Search Results (77)

The present work aimed at resolving the mystery accompanying the famous Ko-Kutani Honzenji temple shallow bowl by investigating the main elements associated with the coating composition in the surface decoration. This unique vessel belongs to Honzenji temple, located in the Maeda Domain (today’s Ishikawa Prefecture) and is on display at the Ishikawa Prefecture Kutaniyaki Art Museum in Kaga. The Honzenji temple bowl bears a cryptic figure painted in red enamel on the underside and story has it that the Maeda Lord himself may have painted it in the mid-17th century, thus making the bowl a very relevant piece of the history of the Maeda clan, Ishikawa Prefecture (Maeda fiefdom in the Edo period), and Japanese porcelain as a whole. Yet the identification of the actual firing date of the bowl has proven a daunting task for curators worldwide. On the basis of the previously published studies on the world’s most extensive collection of Ko-Kutani Masterpieces belonging to the Ishikawa Prefectural Museum of Art, and shards excavated at Kaga kiln sites, including the celebrated Hakuji bowl (Ishikawa Archaeological Foundation), both conducted by Energy-Dispersive X-Ray Fluorescence spectroscopy (pED-XRF), and in consideration of the absolute prohibition to sample or even touch the Honzenji bowl, pED-XRF was once again selected as the most suitable technique for the analysis of all the enamels and glazing materials. Analytical evidence, for the first time ever, has proven crucial to resolving the issue by enabling the precise dating of the bowl and unveiling the true story behind its technical features and the cryptic underside decoration. Full article

The windings of aerospace motors are fabricated using enameled wires; with polyimide (PI) serving as the primary material for their insulating enamel coatings, thermal aging is the predominant factor contributing to insulation failure in enameled wires. The prolonged natural aging process of enameled wires, coupled with the complexity and sluggish variation rates of dielectric parameters used for aging monitoring, presents significant challenges in developing a universal method for assessing insulation performance. To address this challenge, our study determined accelerated aging conditions based on the Arrhenius law, fabricated twisted-pair specimens, and implemented a step-stress aging protocol, in order to monitor the insulation capacitance (IC) and dielectric dissipation factor (tan δ) of the sample. Finally, a two-parameter Weibull distribution plot was established to characterize the relationship between service life and failure probability. Initial-value normalization combined with B-spline interpolation was employed to construct IC–life correlation curves. A novel method for monitoring PI-enameled wire insulation life using IC variation rate was proposed and experimentally validated, providing a methodological framework for lifespan prediction of aerospace motor windings. Finally, a two-parameter Weibull distribution plot was established to characterize the relationship between service life and failure probability. Initial-value normalization combined with B-spline interpolation was employed to construct IC–life correlation curves. The rationality of the method using IC change rate to monitor the insulation lifetime of polyimide-enameled wire was verified, the lifetime assessment of aviation motor stator windings was achieved by monitoring corresponding dielectric parameters, and a reference standard for the maintenance and support of aviation equipment was provided. Full article

The development of hybrid organic coatings for corrosion protection remains a key research priority. This study focuses on synthesising Layered Double Hydroxide (ZnGa-LDHs) intercalated with environmentally friendly disodium sebacate (SB) corrosion inhibitor, forming ZnGa-SB. To overcome the challenge of limited dispersibility in organic coatings, ZnGa-SB was combined with Graphene Nanoribbons (GNR), produced through the oxidative unzipping of multi-walled carbon nanotubes (MWCNT). The resulting composite, ZnGa-SB/GNR, was synthesised using an in situ hydrothermal method and incorporated into polyurethane (PU) enamel. The synergy between high-barrier GNRs and active ZnGa-SB creates a “labyrinth effect” that effectively inhibits the diffusion of corrosive species. Microstructural analysis, including XRD, FT-IR, Raman, TGA, FE-SEM, and EDS, confirmed the nanofiller structure. The nanofillers were embedded into acrylic resin (AC) for short-term anticorrosive testing in a 0.1 M NaCl solution and then into PU for long-term evaluation in a 3.5 wt% NaCl solution, using electrochemical impedance spectroscopy (EIS). The PU/ZnGa-SB/GNR coating exhibited a high impedance modulus of 5.90 × 10⁷ Ω cm² at |Z|_0.01 Hz, even after 2688 hours of immersion, indicating enhanced corrosion resistance. This coating demonstrated superior performance in cross-cut and pencil hardness tests and sustained less damage in salt spray analysis compared to other coatings. The synergistic effect offers a promising approach for developing next-generation hybrid anti-corrosive coatings. Full article

The study aims to reconstruct the life history of an individual whose skeleton was recovered during the excavation of the late medieval Pauline monastery of the Blessed Virgin Mary on Moslavina Mountain, Croatia. The monastery was one of the most important ecclesiastical centres in continental Croatia during the 14th/15th centuries CE and was abandoned between 1520 and 1544 due to fear of imminent Ottoman attacks. The inscription and coat of arms on the tombstone of a tomb located in the chancel, next to the main altar, indicate that the skeleton belongs to Sofia Kaštelančić née di Prata (di Pordenone), a member of Croatian late medieval high-ranking nobility. We conducted a conventional bioarchaeological study, carbon and nitrogen stable isotopes analysis, paleoradiological imaging (CT/CBCT scanning), and three-dimensional facial reconstruction. The skeleton belongs to a middle-aged woman between 40 and 50 years old with an estimated stature of about 161 cm. Numerous pathological changes, such as ante mortem tooth loss, caries, abscess, linear enamel hypoplasia, dysodontiasis, and osteophytosis were observed, with the most notable pathology being the fracture of the right ankle, a fact also confirmed by CT scanning. Carbon and nitrogen isotopic values are consistent with a terrestrial diet based on C₃ plants with no marine input, and the consumption of large quantities of animal-based proteins. Three-dimensional facial reconstruction made it possible for the first time in over 500 years to obtain the approximate physical appearance of the individual. The presented results are consistent with the hypothesis that the skeleton probably belongs to Sofia Kaštelančić. Nevertheless, none of the observed osteological traits are individually or collectively diagnostic of Sofia, so, in the absence of individualising evidence, the identification remains hypothetical rather than demonstrative. Full article

This study develops a comprehensive decision-making approach to sustainable product selection for chemical industry supply chains under uncertainty. Five product categories -enamel, ceramics, pigments, non-stick coatings, and glass- were evaluated through fifteen criteria along environmental, economic, and social sustainability dimensions. The hybrid methodology combines Fuzzy SWARA, which weights criteria based on expert opinion, with Fuzzy ARAS, which ranks the alternatives accordingly. The study found that occupational health and safety, consumer safety and health, and water usage are the most important criteria, reflecting a human-centered approach to sustainability decision-making. Ceramics had the best performance score, followed by enamel and non-stick coating. Sensitivity analysis confirmed the robustness of these rankings across various weighting scenarios. The findings indicate that decision-makers in the chemical industry prioritize worker and consumer protection alongside environmental resource stewardship. This framework provides practitioners with a structured method for integrating sustainability considerations into supply chain product portfolio decisions, balancing environmental impact, economic performance, and social responsibility. Full article

Background/Objectives: The aim of this study was to evaluate the effects of sodium trimetaphosphate (TMP) and fluoride (F) on the surface free energy (SFE) of enamel coated with human salivary pellicle in vitro, both after treatment with the gels and after an erosive challenge. Methods: Bovine enamel discs (n = 10/group) were randomly allocated into seven treatment groups (gels): placebo (without any actives), low-fluoride gels (4500 ppm F—“4500F”) supplemented or not with microparticulate TMP (5%) or nanoparticulate (2.5% or 5%) TMP, 9000 ppm F (positive control), and 12,300 ppm F (acid gel, commercial control); a negative control group (i.e., untreated enamel) was included. Discs were exposed to human saliva (2 h), treated with the gels (1 min) and subjected to a 1-min acid challenge. Three probing liquids were used to assess enamel SFE. Data were submitted to two-way, repeated-measures ANOVA followed by Tukey’s test, and by Mann–Whitney’s test (p < 0.05). Results: SFE was significantly altered after exposure to saliva, changing from hydrophobic to slightly hydrophilic; gel treatment further increased enamel hydrophilicity (i.e., electron-donor properties), without significant differences among gels. After the erosive challenge, the enamel surface became significantly less hydrophilic for all groups; the highest values were observed for both gels containing nanoparticulate TMP. As for the overall SFE, the best performance was achieved by the gel containing 5% nanometric TMP. Conclusions: SFE of salivary-coated enamel was significantly influenced by the treatment gels, which promoted increases in hydrophilicity. Gels containing TMP, especially at nanoscale, promoted higher resistance to changes in hydrophilicity after an erosive challenge. Full article

Background: Substituted hydroxyapatites (HAps) are widely used in oral-care formulations for enamel repair; however, head-to-head comparisons among commercial grades remain limited. Objective: To compare four commercial HAps: A (Kal-HAp), B (FL-HAp), C (FL-HAp-SC), and D (microRepair^®, a biomimetic Zn–carbonate-substituted HAp) and to evaluate their ability to form an enamel-like coating in vitro. Methods: We characterized the powders by X-ray diffraction (crystalline phase, Landi crystallinity index), FTIR-ATR (phosphate/carbonate bands), SEM/EDS (morphology, surface Ca/P), and DLS (particles size, ζ-potential). In vitro, human enamel sections were treated with 5% slurries in artificial saliva; surface coverage was quantified by image analysis on SEM. Results: All commercial materials analyzed in this work were composed of HAp. Differences were observed between HApin terms of crystallinity-range [2 Theta 8.0–60.0°], carbonate substitution (ATR [carbonate group evaluated −870 cm⁻¹]), and particle size (DLS [in a range 0.1–10,000 nm], Z-mean [mV]). On enamel, all samples form a hydroxyapatite layer; coverage differed between groups ([A] 28.83 ± 7.35% vs. [B] 31.11 ± 3.12% vs. [C] 57.20 ± 33.12% vs. [D] 99.90 ± 0.12%), with the biomimetic Zn–carbonate-substituted HAp showing the highest coverage, and the post-treatment Ca/P ratio approached values similar to those of dental enamel. Conclusions: Complementary physic-chemical signatures (crystallinity, carbonate substitution, and morphology) relate to enamel-surface coverage in vitro, providing evidence base for selecting HAp grades for enamel-repair formulations, which is a practical implication for product design. Full article

Zirconia’s superior mechanical properties and biocompatibility have made it a cornerstone of modern prosthodontics, yet achieving durable biomimetic bonding to tooth structure remains a challenge. This scoping review synthesizes evidence on bonding strategies for zirconia-based fixed dental prostheses (FDPs), evaluating surface treatments, cementation protocols, and long-term performance. Following PRISMA-ScR guidelines, 18 studies from PubMed, Scopus, Web of Science, and Embase were thoroughly analyzed. Key findings indicate that tribochemical silica coating (e.g., Rocatec™) combined with 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-based primers (e.g., Panavia V5) is associated with the highest bond strengths (>40 MPa) and exceptional clinical survival rates (e.g., >95% at 15 years for resin-bonded FDPs). These combined mechanical–chemical strategies can be viewed as an attempt to create a biomimetic, hybrid interface akin to the natural enamel–dentin junction. Additively manufactured zirconia exhibits inferior bonding compared to milled counterparts, while ethyl cellulose coatings applied to the bonding surface effectively prevent contamination from saliva and moisture during intraoral try-in procedures. However, heterogeneous testing protocols and limited long-term clinical data highlight the need for standardized aging models and randomized trials. This review consolidates current evidence, offering clinically actionable recommendations through a biomimetic lens while identifying critical gaps for future research. Full article

Although approximately half of global lithium consumption is used in the rechargeable battery industry, lithium is also in demand for other specialized applications, such as high-temperature lubricants, ceramics, glass, and pharmaceuticals. The growing need for efficient lithium recovery and recycling underscores the importance of fast and accurate analytical tools for determining lithium concentrations in non-compliant and waste materials generated by industrial processes. In this paper, we present a machine learning-based procedure utilizing Laser-Induced Breakdown Spectroscopy (LIBS) to accurately quantify lithium concentrations in lithium-rich non-compliant materials derived from the industrial production of enamels used for coating metallic surfaces. This procedure addresses challenges such as strong self-absorption and matrix effects, which limit the effectiveness of conventional univariate calibration methods. By employing a multivariate approach, we developed a single model capable of quantifying lithium content across a wide concentration range. A comparison of the LIBS results with those obtained using conventional laboratory analysis (Inductively Coupled Plasma–Optical Emission Spectrometry, ICP-OES) confirms that LIBS can deliver the speed, precision, and reliability required for potential routine applications in the lithium recovery and recycling industry. Full article

Recent updates to European Union directives on drinking water have extended safety limits to hot water, increasing the need to assess materials commonly used in water storage systems, such as porcelain enamel. This study investigates the interaction between enameled surfaces and aqueous environments, focusing on element release and microstructural alterations. The mass loss and chemical stability of the enamel were evaluated through a combination of surface characterization and Inductively Coupled Plasma (ICP) analysis. Time-resolved quantification of selected elements confirmed that all concentrations remained within EU regulatory thresholds. Additionally, the enamel was subjected to acidic and alkaline environments to explore the influence of pH on degradation mechanisms. Scanning electron microscopy (SEM) revealed that while the enamel undergoes surface-level modifications, the bulk structure remains intact. Notably, alkaline exposure had the strongest impact, dissolving needle-like calcium-rich structures and altering the surface more significantly than water or acid alone. These structures appear to facilitate localized corrosion once degraded. The correlation between surface morphology and elemental release dynamics highlights the critical role of microstructural features in determining long-term chemical resistance. Overall, the results underscore the importance of optimizing both the composition and structure of enamel coatings for applications involving prolonged contact with potable water. Full article

Alkyd resins are among the most common coatings used for exterior wood joinery. In Romania, solvent-borne alkyd coatings are widely used to finish wood. The study aims to compare the performance after 7 years of outdoor exposure of two types of alkyd coatings, a semi-transparent brown stain with micronized pigments (Alk1) and an opaque white enamel (Alk2), applied directly on wood or wood pre-treated with three types of resins: acryl-polyurethane (R1), epoxy (R2), and alkyd-polyurethane (R3). Fir (Abies alba) wood served as the substrate. Cracking, coating adhesion, and biological degradation were periodically assessed through visual inspection and microscopy. Additionally, a cross-cut test was performed, and the loss of coating on the directly exposed upper faces was measured using ImageJ. The results indicated that resin pretreatments somewhat reduced cracking but negatively affected coating adhesion after long-term exposure. All samples pretreated with resins and coated with Alk1 lost more than 50% (up to 78%) of the original finishing film by the end of the test. In comparison, coated control samples lost less than 50%. The Alk2 coating exhibited a film loss between 2% and 12%, compared to an average loss of 9% for the coated control. Overall, samples pretreated with alkyd-polyurethane resin (R3) and coated with alkyd enamel (Alk2) demonstrated the best performance in terms of cracking, adhesion, and discoloration. Full article

To address the issue of coating accumulation model failure in unstable environments, this paper proposes a dynamic control method based on visual differential feedback. An image difference model is constructed through online image data modeling and real-time reference image feedback, enabling real-time correction of the coating accumulation model. Firstly, by combining the Arrhenius equation and the Hagen–Poiseuille equation, it is demonstrated that pressure regulation and temperature changes are equivalent under dataset establishment conditions, thereby reducing data collection costs. Secondly, online paint mist image acquisition and processing technology enables real-time modeling, overcoming the limitations of traditional offline methods. This approach reduces modeling time to less than 4 min, enhancing real-time parameter adjustability. Thirdly, an image difference model employing a CNN + MLP structure, combined with feature fusion and optimization strategies, achieved high prediction accuracy: R² > 0.999, RMSE < 0.79 kPa, and σ_e < 0.74 kPa on the test set for paint A; and R² > 0.997, RMSE < 0.67 kPa, and σ_e < 0.66 kPa on the test set for aviation paint B. The results show that the model can achieve good dynamic regulation for both types of typical aviation paint used in the experiment: high-viscosity polyurethane enamel (paint A, viscosity 22 s at 25 °C) and epoxy polyamide primer (paint B, viscosity 18 s at 25 °C). In summary, the image difference model can achieve dynamic regulation of the coating accumulation model in unstable environments, ensuring the stability of the coating accumulation model. This technology can be widely applied in industrial spraying scenarios with high requirements for coating uniformity and stability, especially in occasions with significant fluctuations in environmental parameters or complex process conditions, and has important engineering application value. Full article

Outdoor stone relics, including inscriptions, statues, temple grottoes, etc., are continuously subjected to natural weathering and air pollutants. Those made of marbles and other carbonate rocks are particularly vulnerable to acid rains, which can be protected by acid-resistant coatings. A novel method to prepare enamel-like hydroxyapatite coating on marble surfaces is presented in this paper and analyzed using optical microscopy, a scanning electronic microscope, grazing incident X-ray diffraction, and nano-indentation. The described coating is composed of tightly arranged hydroxyapatite nanorods, perpendicular to the marble substrate, with a thickness of 3–5 μm. Not only does the coating exhibit high acid resistance, it also has considerably higher elastic modulus and hardness compared to that synthesized by the well-known diammonium phosphate (DAP) method owing to the wellarranged microstructure. Consequently, the enamel-like hydroxyapatite coating would probably be more effective and durable for marble protection than the existing calcium phosphate coating. Full article

This work presents the development of a magnetic levitation system with a ferrite core, designed for electromagnetic energy harvesting from mechanical vibrations. The system consists of a fixed enamel-coated copper coil and five neodymium-iron-boron permanent magnets housed within a PVC spool. To enhance magnetic flux concentration, a manganese-zinc ferrite (Mn-Zn) ring was employed within the spool. Experimental tests were conducted at frequencies up to 20 Hz, demonstrating the device’s potential for harvesting energy from small vibrations, such as those generated by human biomechanical movements, achieving operating voltages up to 3 V. Additionally, the architecture is scalable for larger systems and allows for the integration of multiple transducers without magnetic field interference, independent of the frequency or excitation phase of each transducer. Full article