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Chemical and lead isotope characterisation was carried out on shrapnel balls and bullets dating back to the First World War (WWI). These ammunitions were widely utilised in the Alpine Austrian–Italian front located in the Italian Alps. The investigation has been performed using inductively coupled plasma quadrupole mass spectrometry equipped with an octopole reaction system (ORS-ICP-QMS). The main goal of this work was to identify the elemental and lead isotope composition of raw materials and to discriminate between the military objects analysed. The results of multi-elemental analysis indicate that the shrapnel ball samples consisted of soft Pb or hard Pb with Sb depending on the use, the weapon type and the specific nation. The Italian shrapnel balls were made from hard Pb, as opposed to those of the Austrian–Hungarian samples. Through the investigation of lead isotope ratios, it has been possible to differentiate most of the Italian shrapnel balls from those of Austrian–Hungarian origin. Furthermore, some Italian shrapnel balls had a different lead isotope composition depending on their calibre. The elemental composition and lead isotopic signature of bullets show a clear discrimination between the external jacket and the core in relation to projectile type and nationality. The bullet cores consist of Pb–Sb alloy regardless of the region of origin. This work allowed us to investigate the potential applications of trace elements and lead isotope analyses to discriminate military artefacts of different origins.

In recent years, Cr3+-activated phosphors have been attracting a lot of interest due to their unique optical features that can be exploited for applications ranging from lasers to optical thermometry, near-infrared (NIR) emitting phosphors for bioimaging and NIR-LEDs, to name a few. Despite the interesting optical properties shown by Cr3+-doped Ga2O3, investigations are limited only to β-Ga2O3 and α-Ga2O3 polymorphs. Using mesoporous silica particles with different pore sizes between 3 nm and 22 nm as nanoreactors, cubic γ-Ga2O3:Cr3+ spinel nanocrystals (NCs) are stabilized through confinement into the mesopores as confirmed by HR-TEM, XRPD and the photoluminescence spectral shape. A detailed spectroscopic investigation in the temperature range between 16 to 500 K allowed extrapolating the fundamental parameters in the framework of the Tanabe–Sugano diagram and comparing the values for Cr3+ in γ-Ga2O3 with the α- and β-phases. In addition, due to the confinement of the NCs into the silica structure, the phase transition to the β-phase, conventionally occurring at about 700 °C, is hindered up to 1000 °C, improving the stability of the γ-Ga2O3 phase. [ABSTRACT FROM AUTHOR]

Gian Giacomo Inchiocchio (1604–1656), better known as Barbelli, was one of the main exponents of Lombard painting of the seventeenth century. A large body of work is attributed to him, encompassing a wide range of drawings, murals, and oil paintings. However, despite his broad production, there are still many open questions regarding his painting techniques and materials. In this paper, a multi-analytical study of the cycle Stories of the life of Saint George that originally decorated the presbytery of the parish church of Casaletto Vaprio (Cremona, Italy) was performed, combining non-invasive techniques with the characterisation of selected micro samples. Results show that Barbelli used a very limited number of inorganic pigments, often mixing them together to create different colours and shades. Remains of caseinate and degradation products (i.e. weddellite and whewellite) related to the strappo intervention were also highlighted. The study helped to decipher the materials and technique of this painting, providing data that can be used as a reference to study his extensive production. [ABSTRACT FROM AUTHOR]

From natural erosion to pollution-accelerated decay, stone cultural heritage deteriorates constantly through interactions with the environment. Common protective treatments such as acrylic polymers are generally prone to degradation and loss of performance, and they are often limited in their ability to achieve uniform and conformal coverage across a stone's topographical features. In this work, atomic layer deposition (ALD) was explored to address these issues by growing protective amorphous alumina coatings on compact carbonate (Istria) stone. ALD protective coatings, unlike coatings produced by traditional methods, do not significantly alter morphology by filling open pores or accumulating on the surface in more compact areas. Our morphological and spectroscopic investigations revealed that the ALD alumina films deposited uniformly over the surfaces of Istria stone, without significantly altering the topography or appearance. The protective effects of the ALD coatings were investigated by aqueous acid immersion. The solution pH, along with the Ca2+ concentration, was tracked over time for a constant volume of acetic acid solution with an initial pH of 4 with the stone samples immersed. We found that the protective effects of ALD alumina coatings were extremely promising, slowing the average rate of pH evolution significantly. The eventual failure of the ALD coatings during immersion was also investigated, with interesting morphological findings that point to the role of defects in the coatings, suggesting new directions for improving the use of ALD coatings in future research and applications. [ABSTRACT FROM AUTHOR]

The combination of the ability to absorb most of the solar radiation and simultaneously suppress infrared re-radiation allows selective solar absorbers (SSAs) to maximize solar energy to heat conversion, which is critical to several advanced applications. The intrinsic spectral selective materials are rare in nature and only a few demonstrated complete solar absorption. Typically, intrinsic materials exhibit high performances when integrated into complex multilayered solar absorber systems due to their limited spectral selectivity and solar absorption. In this study, we propose CoSbx (2 < x < 3) as a new exceptionally efficient SSA. Here we demonstrate that the low bandgap nature of CoSbx endows broadband solar absorption (0.96) over the solar spectral range and simultaneous low emissivity (0.18) in the mid-infrared region, resulting in a remarkable intrinsic spectral solar selectivity of 5.3. Under 1 sun illumination, the heat concentrates on the surface of the CoSbx thin film, and an impressive temperature of 101.7 °C is reached, demonstrating the highest value among reported intrinsic SSAs. Furthermore, the CoSbx was tested for solar water evaporation achieving an evaporation rate of 1.4 kg m−2 h−1. This study could expand the use of narrow bandgap semiconductors as efficient intrinsic SSAs with high surface temperatures in solar applications. The efficiency of CoSbx (where 2 < x < 3) as a selective solar absorber is investigated. Here, authors demonstrate that CoSbx endows broadband solar absorption (0.96) and simultaneous low emissivity (0.18), making it a promising material for use in solar energy systems. [ABSTRACT FROM AUTHOR]