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This paper investigates the durability of geopolymers and geopolymeric mortars made with metakaolin and alkaline activators, with and without a coconut fiber addition, after immersion for seven days into solutions of citric acid (1%, 2.5%, 5%, and 10%); hydrochloric acid (1%, 2.5%, 5%, and 10%); and sulfuric acid (1%, 2.5%, 5%, and 10%). The study focuses on mass changes, uniaxial compressive strength, flexural strength, and ultrasound pulse velocity measurements. X-ray diffraction and scanning electron microscopy are used to analyze the degradation products and microstructural changes. The aim is to assess the effect of acid exposure on the strength and stability of geopolymer materials and identify any protective effects of coconut fiber reinforcement. The samples are immersed in acid solutions of varying concentrations, and their mechanical properties are measured. The presence of coconut fibers slightly modifies the physical properties and the compressive strength, improving the mechanical flexural strength. Geopolymer and geopolymeric mortar materials experienced a weak decrease in strength when exposed to solutions of citric acid and a significant one when exposed to solutions of hydrochloric and sulfuric acids, attributed to depolymerization of the aluminosilicate binders. Brick waste geopolymeric mortars reinforced with coconut fibers showed the best performance in acid solutions with respect to geopolymers and quartz-rich sand geopolymeric mortars, suggesting a more stable cross-linked aluminosilicate geopolymer structure in this material.

Soluble salts are compounds found inside ornamental rocks and building stones exposed to atmospheric agents in environments rich in alkaline metal ions, such as sodium and potassium. The damage induced by their crystallization in those materials, used to build monuments and architectural structures of great importance, is an unsolved problem. Sodium sulfate is one of the most common and harmful salt found in these constructions. In this work, we studied the resistance through time to the wet-drying cycles of some natural stones (calcarenites, marbles, and sandstones) that have been utilized in the historical architecture in Italy. Samples were freshly cut and thermally aged to simulate increasing decay. Induced porosity in the thermally degraded samples was high in calcarenites, medium in marbles, and low in sandstones. Specimens subjected to artificial thermal aging lost a major percentage of mass compared to the non-weathered ones, when affected by the crystallization of soluble salts. With this study, we have observed that samples subjected to different wetting and drying cycles degrade faster due to the action of soluble salts, compared to samples that are not subjected to these cycles.

This study presents the petrographic and chemical characterization of the frescoes in the Church of San Panfilo in Tornimparte (AQ, Italy) by Saturnino Gatti, a prominent painter of the late 15th–early 16th century, known for his exquisite technique, composition, and use of color. The characterization of the frescoes is essential for understanding the materials and techniques used by Gatti, as well as for identifying the stratigraphy and painting phases. Eighteen samples were collected from the original paint layers, later additions (17th century), and restored surfaces, and analyzed by optical microscopy, cathodoluminescence microscopy, scanning electron microscopy (SEM-EDS), μ-Raman, and electron paramagnetic resonance (EPR). The analyses revealed a microstratigraphy often made of three main layers: (1) preparation, consisting of lime plaster and sand; (2) pigmented lime, applied by the fresco technique; and (3) additional pigmented layer on the surface. The most often recurring pigments are black, red, yellow (all generally linked with the fresco technique), and blue (applied “a secco”). The presence of two painting phases was also noted in one sample, probably resulting from a rethinking or restoration. These findings contribute to the understanding of the history and past restoration works of this cultural heritage site, providing important insights not only for conservators and restorers, but also for a broader understanding of Italian fresco painting and art history of the late 15th and early 16th centuries.

In this work, a critical review of the current nondestructive probing and image analysis approaches is presented, to revealing otherwise invisible or hardly discernible details in manuscripts and paintings relevant to cultural heritage and archaeology. Multispectral imaging, X-ray fluorescence, Laser-Induced Breakdown Spectroscopy, Raman spectroscopy and Thermography are considered, as techniques for acquiring images and spectral image sets; statistical methods for the analysis of these images are then discussed, including blind separation and false colour techniques. Several case studies are presented, with particular attention dedicated to the approaches that appear most promising for future applications. Some of the techniques described herein are likely to replace, in the near future, classical digital photography in the study of ancient manuscripts and paintings. Keywords: Image analysis, Cultural heritage, Archaeology, Multispectral imaging, Ancient manuscripts, Blind separation techniques

The quarrying of marble and its processing to produce building materials often generates a negative impact on the environment. In the Apuan Alps marble district, a renowned quarrying area in Italy since ancient times, the aquatic pollution of water bodies, caused by the presence of marble waste in the form of powder or sludge, represents a significant and current environmental problem. Depending on the different national and international regulations on waste management, the marble waste can be classified as a special non-hazardous industrial waste. If marble waste has been managed according to environmental international and national laws, it can be reused as a by-product. For this, the present work aims to evaluate the reuse of marble waste as a material in replacement for cement for producing mortars. Subsequently, the mechanical and physical tests were carried out to evaluate the specific properties of the obtained materials during and after the curing time. The results showed that replacement of cement into mortars by marble waste always causes a decrease of mechanical properties, with still acceptable values for many applications up to a substitution of less than 25%. From the collected data, the use of marble waste in the production of cement mortars represents an adequate and sustainable destination of this by-product.

This work proposes a methodology of digital analysis of the state of conservation of a canvas painting to solve difficulties related to the pictorial reintegration of paintings that present an excessive number of different lacunae in terms of size and extent. The case study is related to the small-size oil on canvas painting executed by an unknown artist, where the lacunae were challenging to analyze and localize graphically. Therefore, it required a careful evaluation of the approach to be used during the pictorial reintegration intervention. Using an image analysis method, based on the semi-automatic extraction approach, the state of conservation’s graphic relief outlining different virtual operating proposals was obtained.

Digital images represent the primary tool for diagnostics and documentation of the state of preservation of artifacts. Today the interpretive filters that allow one to characterize information and communicate it are extremely subjective. Our research goal is to study a quantitative analysis methodology to facilitate and semi-automate the recognition and polygonization of areas corresponding to the characteristics searched. To this end, several algorithms have been tested that allow for separating the characteristics and creating binary masks to be statistically analyzed and polygonized. Since our methodology aims to offer a conservator-restorer model to obtain useful graphic documentation in a short time that is usable for design and statistical purposes, this process has been implemented in a single Geographic Information Systems (GIS) application.

The production of a plasma by a pulsed laser beam in solids, liquids or gas is often associated with the generation of a strong shock wave, which can be studied and interpreted in the framework of the theory of strong explosion. In this review, we will briefly present a theoretical interpretation of the physical mechanisms of laser-generated shock waves. After that, we will discuss how the study of the dynamics of the laser-induced shock wave can be used for obtaining useful information about the laser−target interaction (for example, the energy delivered by the laser on the target material) or on the physical properties of the target itself (hardness). Finally, we will focus the discussion on how the laser-induced shock wave can be exploited in analytical applications of Laser-Induced Plasmas as, for example, in Double-Pulse Laser-Induced Breakdown Spectroscopy experiments.

In this communication a representation of the links between DNA-relatives based on Graph Theory is applied to the analysis of personal genomic data to obtain genealogical information. The method is tested on both simulated and real data and its applicability to the field of genealogical research is discussed. We envisage the proposed approach as a valid tool for a streamlined application to the publicly available data generated by many online personal genomic companies. In this way, anonymized matrices of pairwise genome sharing counts can help to improve the retrieval of genetic relationships between customers who provide explicit consent to the treatment of their data.