SiO₂) improved the fresh weight of the seedlings by 40%. Proline accumulation increased 7.5 times, antioxidant capacity (DPPH) increased 6.5 times, and total phenol content increased 4.8 times in the combined treatment. Flavonoid levels also showed notable increases, suggesting enhanced antioxidant defense. These results clearly demonstrate the superior efficacy of nanoparticle pretreatment compared to conventional hydraulic pretreatment, especially under drought conditions. Multivariate analysis further highlighted the synergistic role of ZnO and SiO₂ in improving osmolite accumulation, antioxidant activity, and water use efficiency. Nanopriming with ZnO and SiO₂ offers a promising, economical, and scalable strategy to improve germination, early growth, and drought resistance in jalapeño pepper cultivation under semi-arid conditions. Full article

The importance and challenges of ethylene detection based on combustion-type low-cost commercial sensors for agricultural and industrial applications are well-established. This work summarizes the significant progress in ethylene detection based on an innovative Gas Metal Oxide Semiconductor (GMOS) sensor and a new catalytic composition of metallic nanoparticles. The paper presents a study on ethylene and ethanol sensing using a miniature catalytic sensor fabricated by Complementary Metal Oxide Semiconductor–Silicon-on-Insulator–Micro-Electro-Mechanical System (CMOS-SOI-MEMS) technology. The GMOS performance with bimetallic palladium–platinum (Pd-Pt) and monometallic palladium (Pd) and platinum (Pt) catalysts is compared. The synergetic effect of the Pd-Pt catalyst is observed, which is expressed in the shift of combustion reaction ignition to lower catalyst temperatures as well as increased sensitivity compared to monometallic components. The optimal catalysts and their temperature regimes for low and high ethylene concentrations are chosen, resulting in lower power consumption by the sensor. Full article

Silicon nanoparticles (SiNPs) have emerged as multifunctional tools in sustainable agriculture, demonstrating significant efficacy in promoting crop growth and enhancing plant resilience against diverse biotic and abiotic stresses. Although their ability to strengthen antioxidant defense systems and activate systemic immune responses is well documented, the fundamental mechanisms driving these benefits remain unclear. This review synthesizes emerging evidence to propose an innovative paradigm: SiNPs remodel plant redox signaling networks and stress adaptation mechanisms by forming protein coronas through apoplastic protein adsorption. We hypothesize that extracellular SiNPs may elevate apoplastic reactive oxygen species (ROS) levels by adsorbing and inhibiting antioxidant enzymes, thereby enhancing intracellular redox buffering capacity and activating salicylic acid (SA)-dependent defense pathways. Conversely, smaller SiNPs infiltrating symplastic compartments risk oxidative damage due to direct suppression of cytoplasmic antioxidant systems. Additionally, SiNPs may indirectly influence heavy metal transporter activity through redox state regulation and broadly modulate plant physiological functions via transcription factor regulatory networks. Critical knowledge gaps persist regarding the dynamic composition of protein coronas under varying environmental conditions and their transgenerational impacts. By integrating existing mechanisms of SiNPs, this review provides insights and potential strategies for developing novel agrochemicals and stress-resistant crops. Full article

The integration of Silicon Carbide (SiC) nanoparticles into Laser Powder Bed Fusion (LB-PBF) Molybdenum (Mo) printing represents a significant advancement in refractory metal additive manufacturing. Our investigation examined how varying SiC nanoparticle sizes affect the microstructural and electrical properties of LB-PBF-printed molybdenum components while maintaining a 0.01 mass fraction of Mo. At an Linear Energy Densities (LED) of 1.8 J/mm, the addition of 80 nm SiC particles achieved a 46% reduction in porosity, while sheet resistance decreased by 6% at LED of 2.0 J/mm with 80 nm SiC particles. These performance improvements stem from several mechanisms: SiC particles serve as oxygen scavengers, facilitate secondary phase formation, and enhance laser absorption efficiency. Their dual role as sacrificial oxidizing agents and Mo disilicide phase promoters represents a novel approach to addressing microcracking and porosity in LB-PBF-printed Mo components. Through systematic investigation of particle size effects on both microscale and nanoscale properties, our findings suggest that optimized nanoparticle addition could become a universal strategy for enhancing LB-PBF processing of refractory metals, particularly in applications requiring enhanced mechanical and electrical performance. Full article

Tall fescue (Festuca arundinacea Schreb.) is a herbaceous species that is commonly used for ecological slope restoration in China. However, water scarcity often constrains its growth due to the unique site conditions of steep slopes and climate-induced drought stress. This study aims to compare the ameliorative effects of silicon nanoparticles (Si NPs) and cellulose nanocrystals (CNCs) on drought stress in tall fescue and to elucidate their underlying mechanisms of action. The results indicated that drought stress impaired photosynthesis, restricted nutrient absorption, and increased oxidative stress, ultimately reducing biomass. However, Si NPs and CNCs enhanced drought tolerance and promoted biomass accumulation by improving photosynthesis, osmotic regulation, and antioxidant defense mechanisms. Specifically, Si NP treatment increased biomass by 48.71% compared to drought-stressed control plants, while CNCs resulted in a 33.41% increase. Transcriptome sequencing further revealed that both nanomaterials enhanced drought tolerance by upregulating genes associated with photosynthesis and antioxidant defense. Additionally, Si NPs improved drought tolerance by stimulating root growth, enhancing nutrient uptake, and improving leaf structure. In contrast, CNCs play a distinct role by regulating the expression of genes related to cell wall synthesis and metabolism. These findings highlight the crucial roles of these two nanomaterials in plant stress protection and offer a sustainable strategy for the maintenance and management of slope vegetation. Full article

Tungsten disulfide (WS₂) is attractive for the development of chemiresistive sensors due to its favorable band gap, as well as its mechanical strength and chemical stability. In this work, we elaborate a procedure for the synthesis of thin films consisting of vertically and/or horizontally oriented WS₂ nanoparticles by sulfurizing nanometer-thick tungsten layers deposited on oxidized silicon substrates using magnetron sputtering. According to X-ray photoelectron spectroscopy and Raman scattering data, WS₂ films grown in an H₂-containing atmosphere at 1000 °C are almost free of tungsten oxide. The WS₂ film’s thickness is controlled by varying the tungsten sputtering duration from 10 to 90 s. The highest response to nitrogen dioxide (NO₂) at room temperature was demonstrated by the film obtained using a tungsten layer sputtered for 30 s. The increased sensitivity is attributed to the high surface-to-volume ratio provided by the horizontal and vertical orientation of the small WS₂ nanoparticles. Based on density functional calculations, we conclude that the small in-plane size of WS₂ provides many high-energy sites for NO₂ adsorption, which leads to greater charge transfer in the sensor. The detection limit of NO₂ calculated for the best sensor (WS₂-30s) is 15 ppb at room temperature and 8 ppb at 125 °C. The sensor can operate in a humid environment and is significantly less sensitive to NH₃ and a mixture of H₂, CO, and CO₂ gases. Full article

A Pd-decorated V₂O₅/porous silicon (Pd-V₂O₅/PSi) composite was synthesized via magnetron sputtering for enhanced NO₂ gas sensing. The material’s morphology and composition were systematically characterized, and its gas sensing performance was evaluated through comprehensive experimental measurements and first-principles calculations. The decoration of Pd nanoparticles significantly improved the sensing capabilities of the V₂O₅/PSi composite, particularly enhancing sensitivity and response/recovery characteristics. Experimental results revealed a 3.1-fold increase in response to specific NO₂ concentrations (ppm level) compared to the undecorated V₂O₅/PSi sensor. The composite exhibited rapid NO₂ response at room temperature with excellent selectivity, reproducibility, and long-term stability. First-principles calculations elucidated the structural, electronic, and adsorption properties of the Pd-V₂O₅/PSi composite, uncovering the gas sensing mechanism in NO₂ environments. This combined experimental and theoretical study provides valuable insights for developing advanced gas sensors and lays a foundation for optimizing metal oxide-based sensing materials. Full article

The development and analysis of the properties of a new material based on UV-curable acrylate monomers with silicon-containing hydroxyapatite and zinc oxide nanoparticles as an antibacterial component and gelatin was carried out. Using this material in orthopedics and dentistry is very convenient because it covers any surface geometry of metal implants and hardens under ultraviolet light. In this work, sorption properties, changes in porosity, and mechanical properties of the material were investigated. The conditions for obtaining hydroxyapatite (HA) nanoparticles and the presence of silicon oxide nanoparticles and organic for the shell in an aqueous medium were studied for the pH of the medium, the sequence of administration and concentration of the material components, as well as antibacterial properties. This polymer material is partially resorbable. That supports not only the growth of bone cells but also serves as a protective layer. It reduces friction between organic tissues and a metal implant and can be a solution to the problem of the aseptic instability of metal implants. The material can also be used to repair damaged bones and cartilage tissues, especially in cases where the application and curing procedure is performed using laparoscopic methods. In this work, the authors propose a simple and quite cheap method for obtaining material based on photopolymerizable acrylates and natural gelatin with nanoparticles of HA, zinc oxide, and silicon oxide. The method allows one to obtain a composite material with different nanoparticles in a polymer matrix which retain the requisite properties needed such as active-sized HA, antibacterial ZnO, and structure-forming and stability-improving SiO2 nanoparticles. Full article

Research into the introduction of alloying and reinforcing nanocomposites into nickel (Ni) coatings has been motivated by the need for tribologically superior coatings that will improve energy efficiency. Using pulse electrodeposition, this work investigates the effects of adding cobalt (Co) as the alloying nanoparticle and silicon carbide (SiC), zirconium oxide (ZrO₂), and aluminium oxide (Al₂O₃) as reinforcing nanocomposites to Ni coatings. The surface properties, mechanical strength, nanotribological behaviour, and wettability of these coatings were analysed. Surface characteristics were evaluated by the use of a Scanning Electron Microscope, revealing a grain dimension reduction of approximately ~7–43% compared to pristine Ni coatings. When alloying and reinforcing nanocomposites were added to Ni coatings, nanoindentation research showed that there was an increase in nanohardness of ~12% to ~69%. This resulted in an improvement in the tribological performance from approximately 2% to 65%.The hydrophilic nature of Ni coatings was observed with wettability analysis. This study demonstrates that nanocomposite reinforcement can be used to customise Ni coatings for applications that require exceptional tribological performance. The results point to the use of Ni-Co coatings for electronics and aerospace sectors, with more improvements possible with the addition of reinforcing nanoparticles. Full article

Nanoparticles exhibit diverse effects when added as additives to oily medium, enhancing tribological properties and surface characteristics. Studies have shown that many oxide ceramic nanoparticles improve friction and wear, while mixtures also demonstrate favorable tribological properties. This study explores the tribological effect of an yttria–silica (Y₂O₃, SiO₂) nanoparticle mixture in a Group III base oil medium. The results reveal that the yttria–silica mixture significantly reduces friction (−8–17%), mean wear scar diameter (−32%), and wear volume (−94%), while increasing load-bearing capacity (+114%) by creating a durable boundary layer. Observations from scanning electron microscopy revealed the original surface is protected. EDX analyses highlight the boundary layer’s elemental composition, which is high in yttrium, silicon, and oxygen and found in higher areas. XRD analysis could not detect the yttria nanoparticle additive within the boundary layer, suggesting that it fragmented due to sliding stress, resulting in an amorphous structure for the new boundary layer. TEM imaging confirmed that the boundary layer thickness is 40–45 nm. These findings demonstrate significant potential for industrial applications in developing advanced, high-performance lubricants for demanding mechanical systems. Full article

Copper oxide nanoparticles (CuONPs) offer promising antimicrobial properties against a range of pathogens, addressing the urgent issue of antibiotic resistance. This study details the synthesis of glutamic acid-coated CuONPs (GA-CuONPs) and their functionalisation on medical-grade silicone tubing, using an oxysilane bonding agent. The resulting coating shows significant antimicrobial activity against both Gram-positive and Gram-negative bacteria, including multidrug-resistant strains, while remaining non-toxic to human cells and exhibiting stable adherence, without leaching. This versatile coating method can be applied during manufacturing, or for ad hoc modifications, enhancing the antimicrobial properties of medical devices. Full article