120 research outputs found

    Archaeometric Study of the White Marbles from “Madonna Della Febbre” Altar in San Domenico Church (Cosenza, Southern Italy)

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    San Domenico Church was built between 1441 and 1468 and represents one of the most important historical buildings of the Cosenza area (Calabria, Southern Italy) thanks to its architectonic style and the works inside, such as the “Madonna della Febbre”, a notable marble altar dated back to the XVI century. The church, as well as the sculptural group, underwent various interventions over time, unfortunately scarcely documented; thus, in this paper, the characterization of six white marble samples coming from the altar, was carried out to determine their provenance. The samples were analyzed by means of complementary methodologies well known in the archaeometric field: polarized optical microscopy (POM); an electron probe micro analyzer coupled with an energy dispersive spectrometer (EPMA-EDS); inductively coupled plasma–mass spectrometry (ICP-MS); and isotope ratio mass spectrometry (IRMS). The results provided important information about the “Madonna della Febbre” altar, suggesting the presence of different typologies of marbles and hypothesizing their possible provenance, including Carrara and Docimium. It was not clear if these marbles were re-used materials but, regardless, the reported information adds precious elements to the history of the entire architectonic complex, providing new issues to be deepened

    The methodology of investigation on red- and black-figured pottery of unknown provenance

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    This contribution is concerned with the archaeometric study of seven red- and black-figured potteries, kindly provided by the Carabinieri Corps for Protection of Cultural Heritage, Cosenza Unit (Calabria, Italy). The study was aimed to establish the authenticity of the archaeological artifacts and for this purpose an analytical approach, based on mineropetrographic and geochemical investigations, was applied. Petrographic analysis (OM), scanning electron microscopy (SEM) coupled with EDS microanalysis and X-ray diffraction (XRD) studies were carried out with the aim of identifying technological features, microstructure and to obtain information on the technological features of each sample. Finally, Fourier transform infrared spectroscopy (FT-IR) was used to detect possible surface coatings

    Study of the effects of salt crystallisation on degradation of limestone rocks

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    Salt crystallization is widely recognized as a cause of deterioration of porous building materials. In particular, the crystallization pressure of salt crystals growing in confined pores is found to be the main cause for damage. The aim of this study is to better understand the degradation of porous rocks induced by salt crystallisation and correlate such processes with the intrinsic characteristics of materials. With this intend, an experimental salt weathering simulation has been carried out on two limestones widely used in the Baroque architecture of eastern Sicily. A systematic approach including petrographic, porosimetric and colorimetric analyses, was used to evaluate the correlation among salt crystallisation, microstructural and chromatic variations of limestone. Results showed a quite different resistance of the two limestones to salt damage, and this was found to be strongly dependent on their pore structure and textural characteristics

    Comparative study of protective coatings for the conservation of Urban Art

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    Contemporary mural paintings are complex artworks for several reasons, including the heterogeneity of the materials used to make them, and the different types of substrate on which the painting layers can be applied. Currently we are focused on a technical-scientific research aimed to solve the issues related to the long-term care and maintenance of murals, by evaluating the performance of several protective coatings applied on these artworks. This paper deals with a preliminary experimentation aimed to: (a) study the interaction of antigraffiti products on common synthetic paints; (b) test the effectiveness and efficiency of several commercial products used as antigraffiti; (c) define of the best procedure to remove vandalism spray from a coated surface, without damaging the underlying painting layers. Tests have been carried out on laboratory specimens and the performances of different antigraffiti agents have been evaluated by optical and electron microscope observations, as well as by colorimetric measurements

    Experimental analysis of a CO2 heat pump for instantaneous domestic hot water production

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    Abstract The performance of a CO2 (R744) heat pump (HP) depends strongly on the application and on the environmental operating conditions. In particular, the CO2 HP becomes competitive compared to traditional heat pumps using halogenated refrigerants in applications characterized by a high hot water demand (hospitals, sport centres, etc.). This paper deals with the experimental analysis of an air-to-water commercial R744 HP tested in ENEA laboratories for instantaneous production of domestic hot water (DHW). The results show that HP efficiency is strongly affected by the inlet water temperature at the gas cooler. A test equipment capable of maintaining the ambient temperature at a desired value (between -10 °C and +20 °C), and managing water flow and water temperature (between 15 °C and 45 °C) is used to evaluate the machine COP as a function of the boundary conditions (inlet gas cooler water temperature, water flow rate, external ambient temperature). The analysis shows the considerable potential of R744 heat pumps for the instantaneous production of DHW, combining a high performance and relevant energy saving. As well, it points out that, to maximize the COP it is necessary to combine the HP with a high stratification storage system, which ensures a suited inlet water temperature, and with a correct value of water flow

    New insights to assess the consolidation of stone materials used in built heritage: the case study of ancient graffiti (Tituli Picti) in the archaeological site of Pompeii

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    Tituli Picti are an ancient form of urban graffiti very common in the archaeological site of Pompeii (Naples, South—Italy). They are generally made of red pigments applied on walls of Campanian ignimbrite. This paper deals with a scientific investigation aimed to their conservation. This is a challenging task since it requires a multidisciplinary approach that includes restorers, archaeologists and conservation scientists. The study has provided suggestions on the proper way to conserve Tituli Picti over time. In the present work, several specimens of Campanian ignimbrite were painted with red earth pigment; lime and Arabic gum have been used as binders as well. Such painted stones were treated with three consolidants: a suspension of reactive nanoparticles of silica, ethyl silicate and an acrylic microemulsion. Treated and untreated specimens were subjected to thermal aging, artificial solar radiation and induced crystallization decay. It has been assessed the colorimetric variations induced by treatments. Moreover, the micromorphologic features of the consolidated surfaces have been highlighted by means of electron microscope observations. The scotch tape test allowed to compare the superficial cohesion induced by the three used products. According to the results, ethyl silicate seems to represent the most successful product

    Polyphenols and ischemic stroke: Insight into one of the best strategies for prevention and treatment

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    Ischemic stroke (IS) is still among the leading causes of death and disability worldwide. The pathogenic mechanisms beyond its development are several and are complex and this is the main reason why a functional therapy is still missed. The beneficial effects of natural compounds against cardiovascular diseases and IS have been investigated for a long time. In this article, we reviewed the association between the most studied polyphenols and stroke protection in terms of prevention, effect on acute phase, and rehabilitation. We described experimental and epidemiological studies reporting the role of flavonols, phenolic acid, and stilbens on ischemic mechanisms leading to stroke. We analyzed the principal animal models used to evaluate the impact of these micronutrients to cerebral blood flow and to molecular pathways involved in oxidative stress and inflammation modulation, such as sirtuins. We reported the most significant clinical trials demonstrated as the persistent use of polyphenols is clinically relevant in terms of the reduction of vascular risk factors for IS, such as Atrial Fibrillation. Interestingly, different kinds of polyphenols provide brain protection by activating different pathways and mechanisms, like inducing antithrombotic effect, such as Honokiol. For this reason, we discussed an appropriate integrative use of them as a possible therapeutic alternative against stroke

    Lp-PLA 2 , a new biomarker of vascular disorders in metabolic diseases

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    Metabolic diseases are chronic disorders correlated to a greater risk of cardiovascular event and death. Recently, many data have sustained the biological link between microvascular dysfunction, oxidative stress, vascular inflammation, and metabolic diseases. The determination of new and specific blood biomarkers of vascular inflammation associated with obesity-related metabolic syndrome (MetS) and diabetes such as lipoprotein-associated phospholipase A 2 (Lp-PLA 2 ) could be useful to identify subject with high risk of cardiovascular events. Lp-PLA 2 participates by a crucial role in microvascular dysfunction and oxidative stress showing positive association with metabolic disorders. In this review, we will argue the evolving role of Lp-PLA 2 in predicting cardiovascular events in metabolic disease patients

    Free-amino acid metabolic profiling of visceral adipose tissue from obese subjects

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    Interest in adipose tissue pathophysiology and biochemistry have expanded considerably in the past two decades due to the ever increasing and alarming rates of global obesity and its critical outcome defined as metabolic syndrome (MS). This obesity-linked systemic dysfunction generates high risk factors of developing perilous diseases like type 2 diabetes, cardiovascular disease or cancer. Amino acids could play a crucial role in the pathophysiology of the MS onset. Focus of this study was to fully characterize amino acids metabolome modulations in visceral adipose tissues (VAT) from three adult cohorts: (i) obese patients (BMI 43-48) with metabolic syndrome (PO), (ii) obese subjects metabolically well (O), and (iii) non obese individuals (H). 128 metabolites identified as 20 protein amino acids, 85 related compounds and 13 dipeptides were measured by ultrahigh performance liquid chromatography-tandem mass spectroscopy (UPLC-MS/MS) and gas chromatography-/mass spectrometry GC/MS, in visceral fat samples from a total of 53 patients. Our analysis indicates a probable enhanced BCAA (leucine, isoleucine, valine) degradation in both VAT from O and PO subjects, while levels of their oxidation products are increased. Also PO and O VAT samples were characterized by: elevated levels of kynurenine, a catabolic product of tryptophan and precursor of diabetogenic substances, a significant increase of cysteine sulfinic acid levels, a decrease of 1-methylhistidine, and an up regulating trend of 3-methylhistidine levels. We hope this profiling can aid in novel clinical strategies development against the progression from obesity to metabolic syndrome
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