IoT-Based Microclimate and Vibration Monitoring of a Painted Canvas on a Wooden Support in the Monastero of Santa Caterina (Palermo, Italy)

The main objective of this work is the characterization and observation of the performance of an IoT measurement and monitoring system in the field of cultural heritage conservation for assessing the health condition of artworks. This article also describes the application of this system to the monitoring of a canvas painting applied on a wooden support, an artwork from the 19th century by the painter Giuseppe Patricolo depicting The Deposition, placed inside a niche in the Santa Caterina Monastery in Palermo (Italy). Considering the presence of the wooden structure, it is useful to measure not only microclimatic parameters such as temperature and humidity, but also vibrations that can in fact cause degradation phenomena in these artworks. This is a first step towards the development of mimetic systems integrated in the work of art without causing physical, mechanical or chemical alterations and ensuring that the level of microclimatic parameters is below the threshold values whose exceeding could compromise the entire artefact

Effect of Particle Size on Pigments Colour

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Historical building dating: A multidisciplinary study of the Convento de São Francisco (Coimbra, Portugal)

Cross-dating of bricks and mortars from historical building, through thermal (TL) and optically stimulated (OSL) luminescence have achieved good accuracy and precision. However this approach is, in many cases, not exhaustive especially for buildings with different construction phases closely temporally spaced to each other. The uncertainties of experimental data added to the reuse of old bricks and/or the presence of mortars applied on restorations represent the main limits to obtain the complete chronology. In the case of the Convento de S. Francisco (Coimbra, Portugal), the dating results were crossed with the stratigraphic study of the building, mineralogical characterization by XRD and colorimetric data of the mortar samples. Thanks to luminescence ages, mineralogical composition and color specification, two phases of construction were identified: the first from the 17th century and the first half of the 18th century and the second from the second half of the 18th century to the first half of the 19th century. These results were confirmed by mineralogical characterization and colorimetric measurements of mortars that identify two different types of materials in aggregate/binder ratio terms and superficial optical characteristics

Investigation by pXRF of Caltagirone Pottery Samples Produced in Laboratory

In the study of archaeological ceramics, it is important to have compositional data to identify their origin and source. The fabric also provides useful information on the production technology, especially with regard to the firing steps. The work presented here is connected to this field and focuses on the main parameters related to the terracotta artefacts preparation. Thus, one can consider the effects in terracotta characteristics of different raw materials and firing parameters, in particular for pottery of Caltagirone, which is one of most important centres of pottery production in Italy, active since the Neolithic. To this end, terracotta samples have been reproduced in a laboratory setting according to the ancient procedure of Caltagirone manufacture, starting from clay and degreaser extraction in local historical sites. The analysis was conducted using a portable X-Ray Fluorescence (pXRF) spectrometer for elemental characterization of sand degreaser and of clays during each step of the realization process and in different firing conditions. SEM-ED techniques were also employed to verify the method and results for some of the samples after firing process. Framing the technological context of manufacture production, known in the specific case, it is also possible to identify potential outcomes and limits in the study of potsherds using pXRF technology, in applying the methodology to historic artefacts

Absorbed Dose Evaluation in Radioiodine Therapy with Different Approaches

The main approach to differentiated thyroid cancer (DTC) therapy is still empiric, consisting of the administration of fixed activities. Repeated treatments, however, may have a stunning effect. An individualized dosimetric study may represent an important tool to determine the best activity to prescribe, in particular for patients with distant metastases or when therapy with recombinant human thyroid-stimulating hormone (rhTSH) stimulation is deemed necessary. This study provides a practical operational example for carrying out a dosimetric study, according to the European Directive EURATOM/59/13. Starting from the case of a patient who underwent rhTSH stimulation before radioiodine ablation, we illustrate the necessity of measuring both red marrow (RM) and blood (BL) absorbed dose during the treatment in order to not exceed the dose limit of 2 Gy to the RM, so as to avoid repeating radioiodine treatment several times. Dosimetry to the RM and BL was performed during the treatments, after administration of therapeutic activity without modifying the fixed activity schema, using different approaches. The results suggest the possibility of restricting the number of treatments, reducing thus the risk of stunning effect and, where possible, eliminating an additional source of stress and dejection for patients

NUCLEAR MAGNETIC RESONANCE RELAXOMETRY AND IMAGING FOR DOSIMETRY WITH AGAROSE FRICKE GEL

Introduction: Fricke Xylenol Gel (FXG) dosimetric system is based on the radiation induced oxidation of ferrous to ferric ions. In this kind of gels it can occur that ferrous and ferric ions diffuse in the gel matrix. To preserve the spatial distribution of the dose from diffusion, Fricke gels must be undergoing measurement within a few hours of their irradiation. Thus, the spatial integrity of the dose distribution in the Fricke gel is maintained. The oxidation of ferrous ions also causes a reduction of the longitudinal nuclear magnetic relaxation time which can be measured by means of nuclear magnetic resonance (NMR) instrumentation. In this work we performed NMR relaxometry and MR imaging investigations of Fricke Xylenol Gel characterized by gelatinous matrix of Agarose for possible applications in clinical photon beams used for radiation therapy. Materials and Methods: NMR relaxometry measurements were performed using an mq-ProFiler single-side relaxometer (Bruker Biospin). MRI imaging was realized on a 1.5 T Achieva scanner (Philips) with an eight channel head coil. The gels were irradiated in the clinical dose range (0– 20 Gy) with a Siemens Primus Low linear accelerator. Results: The main dosimetric features of the NMR signal were investigated. The linearity of the response with dose was observed. In order to assess the photon sensitivity we analyzed the dependence of NMR relaxation time on radiation dose with varying ferrous ammonium sulfate content inside FXG. The ferrous ammonium sulfate content which maximizes sensitivity is 1.75 mM. Furthermore, signal stability was followed for several days after irradiation. Aldo for MRI analysis the dose calibration curves were obtained also with MRI scanner. Moreover, a depth dose profile was reconstructed. Conclusions: We can conclude that FXG dosimeters with optimal ferrous ammonium sulfate content can be regarded as a valuable dosimetric tool to achieve fast information on spatial dose distribution