Search Results (6)

Historic buildings represent a substantial share of the European building stock. However, their energy retrofit is heavily restricted by conservation principles that often exclude conventional insulation systems. In this context, phase change materials (PCMs) incorporated into lime-based mortars have emerged as a potentially compatible solution, combining latent heat storage capacity with the compatibility traditionally associated with aerial lime, the binder of reference in conservation practice. In some cases, natural hydraulic lime and hydrated lime are also used in heritage conservation applications. The aim of this study, therefore, is to provide a systematic review of peer-reviewed articles published between 2010 and 2026 that illustrate the use of PCM-containing lime mortars applied in historic buildings. The analysis examines PCM types, incorporation methods, thermal and mechanical behavior, durability, and compatibility with conservation requirements. The reviewed studies demonstrate that the incorporation of PCM generally reduces internal thermal fluctuations in buildings along with capillary water absorption. Durability investigations indicate improved resistance to freeze–thaw cycles and salt crystallization of mortars containing such PCMs. However, durability was investigated in less than 20% of the studies reviewed. Lime mortars show a consistent reduction in compressive strength as the PCM content increases; on the other hand, hydrated lime mortars can also offer increases in strength. Although the reviewed studies focused on applications in historic buildings, the reversibility of the intervention and its compatibility with historic substrates was not assessed according to the standards required for the conservation of cultural heritage. This gap represents the main limitation of the research conducted. Full article

This study introduces a modular approach to the validation of non-invasive coating inspection. It involves RGB imaging, visible and near-infrared spectroscopy, measurements of the physical parameters of the coating, and 3D Gaussian Splatting. As publicly available datasets containing these different types of information for the same coating samples are rare, each module was considered separately. The study also defines the type of paired data required for future data-fusion experiments. During the analysis of the painted-metal image dataset, exact-file hashing identified 68 duplicate images shared between the training and test sets. After removing these images and the duplicates within the test set, the best fixed $48\times 48$ image classifier achieved an accuracy of 78.49% and a balanced accuracy of 78.99% on 93 distinct test images. In addition, an additional sensitivity analysis was conducted using an ImageNet-pretrained EfficientNetB0 model with $224\times 224$ images. This model achieved an accuracy of 66.67%. This result shows that higher-resolution images and a pretrained model do not directly improve performance on a small and domain-specific dataset. Coated-wood defect localization, controlled steel-defect detector comparison, duplicate-grouped ship-coating spectroscopy, public gloss, roughness, scanning-electron-microscopy workbooks, and reflective-scene reconstruction were recomputed as separate validation blocks. The reflective-scene reconstruction achieved a peak signal-to-noise ratio of $25.018\mathrm{dB}$, a structural similarity index of $0.8947$, and a learned perceptual image patch similarity value of $0.1522$. However, camera distortion and unidirectional geometry limitations restrict this module to feasibility analysis. Our framework provides reproducible baselines and defines the paired-data requirements for future calibrated coating-monitoring systems. Full article

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

Bamboo surfaces are susceptible to scratches and contamination during service, which limits their durability and aesthetic performance. To address this issue, this study aims to develop a natural self-healing coating based on tung oil microcapsules. Tung oil microcapsules encapsulated within chitosan and gum arabic (TO/CS–GA MCs) were prepared by spray drying at two feed rates (100 and 200 mL h⁻¹) and incorporated into tung oil coatings applied on bamboo substrates. The effects of microcapsule content (1.0–11.0 wt%) and feed rate on the optical performance, mechanical performance, and self-healing performance of the coatings were systematically investigated. The results showed that increasing the microcapsule content gradually increased the color difference (ΔE) and surface roughness of the coatings, while the gloss decreased. The hardness, impact resistance, adhesion grade, and self-healing efficiency of the coatings exhibited a similar trend, initially increasing and then decreasing with increasing microcapsule content. This behavior indicates that an appropriate amount of microcapsules can enhance the coating performance, whereas excessive addition leads to particle agglomeration and structural defects. Under the better condition of 5.0 wt% microcapsule content and a spray-drying feed rate of 100 mL h⁻¹, the coating exhibited the best overall performance, including higher gloss retention, a hardness of 2H, an impact resistance of 3 kg·cm, relatively low surface roughness, and a self-healing efficiency of 28.16 ± 0.63%. These results suggest that the spray-drying feed rate plays an important role in regulating the particle size distribution and encapsulation efficiency of the microcapsules, which in turn affects their dispersion and rupture–release behavior within the coating matrix. Therefore, controlling the spray-drying parameters is crucial for optimizing the performance of microcapsule-based self-healing coatings. Overall, this study provides a sustainable strategy for developing natural polymer-based self-healing coatings and offers useful insights into the design of functional microcapsules for bamboo surface protection. Full article

Qiangduo Tibetan paper is a typical intangible cultural heritage in the Shangri-La region of Yunnan, China, mainly handmade from two local fibrous plants, Stellera chamaejasme and Wikstroemia canescens. This study focuses on the correlations among its surface properties, water absorption and dry heat durability, which are critical for heritage conservation. Four paper samples (Z1–Z4) were investigated via micromorphology, physicochemical property testing and dry heat aging (105 °C, 216 h). The results show that the two raw materials lead to distinct fiber and pore structures: Stellera chamaejasme paper has coarser fibers and loose pores, while Wikstroemia canescens paper has finer and denser fibers. All samples present a near-neutral to weakly alkaline pH (6.87–7.56) and favorable water absorption, jointly regulated by fiber structure and alkaline wood ash fillers. After dry heat aging, all samples undergo whiteness loss, tensile index decay and slight acidification, with extremely significant changes (p < 0.001). Notably, Stellera chamaejasme paper exhibits much higher aging resistance, with whiteness and tensile index retention reaching 77.97%–93.07% and 71.46%–74.77% respectively, far superior to Wikstroemia canescens paper. The mechanism lies in the high flavonoid content and low lignin level in Stellera chamaejasme fibers, which enhance antioxidant stability and reduce yellowing, whereas the opposite composition accelerates degradation in Wikstroemia canescens paper. This study provides a scientific basis for the conservation, inheritance and targeted application of Qiangduo Tibetan paper, supports the sustainable protection of handmade paper cultural relics, and enriches the application of surface science in cultural heritage conservation. Full article

Conventional adhesives for plywood are mostly derived from petroleum-based materials and commonly suffer from formaldehyde emission, posing threats to the environment and human health. In this study, a renewable resource, Xanthoceras sorbifolium Bunge oil, was used as the raw material. A high-performance bio-based adhesive was successfully prepared by synthesizing Xanthoceras sorbifolium Bunge oil dimethacrylate (MXOEA) as a reactive diluent, blending it with acrylated epoxy Xanthoceras sorbifolium Bunge oil (AEXO), and introducing 2-isocyanatoethyl methacrylate (IEM) to enhance crosslinking. The effects of the MXOEA/AEXO ratio and the IEM addition level on the properties of the adhesive and the resulting plywood were systematically investigated. The results showed that when the mass ratio of AEXO to MXOEA was 3:7, and the IEM content was 10%, the adhesive exhibited the best bonding performance: the resulting plywood achieved a modulus of rupture of 68.85 MPa, a modulus of elasticity of 8086 MPa, and dry and wet bonding strengths of 3.21 MPa and 2.32 MPa, respectively. Mechanistic analysis indicated that the introduction of IEM moderately reduced the viscosity of the adhesive system. Meanwhile, the isocyanate groups in IEM reacted with the hydroxyl groups on the wood surface, forming a chemical crosslinking structure at the adhesive-wood interface, which is considered one of the reasons for the improved mechanical properties of the plywood. This study provides a formaldehyde-free, high-performance bio-based adhesive derived from Xanthoceras sorbifolium Bunge oil for the field of wood-based composites. Full article