Paints on cultural heritage objects with low binder content tend to be porous and can show low internal cohesion. The morphology and spatial distribution of the binder remain largely uncharacterised, despite their expected importance for the mechanical integrity of such paints. This study presents the first three-dimensional nanoscale images of a pure organic binder network within historic porous paint samples obtained using ptychographic X-ray computed tomography (PXCT). The samples consist of a proteinaceous binder and synthetic ultramarine blue pigment. The binder, although occupying at most 7.1% of the sample volume, forms an interconnected network with locally pore-filling clusters and with large binder–pigment contact areas. These observations suggest a microstructural explanation for how cohesion, although limited, can arise in highly porous paints with low binder fractions. PXCT has proven to be a powerful method for visualizing binders in heterogeneous porous composite paints, enabling future research relevant to their preservation.
The earliest native copper coins of the Korean Peninsula were first minted in the Koryŏ Dynasty. Morphologically and epigraphically, these coins share notable similarities to contemporary Chinese Song Dynasty copper coins. This study employs X-ray fluorescence spectrometry to characterize the metal composition of 36 Koryŏ copper coins. The results show that their copper content fluctuates approximately from 60.95 wt.% to 92.57 wt.%, lead content from 0.11 wt.% to 24.45 wt.%, and tin content from 1.87 wt.% to 23.85 wt.%. The coins are bronze specimens consisting primarily of copper, lead and tin, yet their alloy ratios are highly variable and inconsistent. When compared with Song Dynasty coin alloy recipes, the analyzed samples exhibit marked compositional divergence, indicating distinctive alloying practices and an independent minting tradition for Koryŏ copper coinage.
Repeated assessment of moisture content is essential for the preventive conservation of open-air earthen sites, yet conventional contact-based methods cannot readily provide dense spatial coverage. This study proposes a non-destructive method that predicts surface moisture content from chromatic features. A laboratory reference model was first developed using normalized RGB features (R_norm, G_norm, B_norm) that are insensitive to illuminance variation, and the model was then adapted to complex field lighting conditions through transfer learning. The transferred model yielded high prediction accuracy for the silty clay and silt tested in this study under conditions of low surface roughness (PEDI ≤0.3). Within the tested conditions, this workflow enables low-cost, non-contact assessment of surface moisture content and offers a practical tool for the field investigation and preventive conservation of open-air earthen sites.
Termite damage to wooden architectural heritage is a growing concern under climate change, yet no assessment exists for North Korea, where field survey is currently impractical. Framed within the hazard-exposure-vulnerability paradigm of heritage risk assessment, we integrated climate data, GIS-based spatial analysis, a biological model of termite-driven wood decay, and regression analysis to assess risk to 67 heritage sites. Termites can potentially inhabit 62.1% of the land area, and 64 sites (95.5%) fall within this range, with an estimated above-ground activity period of 195.2 days. Using the Relative Termite Damage Potential Index and Jenks natural breaks, habitable sites were classified as 15 low-, 32 moderate- and 17 high-risk, and every World Heritage component in the country fell in the high-risk class. Regression on location explained 86.4% of the variance, risk increasing toward lower latitudes. This first assessment offers a transferable risk-assessment framework for heritage in regions with poor access.
The existing minimal intervention evaluation system for historical buildings lacks a unified quantitative evaluation framework that can be effectively applied at different spatial scales. This study takes 9 typical historical buildings along the central axis of Beijing, and constructs a three-dimensional evaluation framework of “Authenticity protection, Moderate intervention, Value continuity.” Using AHP to determine the weights of each indicator, combined with fuzzy evaluation method to quantify the minimal intervention level of the case. This study focuses on analyzing spatial scale differences, differentiation of case features at the same scale, and the correlation between the three dimensions. The AHP weights are consistent with the evaluation results, verifying the scientific and scenario adaptability of the evaluation framework. The unified quantitative evaluation framework established and its application results at multiple scales provide practical tools for the minimal intervention protection of historical buildings at different scales under the same cultural background.
