85 research outputs found
Characterization of Soluble Salts on the Frescoes by Saturnino Gatti in the Church of San Panfilo in Villagrande di Tornimparte (L’Aquila)
No full textSalt crystallization is one of the most dangerous forms of degradation affecting frescoes.
This phenomenon can lead to cracking, flaking and detachment of the pictorial layer, ultimately ruining the work of art. However, the characterization of soluble salts via chemical analysis can be employed to determine the conditions of the artifact and establish the proper restoration and/or conservation strategies to be adopted. In this archaeometric study, a first-ever characterization of the soluble salts and related degradation phenomena on the frescoes by Saturnino Gatti in the church of San Panfilo in Villagrande di Tornimparte (L’Aquila) was carried out. Sampling was performed in areas with evident detachments, exfoliations and saline crystallization (efflorescences). Eleven samples of powder and fragments were taken from different panels of the fresco: nine were taken from Panels A, C, D and E and two from the top part of the vault. Chemical characterizations were performed using two analytical techniques: ion chromatography (IC) and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR). Ion chromatography was used for the quantification of the main ions and to evaluate the presence of soluble salts, whereas infrared spectroscopy was used to characterize the mineralogical phases. The results show efflorescence consisting of newly formed gypsum and carbonate in samples taken closer to the ground. Furthermore, a good correlation between sodium and chloride ions was observed, indicating the presence of an efflorescence composed of newly formed sodium chloride. Capillary rise and infiltration were highlighted as the main sources of soluble salts. This information will be crucial in guiding future restoration or conservation operations
Geografia della fame: sessanta anni dopo!
No full textThe issue regarding the contrast between the potential population growth and the
potential increase in sustenance (alias, food supply) is as old as time. At the beginning of
the Fifties a book entitled “The Geography of Hunger” was published; the author, Josuè De
Castro, took stock of the multiple questions regarding the issues deriving from hunger and
malnutrition immediately after the Second World War. Since then, after about sixty years,
despite reality has experienced remarkable changes, the issue of hunger is still a living
matter. The following article will examine the “state” of World hunger as well as explore a
range of feasible solutions and strategies aiming at reaching a sustainable economic growth
in developing countries. The article will argue that the common denominator of all these
solutions and strategies is investing in productive, innovative and sustainable agriculture.La questione del contrasto tra la crescita potenziale della popolazione e il potenziale aumento del sostentamento (alias, approvvigionamento alimentare) è vecchio come il tempo. All'inizio degli anni Cinquanta viene pubblicato un libro intitolato “La geografia della fame”; l'autore, Josuè De Castro, ha fatto il punto sulle molteplici domande riguardanti i problemi derivanti dalla fame e malnutrizione subito dopo la seconda guerra mondiale. Da allora, dopo circa sessant'anni, nonostante la realtà abbia subito notevoli cambiamenti, il problema della fame è ancora vivo. Il seguente articolo esaminerà lo "stato" della fame nel mondo e esplorerà una gamma di soluzioni praticabili e strategie volte a raggiungere una crescita economica sostenibile nei paesi in via di sviluppo. L'articolo sosterrà che il denominatore comune di tutte queste soluzioni e strategie sta investendo in un'agricoltura produttiva, innovativa e sostenibile
Multitechnique diagnostic analysis and 3D surveying prior to the restoration of St. Michael defeating Evil painting by Mattia Preti
No full textIn this study, a multimethodological analysis involving optical and physical/chemical diagnostic techniques and 3D photogrammetric survey was successfully applied, for the first time, on the large oil on canvas St. Michael defeating Evil painting by Mattia Preti, located inside the Church of the Immaculate Conception of Sarria (Floriana) in Malta. Pigmenting agents, binder media, and raw materials were first characterized, both at elemental and molecular scales, through X-ray fluorescence spectroscopy (XRF), optical stereo microscopy (SM), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX), Fourier transform infrared spectroscopy (FT-IR), and gas chromatography coupled with mass spectrometry (GC-MS). The main goal was to properly identify the execution technique of this famous painter, the artist’s palette, and possible nondocumented interventions. The 3D photogrammetric survey, on the other side, allowed us to noninvasively evaluate the extension of the areas that experienced restorations, and to properly map the domains of the different canvasses observed. The joints between canvasses suggested that the painting was folded and rolled up. In addition, the employment of a thermal camera gave evidence of the different consolidating material injection points used during the restoration to strengthen the painting. The obtained results offer useful information for the development of optimized restoration and conservation strategies to be applied and provide, at the same time, answers to open questions related to provenance and dating of the investigated artwork
Development of a New Analytical Method for the Characterization and Quantification of the Organic and Inorganic Carbonaceous Fractions in Snow Samples Using TOC and TOT Analysis
No full textDifferent Light-Absorbing Snow Impurities (LASI) can deposit on snow- and ice-covered surfaces. These particles are able to decrease snow and ice albedo and trigger positive albedo feedback. The aim of this work was to develop a new method to quantify the carbonaceous fractions that are present in snow and ice samples that contribute significantly to their darkening. Currently, in the literature, there is an absence of a unified and accepted method to perform these studies. To set up the method proposed here, snow samples were collected at two Italian locations, Claviere and Val di Pejo (Northern Italy). The samples were analyzed using two main techniques, Total Organic Carbon analysis (TOC analysis) and Thermal Optical analysis in Transmittance mode (TOT), which enabled the speciation of the carbonaceous fraction into organic (OC), inorganic (IC), and elemental carbon (EC), and further into the soluble and insoluble parts. The results highlighted a correlation between the nature of the sample (i.e., location, age, and exposure of the snow) and the experimental results, giving validity to the method. For example, the abundant presence of terrigenous constituents was reflected in high amounts of insoluble IC. Moreover, due to the trend between insoluble IC and Elemental Carbon (EC), the role of IC in TOT analysis was investigated. Indeed, IC turned out to be an interfering agent, suggesting that the two techniques (TOC analysis and TOT) are complementary and therefore need to be used in parallel when performing these studies. Finally, the results obtained indicate that the newly proposed method is suitable for studying the carbonaceous fractions in snow samples
A New Laboratory Scale Methodology to Test Portable Air Cleaner (PAC) Devices: Optimization and Application
No full textGiven that people spend on average more than 80% of their time indoors, monitoring indoor air quality (IAQ) is of the utmost importance for the safeguard of human health. Indeed, due to penetration from outdoors and the presence of specific indoor sources, poor IAQ is not uncommon. The use of portable air cleaners (PACs) is one of many options to improve IAQ. The market offers many products, but not all of them have reliable documentation on their effectiveness. Literature standard methods for testing PACs toward pollutants require extensive resources. In this work, we developed a new laboratory scale methodology based on a small, easy to use, economical batch system to test the efficiency of PACs. With this method, three commercial PACs were successfully tested for effectiveness toward volatile organic compounds (VOCs) and particulate matter (PM). The method proved successful, and the results highlighted the importance of conducting these tests, in addition to field investigations
Set-up of a protocol for the assessment of indoor air quality towards the protection of works of art.
No full textThe effects of time and environmental conditions are well-known to be an issue with respect to works of art and historical buildings. Indeed, materials exposed both to outdoor and indoor environments are naturally subject to degradation over time. However, the importance of developing new methods to address the degradation of culturally significant objects is expected to grow in the future due to environmental causes. Fading, darkening, yellowing, and turning colour are only some of the better-known chemical degradation processes – induced or catalysed by environmental conditions - that affect works of art and architecture.
Moreover, complex and multi-layered artistic works such as paintings, frescos and wooden carvings, which are made of a mixture of organic and inorganic substances, interact both with each other and the surrounding environment.
In this research, the microclimatic conditions (temperature, relative humidity, and illuminance) and some air quality parameters such as particulate matter (PM) and pollutants (NO2 and BTEX) inside the Santuario della Beata Vergine dei Miracoli in Saronno (VA) were evaluated and monitored; this had the main purpose of determining whether the environmental requirements with regard to the health of the visitors and the conservation of the works of art present inside the building were adequate.
In fact, in the interior part of this historical building a beautiful fresco cycle painted by one of the masters of the Renaissance, Bernardino Luini, is displayed together with other important and valuable frescoes, paintings and wooden statues.
For this reason, dataloggers for temperature, relative humidity, and illuminance measurements, an optical particle counter (OPC) for PM determination and some diffusive passive samplers to quantify NO2 and BTEX concentrations were employed. The monitoring was performed at different locations in the Sanctuary, and lasted for several months, including important religious events like Easter Week. Furthermore, the outdoor parameters were evaluated and compared with the indoor ones to find possible correlations.
Also, the characterisation of the colour palette and products of degradation on one the Luini frescoes was carried out through several non-invasive and portable spectroscopic and imaging techniques like hyperspectral imaging, Raman, FTIR and XRF spectroscopies, and colourimetry, with the main purpose of discovering the conservation state of the artwork and possible relationships between the products from degradation and the pollutants in the indoor environment
Identification of natural dyes in historical tapestries, a LC-MS/MS approach
No full textThe present study concerns the identification of the colouring matter in ancient tapestries of different historical periods. The investigation was performed using HPLC-DAD-ESI-MS and the results were compared with a previously created reference database. Furthermore, the characteristic fragmentation pathway provided additional information for the identification of the dyes employed
Living Sensors based on Sansevieria Cylindrica for Microclimate Monitoring in the Santuario della Beata Vergine dei Miracoli
No full textIndoor air quality and microclimatic conditions contribute to the degradation of the works of art [1]. Limits for air quality parameters and physical quantities of interest for microclimate, in order to assure the longest conservation of the works in time, have been widely suggested for museums [2]. In particular, temperature, humidity, illuminance, particulate matter and gaseous pollutants concentrations arouse interest in the context of the monitoring. The study here presented aimed at monitoring ambient conditions through the adoption of innovative green and mimetic sensors based on plants, in the Santuario della Beata Vergine dei Miracoli [3]. This sanctuary was built between the 15th e 17th centuries, following a miraculous event, in Saronno, a small town of northern Italy. It hosts works of art from some of the most renowed and influential artists of the time. Bernardo Luini decorated the apse and presbytery of the church with some masterpieces such as the Marriage of the Virgin, while the dome was entirely frescoed by Gaudenzio Ferrari. The sculptor Andrea da Corbetta carved the marvelous Deposition and Last Supper. Following the nature of the place, it is not easy to keep ambient conditions under control and to perform measurements, considering the large number of people involved in the sanctuary. Keeping in mind the importance that the visual impact of the ambient has on the worshipers, classical measurement systems cannot be adopted for monitoring the area. The developed device regards a living sensor based on Sansevieria cylindrica plant for measurements of radiations, both visible and UVA, which could affect paintings inside the sanctuary, thus they represent important parameters to be considered for preventive conservation of cultural heritage. The working principle of the sensor is based on the metabolic processes of plants and the activity of soil micro-organisms [4-5]. This solution goes beyond “classical” approaches such as microelectronic devices and silicon devices, having several advantages: low cost, biodegradable, eco-friendly, nontoxic and capable to reduce the CO2 during the working phase by using photosynthesis processes. It is worth noting that this family of devices is able to operate without the adoption of batteries, by using its self-generating transduction property, and it is also mimetic. Thanks to this latter characteristic, the device is capable to avoid any form of visual pollution and, for this reason, the proposed solution is suitable for indoor and outdoor applications of historical and artistic interest. It is worth noting that several sensors have been applied, since October 2022, in the Santuario della Beata Vergine dei Miracoli with the aim to monitor the level of radiation with the objective to ensure that its value does not cause damage to the work of art in accordance with the legislation
Experimental study on the catalytic action of heavy metals in the sulphation process and formation of black crusts by accelerated ageing tests
No full textResearch conducted on the degradation of cultural and architectural heritage caused by the deposition of air pollutants indicates that the deterioration of carbonate materials is due primarily to the interaction of the substrate with sulphur dioxide (SO2) and particulate matter (PM) deriving from the combustion of fossil fuels.
The main chemical degradation process is the sulphation of the substrate, which consists in the initial conversion of SO2 into sulphuric acid (H2SO4) and the subsequent reaction of this product with calcium carbonate (CaCO3).
This leads to the formation of black crusts composed mainly of gypsum (CaSO4⋅2 H2O), inside which PM is embedded. These carbonaceous particles also contain heavy metals that can act as catalysts in both stages of the sulphation process, favouring the degradation of the substrate. However, the degree to which each specific metal is able to affect sulphation is still unclear. This research aims to evaluate which heavy metals activate the sulphation process by carrying out targeted exposure mock-up tests in special climatic chambers. The selected cations were the following: Fe3+, Cu2+, Mn2+, Pb2+, Cr3+, V5+ (deposited concentrations were calculated based on data from urban PM). In addition, mixtures involving three or more metal cations were also used to evaluate possible synergistic effects. Finally, PM2.5 extracted from quartz-fibre filters sampled in the city of Milan was also included in the experimentation. The physicochemical characterization of the different mock-up samples was performed both in the pre-exposure and post-exposure phases using different analytical techniques such as: colorimetric analysis, stereomicroscopic observations, SEM-EDX (Scanning Electron Microscopy coupled to Energy Dispersive X-Ray Spectroscopy), IC (Ion Chromatography), and XRPD (X-ray powder diffraction). Results show that some metal cations (Pb, Cu, Cr) are able to activate the catalytic process faster than others (Fe, Mn).
Also, samples treated with metal mixtures and PM2.5 exhibited the greatest catalytic action, highlighting a synergistic effect of more heavy metals acting together
The Loss of Symmetry in Unilateral Bony Syngnathia: Case Report and Literature Review
No full textCongenital syngnathia is a very rare condition of unknown etiology with multiple clinical manifestations due to different combinations of bony or soft tissue adhesions between the mandible and maxilla. It shares possible association with other congenital anomalies in the head and neck region, or with other syndromes. The aims of the present work were: (1) to perform a literature review on bony syngnathia in order to obtain a general framework on epidemiology and management protocol; (2) to describe a case of a two-year-old boy with a left unilateral bony fusion treated with a distraction protocol of three months. Original articles were searched through PubMed, Cochrane Central database and Embase with a cut-off date of June 2022. In total, 94 articles were identified through database searching. After 39 exclusions, 55 articles were included in the review process. Eighty-seven cases of bony syngnathia have been reported from 1936 to 2022, and different classifications have been suggested in terms of location, extension, functional outcomes and management protocol. Complications may range from feeding difficulty to aspiration pneumonia and respiratory arrest. Early surgery is generally required to release the ankylosis and to establish good mandible function
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