0000000000008103
AUTHOR
Giovanni Rizzo
Intervento di restauro conservativo di un dipinto murale staccato, raffigurante la "Presentazione della Vergine al tempio", attribuito alla scuola del Novelli
The role of cork powder as a compatibilizing filler of synthetic materials used to putty shrinkage cracks of wood
Frammenti di mosaico riportati su calcestruzzo:le interazioni con il supporto e il progetto di conservazione
Caratterizzazione delle vernici utilizzate nella liuteria storica
LARGE DEFORMATION CREEP BEHAVIOR OF A SOLID POLYMER.
Abstract The effect of loading rate and strain on the creep behavior after sample yielding has been studied in previous communications (14–15) for Mylar in tension and for Lexan in compression. In this work the creep behavior of Lexan samples previously elongated is considered both in tension and in compression. A procedure which collects all the data independently of both loading rate and initial creep strain is proposed.
Characterization of varnishes used in the ancient musical instruments
The anisotropic behaviour of a preoriented poly (ethylene terephthalate) during plastic deformations
Data on the anisotropic tensile behavior of samples cut along several directions of a biaxially oriented PET sheet are here presented. Shear deformations were observed together with the usual elongations. The data are compared with the predictions of a non-linear model recently proposed.
I materiali lapidei naturali ed artificiali della Fontana Pretoria di Palermo
A specific operative protocol set up during the restoration of the Grammichele's slate slab
Floor and wall mortars of archaeological site of Selinunte , Sicily
Necking behavior of low-density polyethylene-isotactic polypropylene blends: A morphological investigation
The tensile behavior of low-density polyethylene-isotactic polypropylene blends was investigated at room temperature. Neck formation and propagation along the whole length of the samples were observed for the whole range of composition. This behavior, which is not indicated by most data available in the literature, was examined in relation to sample morphology by scanning electron microscopy. The results of this investigation indicated some differences between the morphology of these materials and the morphology of blends which do not undergo necking propagation.
Il Teatro Greco -Romano di Taormina
The "Fossa della Garofala" in Palermo: a geological site rich in cultural heritage
The Fossa della Garofala is a short, narrow valley, enclosed by sub-vertical banks, which was carved out by the Kemonia creek on the calcarenitic table that makes up the bedrock of the Plain of Palermo. It forms the outermost hem of the Conca d’Oro landscape where, set in an urban area, geologic and geomorphologic features of value join historical cultural values dating from the Punic period to the XIX century. This combination places the entire area in one of the most significant, albeit little known, pages of history: the history of traditional suburban landscape. This rare synthesis of natural and anthropic landscapes offers the opportunity to create theme itineraries of great cultural a…
Minimo Intervento per la Conservazione di un Dipinto su Tavola
Petrography and decay of a marly limestone in the cloister of a medieval cathedral in Sicily
This paper deals with a significant process of decohesion of a marly limestone, taking place in the cloister of the medieval Cathedral of Cefalu, a pleasant town on the northern coast of Sicily. After desalination with deionised water and consolidation with ethyl silicate, the decay of the stone became faster. The aim of our study is to characterise the stony material and investigate the observed decay phenomena. The stone, that is a poor building material indeed, is characterised by means of petrographical, chemical and physical analyses on samples taken from the monument. Furthermore, experimental tests are performed in the laboratory in order to highlight the causes of incompatibility be…
THE SCENOGRAPHY OF SERPOTTA STUCCOES REVISITED - MATERIAL AND FORM
The material that lies beneath the smooth shining surface of the stuccoes of the Serpotta family who used to work in Sicily from 1670 to 1730, has been thoroughly studied in previous papers, disclosing the deep, albeit empirical, knowledge of materials science that guided the artists in creating their masterpieces. In this work, attention is focused on the solid perspective and on the scenographic sculpture by Giacomo Serpotta, who is acknowledged as the leading exponent of the School. The study deals with some particular works of the artist, the “small-scaled plastic theatres”, so-called “teatrini”, which he made for the San Lorenzo Oratory in Palermo. On the basis of archival documents an…
DNA Hypomethylation and Histone Variant macroH2A1 Synergistically Attenuate Chemotherapy-Induced Senescence to Promote Hepatocellular Carcinoma Progression
Abstract Aging is a major risk factor for progression of liver diseases to hepatocellular carcinoma (HCC). Cellular senescence contributes to age-related tissue dysfunction, but the epigenetic basis underlying drug-induced senescence remains unclear. macroH2A1, a variant of histone H2A, is a marker of senescence-associated heterochromatic foci that synergizes with DNA methylation to silence tumor-suppressor genes in human fibroblasts. In this study, we investigated the relationship between macroH2A1 splice variants, macroH2A1.1 and macroH2A1.2, and liver carcinogenesis. We found that protein levels of both macroH2A1 isoforms were increased in the livers of very elderly rodents and humans, a…
Effetti fotodegradativi sui manufatti lignei impregnati con materiali polimerici
Agents Displacement in Arbitrary Geometrical Spaces: An Evolutionary Computation based Approach
In many different social contexts, communication allows a collective intelligence to emerge. However, a correct way of exchanging information usually requires determined topological configurations of the agents involved in the process. Such a configuration should take into account several parameters, e.g. agents positioning, their proximity and time efficiency of communication. Our aim is to present an algorithm, based on evolutionary programming, which optimizes agents placement on arbitrarily shaped areas. In order to show its ability to deal with arbitrary bi-dimensional topologies, this algorithm has been tested on a set of differently shaped areas that present concavities, convexities …
Valutazione dell'efficacia del consolidamento attraverso prove meccaniche
Deformation recovery behavior of a solid polymer after tensile yielding
In this work the deformation recovery behavior of an amorphous polymer after large tensile deformation is studied at different temperatures. The effect of three parameters other than temperature has been pointed out in previous works (1–3).
A specific operative protocol set up during the restoration of the Grammichele slate slab
This work deals with the conservation of a slate slab, representing the map of Grammichele, a small town in the hinterland of South Eastern Sicily. The slab was engraved and painted in 1693, just after the tremendous earthquake that distroyed most of the towns in that area. The conservation process is illustrated through three steps: i) archive research; ii) physical chemical analysis of constitutive materials and degradation products; iii) planning and carrying out of the restoration and conservation operations.
Mortars and Plasters under the Mosaics and the Wall Paintings of the Roman Villa at Piazza Armerina, Sicily
The Roman Villa at Piazza Armerina in Sicily, built in many successive steps over the 2nd and 3rd centuries A.D., is renowned all over the world for both the wealth and the refinement of its mosaic floors. In February 2007 the Regional Government of Sicily started a restoration project of the whole archaeological site. The systematic survey and study of all decorative elements highlighted the value of wall paintings, which until then were almost unknown except for casual approaches to specific problems of conservation, carried on without any relation to the far and away famous mosaics. This paper shows the results of a physical chemical investigation of the mortars used for both floors and …
Problems of soil and groundwater pollution in the disposal of “marble” slurries in NW Sicily
This work deals with disposal of slurries generated during the cutting and polishing processes of slabs of decorative sedimentary carbonate rocks in the north western Sicily. At present, they are used as fillers of dismantled quarries near the sawmills and, as a final step of reclamation, are covered with earth layers. In spite of such inexpensive solution, there is lack of knowledge about the composition of the waste. In order to assess if there is any threat for the environment and to suggest indications for alternative solutions, such as recycling or inactivation processes, the slurries were analysed by XR diffraction, simultaneous thermal analysis, ICP/MS, ionic chromatography, FTIR, UV…
Experimental study of stress-relaxation behaviour of polycarbonate after yielding
The viscoelastic behaviour of a bisphenol A polycarbonate after yielding is described by means of empirical superposition of coordinates along both time and stress axis, which allow collecting stress relaxation data, taken both in tension and in compression, into a master curve.
Evaluation of Cement Content in Hardened Concrete
Can you feel it will you tell me. Encouraging sentiment expression on the web
In a recent trend in web communication, news outlets and blog platforms allow readers to express opinions about what they have read by choosing an associated feeling, or sentiment ex- pression. This emerging trend, fitting between liking and full text comments, has not still found the popularity it should. The thesis of this paper is that this is also due to the way the sen- timent choice is presented to the user. In order to test this hy- pothesis we have devised a pilot experiment; results confirm that a simpler way of choice increases sentiment expression and yields result that are more aligned with ground truth.
Note preliminari sulla caratterizzazione di alcuni materiali
Osservazioni sulla successione stratigrafica degli stucchi della scuola di Giacomo Serpotta a Palermo
Il consolidamento del legno di faggio mediante polimerizzazione frontale di monomeri acrilici
Characterization of hydraulic mortars from roman aqueducts of thermae (Sicily)
LA FONTANA PRETORIA IN PALERMO. Hic fons, cui similis nullus in orbe patet. Indagini chimico-petrografiche sui materiali lapidei e sul loro degrado
A specific operative protocol set up during the restoration of San Michele Arcangelo’s marble statue
Questo lavoro descrive le diverse fasi dell’intervento di conservazione di una statua di marmo del XVI secolo, raffigurante San Michele Arcangelo, custodita presso la Galleria Regionale di Palazzo Abatellis di Palermo. Inizialmente è stata effettuata un’indagine di archivio per inquadrare l’opera dal punto di vista storico artistico ed iconografico. Quindi sono stati effettuati: un rilievo grafico e digitale 3D, una mappatura di tutte le forme di degrado rilevate e dei segni di interventi precedenti, le analisi dei materiali costitutivi e dello stato di conservazione, mediante tecniche non distruttive o microdistruttive. Infine è stato progettato ed eseguito l’intervento di conservazione, a…
Effectiveness of Preservative Treatments on Coloured Ruditic Building Stones
: The dark grey Breccia di Billiemi and the Ammonitico Rosso of Piana degli Albanesi, two coloured stones widely used in monuments both outdoor and indoor in Sicily, undergo significant decay as effect of weathering: colour change and development of surface microcracks which affect not only the chromatic aspect but also the state of aggregation. In a previous study (Fracture and Failure of Natural Building Stones, 2006, Springer, Dordrecht, The Netherlands: 329), such effects were successfully reproduced on laboratory samples by means of artificial accelerated weathering and the different response of veins and grains to the ageing agents was related to the microstructure of stones. In this…
Studio dei materiali costitutivi e dei fenomeni di degrado del Grande Cretto
Il degrado degli stucchi serpottiano a Palermo in relazione alle condizioni ambientali di conservazione
This work is part of a demanding project, called “Progetto Serpotta”, performed since 2000 in cooperation with Soprintendenza Beni Culturali of Palermo. Aim of the project is the restoration of the unique stucco's artworks moulded by Giacomo Serpotta and his co-workers end of 17th -beginning of 18th century. This paper is focused on the problem of salt efflorescences, that are widely present in all of the churches and oratories restored in the framework of “Progetto Serpotta”. Particular attention is given to the relationship between the constitutive matter of the stuccoes, as analysed by means of both X ray diffractometry and optical microscopy, and the salts composition, as analysed by me…
A proposal for the preservation and use of the geosite and the cultural heritage of the "Fossa della Garofala" in Palermo
Giacomo Serpotta and the stuccoers of Palermo: aspects of materials used in refined decorative activity. The costitutive materials
Estudio comparativo de tratamientos de consolidaciòn. Aplicaciòn a rocas calcarenìticas y calizas
The paper deals with the effectiveness of different protective treatments on porous stones used in the architecture and monuments in Spain and Sicily.
I materiali lapidei naturali ed artificiali della Fontana Pretoria a Palermo
Floor and wall mortars of the archaeological site of Selinunte , Sicily
Characterization of stucco works by means of simultaneous thermal analysis
Problemi di Conservazione di un'opera di Land Art di straordinarie dimensioni: il Grande Cretto di Alberto Burri a Gibellina (TP)
This work deals with the conservation of one of the largest land art works in the world. It is a sort of white shroud laid on the ruins of the town of Gibellina, Sicily, after the tremendous earthquake of January 1968. The most significant aspects of the degradation phenomena observed on site are related to some faults in the construction, due to the prevailing of the artistic requirements over the good rules of concrete technology. Furthermore the guidelines for both a conservation intervention and the subsequent maintenance of the art work are also indicated.
The skill in materials selection and processing at the Serpotta's studio during the baroque period in Palermo
Calcestruzzi delle Aviorimesse per Idrovolanti di Pier Luigi Nervi a Marsala (1940-41). Composizione e Tessitura
Giacomo Serpotta and the stuccoers of Palermo: aspects of materials used in refined decorative activity. The processes of degradation
L'uso di cariche cellulosiche per migliorare la compatibilità col legno dei materiali polimerici utilizzati nella stuccatura delle fessure
Valutazione dello stato di conservazione dei materiali in relazione al grado di aggressività dell'ambiente nel quale sono posti in opera
Le aviorimesse di Pierluigi Nervi a Marsala: correlazioni tra le diverse modalità di esecuzione e lo stato di conservazione
This work deals with the composition and the state of conservation of the concrete of two hangars designed and built by Pier Luigi Nervi in 1940-1941. The interest in this project is related both to the use of on site prefabrication for so large structures (45x55 m plan) and to some peculiarities of the mix design, in particular the aggregate/binder ratio and the lithological composition of the aggregates. The study has been performed by means of X ray diffractometry, optical microscopy in trasmitted light on thin sections, ionic chromatography and carbonation tests. The twofold aim is to assess the conservation condition of concrete after 67 years of ageing in a marine spray environment an…
Physical behavior and morphology of biaxially rolled low-density polyethyleneX
Abstract Biaxial rolling was carried out on low-density polyethylene, and the rolled samples were studied using various techniques. Scanning electron microscopy and analysis of transport properties were used to obtain structural information, which was correlated to thermomechanical and dynamic-mechanical behavior. Results indicate that the initial morphology is destroyed by rolling and that clumps of molecules, like fibrils, are generated parallel to the rolling plane. The molecular orientation in the plane is mainly radial, with some reinforcement, particularly at high rolling degree, along axes diagonal with respect to the rolling directions. The rolling drastically reduces the molecular …
The recovery after bending of polycarbonate sheets
The recovery after bending has been extensively studied for metal sheets. The data presented in this work show that in the case of polymeric materials viscoelastic effects play a very important role. In particular the influence of deformation rate, the time the sample is held under load and the recovery time is analysed. A master curve is obtained by proper modification of a recent analysis developed for metal sheets.
Le calcareniti e le malte della Porta Nuova di Palermo
Master curves of viscoelastic behavior in the plastic region of a solid polymer
Stress relaxation and creep tests following strain ramps were made on Mylar, both above and below the yield stress. The ramp velocity was varied over a 40-fold range. All data exhibit nonlinear viscoelastic behavior. However, those obtained above the yield point, i.e., in the plastic region, could be reduced to single master curves for both the creep and the relaxation tests by means of a simple time shift factor. This factor is inversely proportional to the strain rate existing just prior to the test.
NATURAL AND ACCELERATED WEATHERING OF TWO COLOURED SICILIAN BUILDING STONES
The wall paintings of the Roman Villa at Piazza Armerina in Sicily
Analisi di vernici utilizzate nella liuteria storica
L'uso del Gesso nelle Costruzioni del Vallo di Mazara in Sicilia
Effect of cooling rate on the viscoelastic properties in the plastic zone of solid polymers
PMMA and PC samples were subjected to several cooling rates from the glass transition temperature.
Le specie legnose della Sala Martorana di Palazzo Comitini a Palermo.
Characterization of hydraulic mortars by means of simultaneous thermal analysis
The properties of hydraulic mortars were studied by means of simultaneous thermal analysis (STA), according to a procedure proposed in the literature. Hydraulic limes, cement and/or slaked lime were mixed using different proportions of both inert and reactive aggregates, in order to test the effectiveness of such procedure in distinguishing the different degree of hydraulicity of such samples. The use of the normalized coordinates suggested in the literature results in overlapping of the clusters of different kinds of mortars. Modified coordinates are proposed, which give promising results in view of outlining a 'master curve' of hydraulicity.
Le murature del Baglio e del Palazzo Filangeri Cutò di Villafrati (PA): studio chimico petrografico delle malte
DEGRADATION OF STUCCO WORKS OF SERPOTTA SCHOOL IN PALERMO AS RELATED TO THE CONSERVATION ENVIRONMENTAL CONDITIONS
La caratterizzazione delle malte dell'acquedotto Cornelio di Termini Imerese
Morphology and transport parameters of cold-rolled low-density polyethylene
Abstract Sheets of low-density polyethylene were rolled at room temperature. Samples with two different degrees of rolling were obtained. The structural changes induced by the rolling treatments were investigated using scanning electron microscopy and by analyzing the transport properties. Results suggest that in the analyzed range of deformation, the rolling induces a domain structure as a consequence of a nonhomogeneous distribution of the deformation. At lower local deformation the initial morphology is still present, while at higher deformation clumps of folded chains oriented along the rolling directions are observable. The transport properties indicate that the rolling treatment reduc…
Comparison of thermal expansion of wood and epoxy adhesives
Epoxy-based adhesives are used both in the consolidation of decayed timbers and for new structural joints. Investigating the compatibility of wood and epoxy adhesives provides a better knowledge of the long-term behaviour of wood-epoxy joints. Besides mechanical compatibility, also temperature-related parameters are relevant in this context. The values of the thermal expansion coefficients (TEC) of two wood species (Spruce, Picea abies and Iroko, Clorophora excelsa) and four different epoxy resins have been compared using a modified test method that allows for nearly iso-hygric conditions of the wood specimens. Minor differences in TEC have been observed between wood in the transversal-to-t…
Nudo femminile. Intervento di conservazione di un dipinto incompleto di Giacomo Manzù
L'opera di Giacomo Manzù (Bergamo 1908- Roma 1991) oggetto di questo lavoro, sebbene incompleta,presenta degli elementi che si possono riscontrare di frequente nell'ambito della produzione pittorica del Maestro. In particolare il dipinto, realizzato con tecnica mista su compensato, ci rimanda, anche per l'impostazione delle figure, ad altre due opere: Donna nuda con sedia, 1958, carbone su legno biacno e Donna con sedia, 1947, carbone matita e tempera. Dietro la tavola è posta inoltre un'etichetta del Gementeemuseum dell'Aia, Olanda, che ha permesso di individuare il titolo, Nudo femminile, e che testimonia la presenza temporanea del dipinto in una mostra allestita presso il museo olandese.…
The lining of the ancient cisterns in the volcanic island of Pantelleria
The paper deals with different types of lining of ancient cistern in Pantelleria,analysed by means of petrographical, physical and chemical analises. In spite of the abundance of pozzolana in the volcanic island, Punics and Roman preferred to use cocciopesto mortars.
Compressive recovery behaviour of a polycarbonate
Abstract Polycarbonate samples were subjected to large compression strains (beyond yielding) and were unloaded after some degree of stress relaxation. The subsequent deformation recovery was measured for several values of strain, loading rate and duration of stress relaxation. All the data could be reported as a single curve by normalizing the recovered strain with the stress at the end of the relaxation period.
L'Opinion Mining nelle Scienze Cognitive: espressione dei sentimenti e reti sociali
Le malte idrauliche dell’Acquedotto Romano di Termini Imerese
Aim of this paper is the characterization of ancient hydraulic mortars from the roman water supply system of Thermae (I-II cent. A.D.), known as “Aqua Cornelia” and "Figurella" aqueducts, more than 10 kilometers long. Because of malfunctioning of the "Barratina" siphon, major changes in the original adduction system were realized in several steps. Mortar samples were taken from both channels lining materials and structural elements, in order to contribute to answer some questions about the construction phases of the aqueduct. The materials characterization was performed by means of XRD analysis, optical microscopy, microRaman spectroscopy and simultaneous thermal analysis. The latter is a u…
Un soffitto ligneo intagliato miniato del XV secolo in Sicilia. Studio e Indagini Diagnostiche
A simplified description of viscoelastic behavior of polymers as illustrated with biaxially-oriented poly(ethylene terephthalate)
A rheological model of solid polymers is proposed. Its mechanical analog is a parallel of a linear spring and a Maxwell element with variable viscosity. The viscosity of the dashpot is allowed to change with stress both directly, by an Eyring-type mechanism, and through free volume changes according to the Doolittle equation. Predictions of the model reproduce many of the features shown, especially after yielding, by constant velocity stress-strain, stress-relaxation and creep data taken at room temperature on biaxially-oriented poly(ethylene terephthalate) over a wide range of loading rates.
Caratterizzazione dei residui di lavorazione di materiali lapidei di pregio, finalizzata ad un possibile recupero
A commercial low density polyethylene was irradiated by gamma irradiation at room temperature with different integrated doses and dose rates. The modifications induced in the material were studied by means of solubility and swelling measurements and related to structural modifications by calorimetric measurements. Results indicate that crosslinking prevails with respect to degradation at high dose rates and that the ageing phenomena occur essentially in the amorphous phase. Ein kommerzielles Polyethylen niedriger Dichte wurde bei unterschiedlicher integrierter Dosis und unterschiedlicher Dosisleistung bei Zimmertemperatur mit Gammastrahlung behandelt. Die Veranderungen des Materials wurden …
Towards a fuzzy-linguistic based social network sentiment-expression system
Liking allows users of Social Networks, blogs and online magazines to express their support of posts and artifacts by a simple click. Such function is very popular but lacks semantic power, and some platforms have augmented it by allowing to choose a pictographic depiction corresponding to a feeling. What is gained in depth is lost in simplicity, and the wide acceptance liking has enjoyed did not carried to the sentiment version. We outline a sentiment-expression hybrid system based on textual analysis and linguistic fuzzy Markov chains overcoming the intrinsic limitations of liking without burdening the user with complex choices.
Diagnostic Criteria for Parkinson's Disease: From James Parkinson to the Concept of Prodromal Disease.
The diagnosis of Parkinson’s disease (PD) is based on clinical features and differently to the common opinion that detecting this condition is easy, seminal clinico-pathological studies have shown that up one-fourth of patients diagnosed as PD during life has an alternative diagnosis at post-mortem. The misdiagnosis is even higher when only the initial diagnosis is considered, since the diagnostic accuracy improves by time, during follow-up visits. Given that the confirmation of the diagnosis of PD can be only obtained through neuropathology, to improve and facilitate the diagnostic-therapeutic workup in PD, a number of criteria and guidelines have been introduced in the last three decades.…
The Role of Cork Powder as a Filler for Epoxy Putties Used as Gap Fillers of Wood
Composizione, tessitura ed efficienza delle malte degli acquedotti Romani Cornelio e Figurella
Nell’ambito della conservazione dei beni culturali lo studio delle malte idrauliche a base di calce aerea rappresenta un tema di grande interesse per la complessità e la varietà dei materiali utilizzati e per l’importanza che hanno ri- vestito nella storia delle tecniche costruttive, grazie alle loro elevate prestazioni meccaniche e alla loro durabilità. L’Acquedotto Cornelio di Termini Imerese in Sicilia rappresenta un interes- sante esempio di costruzione idraulica, nella quale queste malte furono utiliz- zate sia per rivestire i condotti con strati impermeabilizzanti sia per conferire resistenza meccanica agli elementi strutturali. Un ulteriore elemento di interesse sta nella sua comples…
Indagini non Distruttive per una Migliore Conoscenza dei Documenti dell'Archivio Storico Diocesano di Palermo
Trace metals in “Posidonia oceanica” seagrass from south-eastern Sicily
Heavy-metal concentrations were measured in sediments and tissues of Posidonia oceanica seagrass from south-eastern Sicily (Italy) in order to assess the degree of metal pollution in the coastal area. Seagrasses and sediments were collected at four sites along the south-eastern coast of Sicily. Flame atomic absorption spectrophotometry (FAAS) was used to measure concentrations of Cu, Zn, Cd and Pb. Standard statistical analyses were used to assess significant differences among the levels of the elements measured in different tissues and sediment and spatial distribution. The greatest values of potentially toxic metal concentrations were observed at the station near the industrial sites of A…
L'uso di tecniche di microanalisi strumentale per la caratterizzazione di malte storiche con proprietà idrauliche
Characterization of mortars from ancient and traditional water supply systems in Sicily
Long aged mortars from ancient hydraulic constructions of Sicily, i.e. the Roman aqueduct of Thermae and the Punic cisterns and traditional water supply systems in Pantelleria, have been characterised by means of XRD analysis, optical microscopy and simultaneous thermal analysis to correlate the hydraulic properties to the texture and to their different role in the construction, i.e. lining, covering, roofing and joint mortars. According to a procedure proposed in the literature all of the samples, but two air hardening ones, show high hydraulicity, which somehow can be related to the characteristics of aggregates.