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First successful Brazilian case of consolidation of a polychrome wooden sculpture using ionizing radiation
2025 - OLIVEIRA, MARIA J.A. de; PEREIRA, MARIA A.M.G.; FERNANDES, VAGNER; JESUS, ANDERSON G. de; PIRES, ADRIANA; VALLEGO, RACHEL; VASQUEZ, PABLO A.S.
This study evaluates the effectiveness of a consolidation treatment using ionizing radiation and a polyester–styrene resin applied to a polychrome wooden sculpture of Saint Jerome severely damaged by insect attack. The artwork, belonging to the Museum of the Palácio dos Bandeirantes (São Paulo, Brazil), was characterized using non-destructive imaging techniques, including radiography and tomography. Resin impregnation was performed in a custom stainless-steel vessel operating under vacuum and positive pressure. The sculpture was then treated with gamma radiation to a total absorbed dose of 50 kGy. The treatment achieved full structural consolidation, allowing safe restoration and suitability for exhibition.
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Reversible polymeric resin cured by ionizing radiation for consolidation of wooden artifacts of cultural heritage
2025 - OLIVEIRA, MARIA J.A. de; ARAUJO, MARIANA; OTUBO, LARISSA; MELLO-CASTANHO, SONIA; VASQUEZ, PABLO
This study investigated the application of Paraloid B72 resin, modified with methyl methacrylate (MMA) and butyl methacrylate (MaBu) monomers, to develop new materials for the consolidation and restoration of wooden objects. The curing process was conducted using ionizing radiation from a gamma source (cobalt-60), eliminating the need for organic solvents. After characterization by gel fraction analysis, the Paraloid 30 % formulation with MMA 40 % and MaBu 30 % was selected for further characterizations, including Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), and impregnation tests. The formulation was impregnated into wooden artifacts, cured using ionizing radiation, and subsequently characterized by FTIR, Scanning Electron Microscopy (SEM), and Computed Tomography (CT). The results showed that ionizing radiation replaces the need for catalysts, increasing the thermal stability of the resin and allowing cure control through dose (in kGy) and dose rate (kGy/h). This enabled the resin impregnation without compromising the integrity or the information contained in the consolidated artifact. The development of the methodology and resin formulation presented scientific challenges, particularly in ensuring that the desirable characteristics and reversibility were maintained.
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A derivation of Judd-Ofelt theory by second quantization of configuration interaction
2026 - BLOIS, LUCCA; LONGO, RICARDO L.; CARNEIRO NETO, ALBANO N.; FAUSTINO, WAGNER M.; MOURA JR, RENALDO T.; FELINTO MARIA C.F.C.; BRITO, HERMI F.; MALTA, OSCAR L.
A derivation of the equations in the Judd-Ofelt theory for quantifying the intensities of 4f-4f transitions based on the second quantization or occupation number representation is presented. This derivation is more concise and compact, emphasizing some approximations employed and aims at simplifying the comprehension of the theory. It is almost self-contained, with the properties and relationships pertaining to the second quantization approach being introduced, and it requires some basic understanding of quantum mechanics, particularly, of angular momentum techniques (e.g. 3-j symbols and Racah operators). It is expected that this derivation can be followed and comprehended by students, researchers, and enthusiasts, hopefully encouraging new implementations, applications, and developments involving the intensities of 4f-4f transitions.
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Occurrence and potential ecological risks of pharmaceuticals and illicit drugs (PhIDs) in the Santos-Sao Vicente Estuarine System (SSVES), Brazil
2025 - ORTEGA, ANDRESSA dos S.B.; ROVERI, VINICIUS; PAÇO, MARINA de S.; LEBRE, DANIEL T.; MARANHO, LUCIANE A.; PEREIRA, CAMILO D.S.
Despite the substantial amount of research on the presence of pharmaceuticals and illicit drugs (PhIDs) in freshwater environments, there is a paucity of data on these contaminants in estuarine systems, particularly in South America. Industries, the biggest port in the Southern Hemisphere, and substantial urban areas surround the Santos-S & atilde;o Vicente Estuarine System (SSVES), located in a Brazilian subtropical area. This study constitutes the first assessment of contamination by PhIDs in this estuarine area. Samples of superficial water, sediments, and oysters were analyzed through liquid chromatography-tandem mass spectrometry (LC-MS/MS). Furthermore, the potential ecological risk to aquatic non-target organisms (i.e., primary producers, primary and secondary consumers) was assessed using the maximum measured environmental concentrations (MEC) of the PhIDs identified in this study. The results revealed the widespread presence of caffeine (MEC = 72.1 ngL-1) > losartan (29.6 ngL-1) > orphenadrine (25.9 ngL-1) > benzoylecgonine (18.6 ng/L-1) > carbamazepine (7.4 ngL-1) and cocaine (3.6 ngL-1). These findings were obtained from relevant sites at SSVES, near areas with mangroves and anthropogenic activities, such as fishing and swimming. Consequently, the ecological risk assessment indicated significant environmental concern, as our results suggested low to moderate risks of all compounds to algae, crustaceans, and/or fish. Considering the One Health approach, further studies are recommended to investigate the potential human health risks associated with consuming contaminated seafood. Concomitantly, there is an urgent need for improvements in public sanitation, public health care for illicit drug users, and public safety actions against traffic.