26 research outputs found

    Monitoring and preservation of stone cultural heritage using a fuzzy model for predicting salt crystallisation damage

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    In this study, a fuzzy model is presented for predicting the possibility of degradation due to salt crystallisation cycles. The formalization of the proposed model has been based on the multivariable approach which considers environmental data (such as temperature, solar radiation, wind speed, rain quantity, relative humidity), characteristic inflection points of specific salts and stone features derived from laboratory characterizations (including mechanical properties, porosity, and mineralogical composition). Modeling results have been compared with experimental data elaborations acquired by monitoring a semi-confined archaeological site situated in the city of Cagliari (Munatius Irenaus cubicle), revealing substantial alignment in the degradation kinetics trends. Moreover, the achieved outcomes show the remarkable capability to identify salt crystallisation phenomenon type (efflorescence or subflorescence)

    Salt Crystallization in Limestone: Materials Decay and Chemomechanical Approach

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    Salt crystallization is a particularly relevant issue in the conservation of limestones used in Cultural Heritage sites. In this study, various facies of limestones were characterized through porosimetric and mechanical tests. The samples were subjected to experiments to determine their resistance to salt crystallization by verifying the number of cycles at which 50% of them began to lose weight. This number of experimental cycles was compared with the result calculated by the analytical procedure of a chemomechanical model found in the literature. The comparison showed a significant capability of the model to predict the experimental data

    A fuzzy model for studying kinetic decay phenomena in Genna Maria Nuraghe: Material properties, environmental data, accelerated ageing, and model calculations

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    In this study, a fuzzy model has been proposed for the control of the degradation process in Cultural Heritage. Specifically, the focus has been on the Nuragic building, Genna Maria, in Villanovaforru, Sardinia. Environmental data and material properties were considered to formalize inferences between different variables of the model. The results highlight the possibility of significant decay processes, such as salt crystallization and freeze-thaw cycles, estimated for all months of the year. A comparison between model elaborations and experimental data (material characterization, environmental data, accelerated ageing) demonstrates the reliability of the proposed procedure

    An Updated Review: Opuntia ficus indica (OFI) Chemistry and Its Diverse Applications

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    The beneficial nutrients and biologically active ingredients extracted from plants have received great attention in the prevention and treatment of several diseases, including hypercholesterolemic, cancer, diabetes, cardiovascular disorders, hypoglycemic, hypolipidemic, edema, joint pain, weight control, eye vision problems, neuroprotective effects, and asthma. Highly active ingredients predominantly exist in fruit and cladodes, known as phytochemicals (rich contents of minerals, betalains, carbohydrates, vitamins, antioxidants, polyphenols, and taurine), which are renowned for their beneficial properties in relation to human health. Polyphenols are widely present in plants and have demonstrated pharmacological ability through their antimicrobial, anti-inflammatory, anti-bacterial, and antioxidant capacity, and the multi-role act of Opuntia ficus indica makes it suitable for current and future usage in cosmetics for moisturizing, skin improvement, and wound care, as healthful food for essential amino acids, as macro and micro elements for body growth, in building materials as an eco-friendly and sustainable material, as a bio-composite, and as an insulator. However, a more comprehensive understanding and extensive research on the diverse array of phytochemical properties of cactus pear are needed. This review therefore aims to gather and discuss the existing literature on the chemical composition and potential applications of cactus pear extracts, as well as highlight promising directions for future research on this valuable plant

    Coating's influence on wind erosion of porous stones used in the Cultural Heritage of Southern Italy: Surface characterisation and resistance

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    Wind erosion (or aeolian corrosion) is one of the most relevant causes of weathering and degradation which has affected building surfaces in Cultural Heritage. The effect depends on the wind strength, the impact of particles transported and their size and the characteristics of surfaces affected. This aspect is very important for historical buildings constructed by using limestone as Lecce stone (LS). LS has an extraordinary ability to be shaped, but is very sensitive to decay. Exfoliation, wind erosion, absorption of water by capillary from the soil, are its main degradation causes. For such a reason, the application of effective products able to act as “sacrifice film” became necessary in order to minimise the degradation rate by preserving the limestone substrate against serious weathering agents. In this work, the effects of aeolian corrosion, simulated by means the accelerated test with sandblasting method, were studied. In particular, the effectiveness of two specific commercial coatings, such as an innovative free-solvent hybrid organic-inorganic coating (HYBRID) and a solvent-based coating (AS), was assessed relating to their capability to preserve Lecce stone from the aeolian corrosion phenomenon. The protective efficacy was guaranteed by both the commercial coatings even after accelerated wind erosion test, by confirming a high hydrophobicity, low capillary water absorption and an adequate depth of penetration inside the stone able to assure durability

    Degradation phenomena of Templo Pintado painted plasters

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    Weathering processes of Templo Pintado (Painted Temple) caused by environmental and climatic agents have been investigated in this work. The temple is part of the archaeological complex of Pachacamac, situated in a desert area of Western Peru characterized by high relative humidity, temperature, relevant winds, and remarkable solar radiation. These atmospheric conditions result in wet-dry cycles and wind erosion, eventually inducing pulverization, exfoliation, and detachment in plaster and painted surfaces. The seasonal variation of atmospheric conditions was monitored on a daily basis for five years, revealing that the seasonal cycles exhibit great similarity. Experimental results show a linear correlation between loss of material and environmental temperature. In particular, degradation increases with temperature rises. Moreover, high temperatures are combined with stronger winds and drying of materials (wet-dry cycles), which contribute to accelerating degradation kinetics

    Evaluation of antibody response to BNT162b2 mRNA COVID-19 vaccine in patients affected by immune-mediated inflammatory diseases up to 5 months after vaccination

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    SARS-CoV-2 vaccination with mRNA product BNT162b2 elicited high immunogenicity in healthy subjects in trials. This study aims to better understand the factors that influence the humoral immune response to vaccination against SARS-CoV-2 in patients with immune-mediated inflammatory diseases (IMIDs). We enrolled patients and healthy healthcare workers control group (HCW) that underwent mRNA BNT162b2 vaccination and measured the serum IgG anti-S-RBD response at booster dose (T1), one month after booster dose (T2) and up to 5 months (T3). Demographic, disease-specific and vaccination data were recorded. Vaccination response of 551 participants naĂŻve to SARS-CoV-2 infection were included in HCW and 102 in the IMID group, analyzing separately those on anti-CD20. At T2 all naĂŻve HCW developed anti-S-RBD-IgG, while 94% of IMID responded (p < 0.001). IMID patients had a significantly different level of IgG than HCW at both T1 (p = 0.031), T2 (p < 0.001), while there was no significant difference at T3. There were no statistically significant differences according to the IMID type or to ongoing treatment with immunosuppressants, corticosteroids or biological drugs other than anti-CD20. The proportion and magnitude of response was significantly lower in IMID treated with anti-CD20 drugs. There was a correlation with age at T1 and at T2 but not at T3, stronger in patients than in HCW. Immune response close after BNT162b2 vaccination is reduced in patients with IMID, but there is no significant difference at 5 months. The measured reduction is related to age and the disease itself rather than treatments, with the exception of anti-CD20 drugs

    Surveillance of Summer Mortality and Preparedness to Reduce the Health Impact of Heat Waves in Italy

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    Since 2004, the Italian Department for Civil Protection and the Ministry of Health have implemented a national program for the prevention of heat-health effects during summer, which to-date includes 34 major cities and 93% of the residents aged 65 years and over. The Italian program represents an important example of an integrated approach to prevent the impact of heat on health, comprising Heat Health Watch Warning Systems, a mortality surveillance system and prevention activities targeted to susceptible subgroups. City-specific warning systems are based on the relationship between temperature and mortality and serve as basis for the modulation of prevention measures. Local prevention activities, based on the guidelines defined by the Ministry of Health, are constructed around the infrastructures and services available. A key component of the prevention program is the identification of susceptible individuals and the active surveillance by General Practitioners, medical personnel and social workers. The mortality surveillance system enables the timely estimation of the impact of heat, and heat waves, on mortality during summer as well as to the evaluation of warning systems and prevention programs. Considering future predictions of climate change, the implementation of effective prevention programs, targeted to high risk subjects, become a priority in the public health agenda

    ECMO for COVID-19 patients in Europe and Israel

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    Since March 15th, 2020, 177 centres from Europe and Israel have joined the study, routinely reporting on the ECMO support they provide to COVID-19 patients. The mean annual number of cases treated with ECMO in the participating centres before the pandemic (2019) was 55. The number of COVID-19 patients has increased rapidly each week reaching 1531 treated patients as of September 14th. The greatest number of cases has been reported from France (n = 385), UK (n = 193), Germany (n = 176), Spain (n = 166), and Italy (n = 136) .The mean age of treated patients was 52.6 years (range 16–80), 79% were male. The ECMO configuration used was VV in 91% of cases, VA in 5% and other in 4%. The mean PaO2 before ECMO implantation was 65 mmHg. The mean duration of ECMO support thus far has been 18 days and the mean ICU length of stay of these patients was 33 days. As of the 14th September, overall 841 patients have been weaned from ECMO support, 601 died during ECMO support, 71 died after withdrawal of ECMO, 79 are still receiving ECMO support and for 10 patients status n.a. . Our preliminary data suggest that patients placed on ECMO with severe refractory respiratory or cardiac failure secondary to COVID-19 have a reasonable (55%) chance of survival. Further extensive data analysis is expected to provide invaluable information on the demographics, severity of illness, indications and different ECMO management strategies in these patients

    Thermal conductivity of porous building materials: An exploration of new challenges in fractal modelling solutions

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    The improvement in the insulation material performance is one of the recent crucial problems. The energy consumption in the construction and buildings field has a significant impact on the society and the environment. For these reasons, researchers have focused on studying their thermal behaviour in order to improve fabrication methods and material design structures. In this sense, a great contribution has been offered by the modeling procedures. A remarkable attention has been dedicated to the application of fractal geometry which seems to be a promising method to replicate the porous structures as well as to predict the effective thermal conductivity. In this paper, a review of different modeling procedures is presented, comparing both traditional and fractal theory-based approaches. Fractal models demonstrate high reliability in reproducing experimental data under various conditions, including dry and moist systems. This is further enhanced by the application of recursive formulas, which streamline calculations even for complex porous microstructures. The choice between one model and another depends on the specific characteristics of the materials under study. In all cases, the versatility of the analytical procedures enables one to achieve a remarkable agreement with experimental data
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