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

Sintesi e caratterizzazione allo stato solido ed in soluzione di derivati chinolonici di organostagno(IV)

I chinoloni sono antibiotici, recentemente usati anche come chemioterapici. Tra i derivati dell’acido nalidixico, precursore di tutte le classi di chinoloni, sono stati scelti chinoloni di I e II generazione per la sintesi di derivati di diorganostagno(IV). Questi composti sono stati caratterizzati sia allo stato solido che in soluzione con spettroscopia FT-IR, Mössbauer, 1H NMR, e con spettrometria di massa (ES-MS).

Rapid One-Step Fabrication of Graphene Oxide-Decorated Polycaprolactone Three-Dimensional Templates for Water Treatment

Coating of flexible substrates is crucial to prepare versatile, multifunctional materials. However, exploration of effective fabrication approaches is still a challenging issue, because the pathways generally proposed require time-consuming, multistep protocols. Here, we developed a one-pot process for decorating either pearl necklace-like or fibrous fluffy-like structures of polycaprolactone (PCL) with graphene oxide (GO) skin. PCL solutions were dry jet-wet electrosprayed or electrospun into a stirred liquid collector constituted by ethanol-containing GO nanoparticles. The stirred liquid collector enables the formation of 3D-structures, whose microarchitecture can be designed by controlli…

IL RESTAURO DELLA STATUA LIGNEA DORATA RAFFIGURANTE SANT’AGATA STUDIO SPERIMENTALE SUI MATERIALI PER L’INTEGRAZIONE DI PARTI LIGNEE MANCANTI

In questo articolo si presenta l’intervento di restauro della statua lignea dorata, raffigurante Sant'Agata e scene di vita della Santa, eseguito nell’ambito di una tesi di laurea in Conservazione e Restauro dei Beni Culturali e la sperimentazione, ad essa collegata, sul comportamento meccanico e la compatibilità con il legno di alcuni materiali per stuccatura e reintegrazione. L'opera originariamente conservata presso il magazzino loggiato della Galleria Interdisciplinare Regionale della Sicilia di Palazzo Abatellis, è stata spostata presso l’oratorio dei Bianchi di Palermo per l’intervento di restauro svoltosi a cantiere aperto, per la prova di laurea magistrale in Conservazione e Restaur…

La conservazione di opere policrome in Norvegia e in Italia: confronto e incontro tra la metodologia e la cultura del restauro nei due paesi

COMPARISON OF CRIMSON FOUNTAINGRASS AND DISS FIBRES AS AGGREGATES FOR CEMENT MORTARS

The use of natural fibres in cement composites is an expanding research field as their use can improve the mechanical and thermal behavior of cement mortars and reduce their carbon footprint. In this paper two different wild grasses, i.e. Pennisetum Setaceum, also known as crimson fountaingrass, and Ampelodesmos Mauritanicus, also called diss, are used as source of natural fibres for cement mortars. The principal aim is to evaluate the possibility of using the more invasive crimson fountaingrass in place of diss inside cement based vegetable concrete. The two plants’ fibres have been characterized by means of electron microscopy, helium picnometry; moreover, the thermal conductivity of fibr…

IL RESTAURO DELLA STATUA IN STUCCO “LA PENITENZA” NELLA CHIESA DI SANTA NINFA DEI CROCIFERI A PALERMO

In questo lavoro viene presentato il restauro della statua in stucco rappresentante l’allegoria della Penitenza di scuola Serpottesca. L’opera si trova nella chiesa di Santa Ninfa dei Crociferi a Palermo e fiancheggia l’altare della cappella della Madonna della Salute insieme all’allegoria della Giustizia. L’opera non è autografa, nulli sono gli atti che ne documentano con certezza l’identità, ma è inequivocabile la sua appartenenza alla scuola dei Serpotta, la più importante bottega di maestri stuccatori del barocco siciliano, il cui massimo esponente è stato Giacomo. Il manufatto versava in condizioni di conservazione drammatiche principalmente a causa di, ormai risolte, ingenti infiltraz…

The open metastable structure of a collapsible sand: fabric and bonding

This paper deals with the compositional and textural characteristics determining open metastable structures in the pleistocenic sand outcropping in the Agrigento district (Sicily). The aim of the study was to individuate the bonding types occurring between grains that could generate matric suction phenomena. The composition and microfabric were characterised by means of granulometry, porosimetry, permeability, optical and ESEM-EDS microscopy, thermogravimetry and XR diffractometry, electric conductivity, and ionic chromatography. The data thus acquired show that the skeleton of the sand is constituted mostly by bioclasts and microfossils, calcite and quartz monocrystalline grains. Moreover,…

Progetto di recupero e conservazione della Villa Romana del Casale di Piazza Armerina. Indagini chimico fisiche sulle malte di allettamento e di finitura

Electronic Properties of Thermal Oxides on Ti and Their Influence on Impedance and Photoelectrochemical Behavior of TiO2 Nanotubes

Thermal oxidation of titaniumwas carried out at 350◦C, 450◦C, and 550◦C for 2 h or 12 h.X-rayDiffraction and Raman Spectroscopy suggest that the thermal oxides are scarcely crystallinewhen the annealing temperature is low, while both anatase and rutile are present for high annealing temperature and time. Photoelectrochemical measurements allowed estimation of a bandgap decreasing from 3.35 eV to 3.15 eV with increasing annealing temperature. The impedance spectra confirmed the formation of n-type semiconductors, with an impedance strongly decreasing on going from a reverse bias toward a forward bias regime. TiO2 nanotubes grown by anodizing Ti in NH4F and water containing ethylene glycol so…

Floor and wall mortars of archaeological site of Selinunte , Sicily

Polychrome wood sculpture depicting The Madonna del Soccorso or della Mazza from the Archdiocese of Palermo: an integrated analytical approach for the restoration

In this study the Madonna del Soccorsoo della Mazza wooden sculpture has been analysed by an interdisciplinary and integrated approach. The polychrome sculpture, dating back to the 18thcentury, comes from the church of the Madonna del Soccorso or della Mazza (1604) situated in Via Maqueda, in Palermo and it was placed on the main recess of the altar. All steps of the conservation project, from the preliminary study to the choice of materials and the restoration procedures have been accompanied and supported by diagnostic and scientific analysis. In order to evaluate the state of conservation of the sculpture and the technique employed to construct the support, computer tomography study was …

L'USO DELLE CARICHE CELLULOSICHE PER MIGLIORARE LA COMPATIBILITA' COL LEGNO DEI MATERIALI POLIMERICI UTILIZZATI NELLA STUCCATURA DELLE FESSURE

Structure-property relationship of PLA-Opuntia Ficus Indica biocomposites

Abstract In this work, a lignocellulosic flour was achieved by grinding the cladodes of Opuntia Ficus Indica and then added to a poly-lactic acid (PLA) in order to prepare biocomposites by melt processing. The influence of filler content and size on the morphological, rheological, and mechanical properties of the green composites was assessed. Moreover, solvent-aided filler extraction enabled to evaluate the homogeneity of filler dispersion, as well as the effect of processing on the geometrical features of the fillers. The experimental data obtained by tensile tests proved to be remarkably higher than those predicted by Halpin–Tsai model, presumably due to the capability of the polymer to …

INDAGINI DIAGNOSTICHE PROPEDEUTICHE AL RESTAURO DELLA SALA DEI VENTI DI PALAZZO DEI NORMANNI A PALERMO

La Sala dei Venti è uno dei più suggestivi luoghi del Palazzo dei Normanni a Palermo, si tratta di una struttura sita all’interno della Gioaria, una torre medievale dell’originale nucleo arabo-normanno, antistante la Sala di Ruggero, coperta da un soffitto ligneo dipinto, risalente al XVIII secolo, al centro del quale campeggia una rosa dei Venti che dà il nome all’ambiente. Le porzioni superiori delle pareti e la copertura, soggette nel tempo a numerosi restauri e rifacimenti, presentano una ricca decorazione dipinta suddivisa in tre livelli: quello superiore costituito dal soffitto dipinto (parzialmente incamottato); quello intermedio costituito dai dipinti murali con decorazioni a finto …

Induced Modification of Flexural Toughness of Natural Hydraulic Lime Based Mortars by Addition of Giant Reed Fibers

Abstract Nowadays, there is a growing need to reduce the environmental impact generated by the use of inorganic materials for building applications. The aim of this work is to investigate the bio-lime based mortar flexural toughness improvement due to the addition of common reed fibers (Arundo donax L.) in order to evaluate their possible application as ductile eco-compatible prefabricated bricks or laying and joint mortars for masonry. Different sets of specimens were tested by varying the fiber weight content and the fiber length. Moreover, chemical treatments with Linseed Oil and Polyethylene glycol (PEG) were performed to improve the physical and mechanical properties of the fibers as w…

Semiconducting properties of passive films and corrosion layers on weathering steel

Abstract Anodic films were grown on Weathering Steel by potentiostatic polarization in slightly alkaline solution. The photoelectrochemical results reveal that they are n-type iron oxide with Eg = 2.0 eV. Rust layer grown by atmospheric corrosion are n-type semiconductors with a band gap higher than that estimated for the anodic film attributed to the formation of γ-lepidocrocite. The electrochemical impedance spectra allow to evidence that rust layers have a higher conductivity with respect to anodic films due to the presence of highly doped iron oxide layers. The use of Mott-Schottky theory to model the dependence of oxide capacitance as function of potential is critically discussed.

Influence of application method on the use of ammonium phosphate as preservative

This work deals with the application of the Ammonium Hydrogen Phosphate as preservative and consolidant during the restoration and consolidation intervention on a twin columns group in the east side of the Santa Maria La Nova Cloister in Monreale, UNESCO Heritage from 2016. The Superintendency for Fine Arts in Palermo prescribes the use of ammonium phosphate as the only acceptable material for the consolidation of the Cloister, so this work deals with the influence of application method and solution concentration on the results achievable with this material. Particularly as the treatment have to be done on vertical surfaces the use of a supporting material is mandatory so the focus is on th…

Misura degli inquinanti atmosferici

Tunable radical scavenging activity of carbon nanotubes through sonication

Abstract Carbon nanotubes (CNTs) having controlled radical scavenging activity have been achieved tuning the content of their lattice defects induced by an ultra-sound (us) treatment. The reactivity of CNTs, subjected to ultra-sonication for different time intervals, toward 1,1-diphenyl-2-pycryl (DPPH) and hydroxyl (•OH) radicals has been estimated and related to defect concentration, evaluated through Raman spectrometry. The radical scavenging efficiency of ultra-sound treated CNTs (us-CNTs) increases with increasing the content of the structural defects, suggesting that the defect resulting from us treatment can be capitalized to obtain an amplified and controlled radical scavenging activ…

Improved Cu2O/AZO Heterojunction by Inserting a Thin ZnO Interlayer Grown by Pulsed Laser Deposition

Cu2O/ZnO:Al (AZO) and Cu2O/ZnO/AZO heterojunctions have been deposited on glass substrates by a unique three-step pulsed laser deposition process. The structural, optical, and electrical properties of the oxide films were investigated before their implementation in the final device. X-ray diffraction analysis indicated that the materials were highly crystallized along the c-axis. All films were highly transparent in the visible region with enhanced electrical properties. Atomic force and scanning electron microscopies showed that the insertion of a ZnO layer between the Cu2O and AZO films in the heterojunction enhanced the average grain size and surface roughness. The heterojunctions exhibi…

Assesment of the Conservation State of Stone Materials in Relation to the Level Environmental Pollution in the Conservation Place

The patina represents a superficial natural alteration of the constituting matter of the work of art. It emerges from the natural and usual stabilization process that the materials of the surface undergo because of the interaction with outdoor agents characterizing the surrounding environment. Besides, it is not linked to an obvious phenomenon of degradation that can be noticed through the change in the original colour of the matter. This is what we intend when we talk about biological patina usually generated by macro and/or micro-organic colonization (fungi, bacteria, alga) which contributes to surface bio-deterioration and thus lead to the formation of orange, red or even brown and dark …

NEW APPLICATIONS IN THE USE OF CELLULOSE PULP FOR THE INTEGRATION OF WOODEN SUPPORTS

Cellulose pulp, mainly utilized as a support for cleaning stone material, in this study, is proposed as a filler for wooden supports. In the last 10 years, pulp has been used in many restoration works carried out in the laboratory of the Diocesan Museum (MDP) in Palermo, including both wooden sculptures and panel paintings. These artworks, exhibited in the MDP, are constantly monitored in order to evaluate the effectiveness of cellulose pulp as a filler, assessing its durability and bio-receptivity. In particular, structural characteristics, drying time, shrinkage, loss in weight, affinity to the pigments, etc., were simultaneously evaluated. Tests were also carried out on artificially aged…

The effect of Annealing Conditions on the Impedance and on the Photoelectrochemical behavior of TiO2 Nanotubes

Titanium oxide nanotubes (NTs) have attracted much attention during last decade due to their special characteristics such as one-dimensional highly ordered geometry with large surface area and good chemical and optical stability.

Collapsible intact soil stabilisation using non-aqueous polymeric vehicle

Abstract This paper presents the results of an experimental study that had the goal of understanding the effects of treatment with polyethylene glycol (PEG)/nanolime mixtures on collapsible soil behaviour. In a previous study, the use of pure PEG offered a good improvement in the stability of collapsible soil, but the stabilisation effect only lasted for a limited time. To investigate the stabilisation potential of PEG/nanolime systems for collapsible sand, different mixtures were prepared at increasing nanolime weight ratios. The suitability of the stabilised soil was examined on the basis of collapsibility, oedometer, shear, and water vapour permeability tests, and through optical microsc…

Analysis of the chemical and microstructural modifications effects on the hydro-mechanical behaviour of a lime-treated clay

The paper presents the results of a characterization of kinetic characteristics of pozzolanic reaction with the aim to investigate the time-dependent modification of clay properties as a consequence of mixing with lime. Results of chemical analyses are in agreement with the increase of mechanical properties and with the observed microstructure modifications up to one year of curing time. The rate of development of pozzolanic reactions seems to be almost constant while the time required for their completion is dependent on the lime content. Pozzolanic products are responsible for the time reduction of swelling strain upon saturation as well as for the increases of yielding stress, stiffness …

The Effects of Structure on the One Dimensional Compression Behaviour of a Porous Calcarenite

Human settlements built on weak rock deposits are often characterized by instabilities or collapse that may involve the underground cavities and consequently the above buildings. Underground calcarenite quarries in Marsala have been involved in a number of collapses that have seriously damaged numerous buildings. Unfortunately proper engineering solutions have not yet been identified according to the different and special cases and to the properties of this structured material. In order to investigate structure effects on the behaviour of the porous calcarenite of Marsala, this paper presents a comparison between the one dimensional compression behaviour of the intact rock and of the same w…

Studio tecnico dei materiali costitutivi e delle tecniche esecutive delle cornici lignee in Sicilia

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 …

Studio dei dipinti murali nella chiesa del Monastero di Bodjani consacrata alla presentazione della Madonna al Tempio

La tecnologia laser nella pulitura dei manufatti lapidei, casi studio a confronto

In questo lavoro viene presentata la sperimentazione condotta, nell’ambito di una tesi di Laurea Magistrale a Ciclo Unico in Conservazione e Restauro dei Beni Culturali, presso l’Istituto di Fisica Applicata “Nello Carrara” del Consiglio Nazionale delle Ricerche di Firenze, per valutate le potenzialità di diversi regimi laser Nd:YAG a 1064 nm: Short Free Running (30 - 110 μs) e Long Q-Switch a singolo, doppio e triplo impulso (120 ns distanziati tra loro da 40 µs). A tale scopo sono stati selezionati alcuni frammenti di manufatti lapidei, di diverso periodo storico, databili tra il XVII secolo a.C. e il XX secolo, che offrivano problematiche conservative di particolare interesse. La conosce…

Determination of the crystallinity of TiO2 photocatalysts

Abstract This study reports a new simple method to determine the crystallinity of anatase and rutile TiO2 photocatalysts. The crystallinity degree of various anatase and rutile samples was estimated by XRD analysis from the ratio among the full width at half maximum intensities of the main diffraction peaks of anatase or rutile and the (111) peak of CaF2 as internal standard. The photocatalytic activity of selected powders was tested employing the photodegradation of 4-nitrophenol in aqueous solution as probe reaction. The results showed that the photoactivity of the investigated samples increased with increasing crystallinity and crystallite size.

The Peer Obervation: "Mentore" Project at the University of Palermo

During the last six years, at the University of Palermo, a group of academics has been involved in a project called “MENTORE” (“Modifying and ENhancing Teaching through peer Observation and Reflections with Experts”). The objectives of the project are: to help teachers improve their teaching, through the help of two mentors; to experiment new approaches in pilot courses to extend, if useful, to other ones; and to change the traditional model of academic teaching based on one single teacher with the class to go towards a model where there is a group of teachers working together in search of improvements. All the participants of the MENTORE project attend to lectures/workshops on teaching and…

Evaluation of Cement Content in Hardened Concrete

SrTiO 3 -based perovskites: Preparation, characterization and photocatalytic activity in gas–solid regime under simulated solar irradiation

Strontium titanate-based perovskites have been prepared in the presence of Y and Co with the aim to substitute Sr and Ti, respectively, in the ST crystalline structure. The obtained samples have been characterized by XRD, Raman spectroscopy, FE-SEM, XPS and tested as photocatalysts in two gas-solid regime reactions: (i) 2-propanol complete mineralization and (ii) propene partial oxidation, using a system simulating solar irradiation. All the tested samples resulted active as photocatalysts but with significant differences. The lattice substitution of Sr by Y displays a beneficial effect on the 2-propanol photodegradation. Conversely, the partial presence of cobalt on the ST surface, as Co-o…

Note preliminari sulla caratterizzazione di alcuni materiali

Osservazioni sulla successione stratigrafica degli stucchi della scuola di Giacomo Serpotta a Palermo

Characterization of hydraulic mortars from roman aqueducts of thermae (Sicily)

Alkali activated materials using pumice from the Aeolian Islands (Sicily, Italy) and their potentiality for cultural heritage applications: Preliminary study

Abstract In this paper, the potentialities of pumice-based geopolymers have been explored with the aim to evaluate their use as restoration materials. In particular, the behaviour of Aeolian pumice during alkali activation process, either alone or in binary mixtures with metakaolin, has been assessed using sodium hydroxide and sodium silicate activators. Hardened products were characterized by: X-ray diffraction; infrared spectroscopy; thermo gravimetry and electron microscopy. Furthermore, Hg-intrusion porosimetry, water absorption, compressive strength and colorimetric measurements were carried out in order to define the technical features of the produced geopolymers. The results reveal t…

UN PROCEDIMENTO PER IL TRATTAMENTO DI ACCIAIO ZINCATO

La zincatura viene comunemente effettuata su acciaio al carbonio per impartigli una protezione attiva, ossia una protezione catodica per anodo sacrificale, oltre che una protezione fisica di tipo barriera. La zincatura potrebbe essere utilizzata anche per barre di armature nel calcestruzzo armato nei casi in cui strutture debbano essere fabbricate in ambienti particolarmente aggressivi, quali atmosfere marine e/o industriali, dove il composito calcestruzzo/metallo può subire carbonatazione e/o attacco da cloruri. Tuttavia, la zincatura ha un effetto collaterale, ossia diminuisce l’aderenza delle barre causando problemi alla struttura. Questa controindicazione ne ha limitato l’uso in questo …

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…

Thymus vulgaris Essential Oil and Hydro-Alcoholic Solutions to Counteract Wooden Artwork Microbial Colonization

Aromatic plants represent a source of natural products with medicinal properties, and are also utilized in the food and pharmaceutical industries. Recently, the need for eco-compatible and non-toxic products, safe for both the environment and human health, have been proposed for the sustainable conservation of historic–artistic artifacts. In this study, in order to counteract microbial colonization (Aspergillus sp., Streptomyces sp., Micrococcus sp.) on wooden artwork surfaces, Thymus vulgaris L. (Lamiaceae) essential oil (EO) and hydro-alcoholic (HA) solutions were applied in a polyphasic approach. The antimicrobial activities of EO and HA solutions were preliminarily assessed by agar disc…

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…

Giacomo Serpotta and the stuccoers of Palermo: aspects of materials used in refined decorative activity. The costitutive materials

Physical and mechanical properties of sustainable hydraulic mortar based on marble slurry with waste glass

This paper aims to propose and characterize a sustainable hydraulic mortar entirely obtained by the reuse of waste materials, with marble slurry coming from quarries in the north-western Sicily and glass powder coming from a waste collection plant in Marsala (Province of Trapani). The first was used as raw material to produce the mortar binder by a kilning and slaking process, while the second was used as a pozzolanic additive. The chemical and morphological characterization of the marble slurry was done by XRD, FTIR, STA and SEM analyses. Glass powder was analyzed through particle size distribution measurements, XRD and standard pozzolanic tests. Hydraulic mortars constituted by slaked lim…

Synthesis and Characterization of organotin (IV) derivates of nalidixic acid

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.

Improvement of oxidation resistance of polymer-based nanocomposites through sonication of carbonaceous nanoparticles

Abstract The work aim is focused on two different aspects: first, the investigation of the effect of extended ultra-sound-assisted treatment (us) of carbonaceous nanoparticles, such as carbon nanotubes (CNTs) and carbon black (CB), on their radical scavenging activity, and second, the investigation of the oxidative resistance of polymer-based nanocomposites, containing us-treated CNTs and CB. Particularly, the CNTs and CB have been subjected to us sonication for different time intervals and the performed analysis reveals that both kinds of nanoparticles show decreased average hydrodynamic diameters and large content of surface defects. Really, the increased content of CNTs and CB defects, a…

The skill in materials selection and processing at the Serpotta's studio during the baroque period in Palermo

L''identificazione del legno nelle opere policrome in Sicilia

La Madonna della Lavina di Cerami: preentazione estetica, osservazione dei materiali di restauro

Restoration of a XVII Century’s predella reliquary: From Physico-Chemical Characterization to the Conservation Process

We report on the restoration of a XVII century’s predella reliquary, which is a part of a larger setup that includes a wall reliquary and a wooden crucified Christ, both belonging to the church of “Madre Maria SS. Assunta”, in Polizzi Generosa, Sicily, Italy. The historical/artistic and paleographic research was flanked successfully by the scientific objective characterization of the materials. The scientific approach was relevant in the definition of the steps for the restoration of the artefact. The optical microscopy was used for the identification of the wood species. Electron microscopy and elemental mapping by energy-dispersive X-ray (EDX) was successful in the identification of the l…

Calcestruzzi delle Aviorimesse per Idrovolanti di Pier Luigi Nervi a Marsala (1940-41). Composizione e Tessitura

Comparative study between four consolidation systems suitable for archaeological bone artefacts

This study started with the restoration of a 14th century Italian crosier during the final Master year project at the Institute National du Patrimone in Paris (Palazzo 2014). The characterization and consolidation of the bone materials constituting the crosier was needed due to its poor state of conservation. Several products, both organic polymers and inorganic consolidants applied on artificially altered bone material underwent scientific investigations consisting of several analyses and mechanical tests in order to choose the most suitable for the restoration intervention. The results thus obtained showed that both nanolime and a mix of Paraloid® and calcium phosphate seem to be adequate…

Halloysite nanotubes-based nanocomposites for the hydrophobization of hydraulic mortar

Abstract The treatment of stone surfaces for their protection from ageing caused by natural and anthropogenic effects is an open issue in materials development for Cultural Heritage. We thought interesting to verify the suitability of a modified cellulose biofilm filled with halloysite nanotubes as wax compatibilizers to design a protecting layer. A hydraulic mortar was selected as a stone prototype. To improve the physico-chemical properties of the covering layer, wax microparticles have been incorporated to control transport, consolidation and wettability features. In particular, different application protocols have been studied, namely brushing and spraying, to assess whether the propos…

Anodic Electro Deposition of CeO2 and Co-Doped CeO2 Thin Films

CeO2 and Co containing CeO2 thin films were deposited on indium tin oxide and stainless steel by anodic electrodeposition. Scanning electron microscopy showed that the films are flat and show globular morphology and cracks resulting from volume shrinking. According to XRD and Raman Spectroscopy pure ceria layers are crystalline, while the presence of Co induces the formation of amorphous films. The good adhesion and the compactness allowed the photoelectrochemical characterization of the films. A band gap value of 2.9 eV was estimated for CeO2, while slightly higher values (̃3.0 eV) were estimated for Co containing films. A mechanism for ceria anodic electrodeposition is proposed and discus…

Characterization of serpottas' stuccos by means of simultaneous thermal analysis: Preliminary results

In this paper the Simultaneous Thermal Analysis (STA), i.e. thermogravimetric and differential thermal analysis, was used as a diagnostic tool to better understand the matter composition of some very valuable artworks the Serpottas’ stuccoes in Palermo. Particularly the STA was used in order to exclude the presence of an unusual calcium-bearing magnesium carbonate, and the thermal data were also used to quantify the magnesite to calcite ratio. The latter was investigated in order to evaluate the amount of magnesium in the lime used as binder as during 17th and 18th century in Sicily magnesium rich lime was indicated as the most valuable binder probably because this kind of lime has a higher…

Preparation, thermal analysis and photoactivity of TiO2 samples

Effect of the Si doping on the properties of AZO/SiC/Si heterojunctions grown by low temperature pulsed laser deposition

Abstract The structural and photoelectrical properties of Al-doped ZnO (AZO)/SiC/p-Si and AZO/SiC/n-Si heterojunctions, fabricated at low temperature by pulsed laser deposition, were investigated by means of a number of techniques. Raman analysis indicates that SiC layers have the cubic 3C-SiC phase, whilst X-ray diffraction measurements show that AZO films exhibit a hexagonal wurtzite structure, highly textured along the c-axis, with average crystallites size of 35.1 nm and lattice parameter c of 0.518 nm. The homogeneous and dense surface morphology observed by scanning electron microscopy was confirmed by atomic force microscopy images. Moreover, UV–Vis-NIR spectra indicated a high trans…

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…

The influence of Al doping on the photocatalytic activity of nanostructured ZnO: The role of adsorbed water

Abstract Al doped ZnO nanoparticles (labeled as x% A-ZnO, x = 0.0, 0.5, 1.0, and 1.5) were synthesized by a simple sol-gel method, characterized and tested as photocatalysts for the degradation of a model compound under UV-light irradiation. Diffuse reflectance spectroscopy (DRS) and photoelectrochemical analysis have been performed to evidence their optical and electronic behavior. The structural features of the powders were highlighted by means of specific surface area (SSA) analysis, X-ray diffraction (XRD), Fourier-transform infrared (FTIR) and Raman spectroscopy. Al doping results in enhanced photocatalytic activity of the modified powders with respect to pure ZnO. In particular, the h…

Controlling Thermal Flows through Natural Materials in Building Construction Sector

Nowadays, the attention about the building sustainability is increasingly emerging, because of the major responsibility of the building field on the environmental degradation: both in terms of energy consumption from non-renewable sources and the raw materials impoverishment. In addition, the level of comfort required by users is growing and the thermal insulation of buildings becomes the key element for the reduction of energy consumption and CO2 emissions, both in the case of new construction and of the existing ones. The heat load of a building depends on the presence of insulating material which defines the performance of the building envelope. The main purpose of this work is both to i…

Natural and accelerated weathering of two coloured siclian building stones

Photocatalytic oxidation of trans-ferulic acid to vanillin on TiO2 and WO3-loaded TiO2 catalysts

Abstract The photocatalytic oxidation of trans-ferulic acid to vanillin in water has been studied by using various TiO2 and WO3-loaded TiO2 samples as catalysts. Different values of selectivity were obtained depending on the physico-chemical properties of the single samples and a vanillin selectivity of 10% was reached in the presence of the commercial TiO2 Merck. Higher selectivity values were obtained by impregnation of TiO2 with H2WO4 followed by calcination. The increased production of vanillin exhibited by the obtained WO3-loaded TiO2 powders was attributed to a reduced further oxidation of the aldehyde caused by the presence of the practically inactive tungsten trioxide hydrate on the…

The restoration of the North-East corner columns of Santa Maria La Nova the cloister in Monreale, Italy

Lo scopo della presente ricerca è quello di descrivere i risultati dello studio, con la rappresentazione tramite scanner laser 3D, e del restauro scientifico, che ha previsto anche una reintegrazione, del gruppo di colonne posto nell'angolo Nord-Est del famoso chiostro dell'Abbazia di Santa Maria La Nova in Monreale, vicino Palermo, Italia (ultimo quarto del XII secolo) The purpose of the present research is to describe the results of the study, with 3D laser scanner representation, and scientific restoration, which also included reintegration, of the group of columns located in the northeast corner of the famous cloister of the Abbey of Santa Maria La Nova in Monreale, near Palermo, Italy …

Mechanical and Thermal Properties of Insulating Sustainable Mortars with Ampelodesmos mauritanicus and Pennisetum setaceum Plants as Aggregates

The use of natural fibers in cement composites is a widening research field as their application can enhance the mechanical and thermal behavior of cement mortars and limit their carbon footprint. In this paper, two different wild grasses, i.e., Ampelodesmos mauritanicus, also called diss, and Pennisetum setaceum, also known as crimson fountaingrass, are used as a source of natural aggregates for cement mortars. The main purpose is to assess the possibility of using the more invasive crimson fountaingrass in place of diss in cement-based vegetable concrete. The two plant fibers have been characterized by means of scanning electron microscopy (SEM), helium picnometry and thermogravimetric an…

NATURAL AND ACCELERATED WEATHERING OF TWO COLOURED SICILIAN BUILDING STONES

Il restauro della lunetta dipinta: "Cristo e l'Eterno ai lati del mondo"

Oggetto del nostro contributo è lo studio ed il restauro della lunetta dipinta raffigurante “Cristo e l’Eterno ai lati del mondo” realizzata da Simone de Wobreck nel 1562. L’intervento è stato realizzato come prova abilitante alla professione nell’ambito delle attività laboratoriali del Cdl in Conservazione e Restauro dei Beni Culturali, dell’Università di Palermo, con la direzione della Galleria Regionale di Palazzo Abatellis [1]. Di particolare interesse è stato lo studio dell’opera in relazione alla tecnica esecutiva utilizzata dall’autore, allo stato di conservazione ed ai precedenti interventi che l’opera ha subito negli anni. La tavola dipinta raffigura Cristo e l’Eterno ai lati del m…

The wall paintings of the Roman Villa at Piazza Armerina in Sicily

Il restauro dello "Scheletro in marmi mischi" della Galleria Abatellis: dalla colofonia naturale ai prodotti di sintesi. Sperimentazione di formulati adesivi per elementi marmorei

Il lavoro qui presentato ha per oggetto il restauro di un frammento di tarsia marmorea rappresentante uno scheletro, probabilmente in origine collocato all’interno di una cripta o facente parte di un cenotafio o di un monumento sepolcrale, custodito all’interno dei depositi della Galleria Interdisciplinare Regionale della Sicilia di Palazzo Abatellis a Palermo. Della scultura ad alto rilievo, in marmo di Carrara, non si hanno notizie documentarie certe circa l’anno di realizzazione e l’autore, pur potendosi collocare, per lettura analogica con produzioni simili per stile e destinazione, attorno al XVII secolo. Inoltre, l’attento studio dei materiali costitutivi ha permesso di aggiungere un …

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.

One-step electrodeposition of superhydrophobic coating on 316L stainless steel

Superhydrophobic coatings were fabricated through a one-step electrochemical process onto the surface of 316L stainless steel samples. The presence of hierarchical structures at micro/nanoscale and manganese stearate into the coatings gave superhydrophobicity to the coating, with contact angle of ~160°, and self-cleaning ability. Corrosion resistance of 316L samples was also assessed also after the electrodeposition process through Electrochemical Impedance Spectra recorded in an aqueous solution mimicking seawater condition.

DEGRADATION OF STUCCO WORKS OF SERPOTTA SCHOOL IN PALERMO AS RELATED TO THE CONSERVATION ENVIRONMENTAL CONDITIONS

Durability of biodegradable polymers for the conservation of cultural heritage

The use of polymers for conservation of cultural heritage is related to the possibility to slow down or stop natural deterioration which, in many cases, corresponds to stopping the entrance of liquid water and to favour spontaneous water vapour removal. Unfortunately, hydrophobicity is generally favoured by surface roughness and thus competitive with transparency. It is therefore important to find an optimal balance hydrophobicity, transparency and durability (especially to photooxidation). However, polymers typically used for applications in this field come from non-renewable resources and are not biodegradable. In this work, the mechanical, structural and optical properties of PLA, PBAT a…

La caratterizzazione delle malte dell'acquedotto Cornelio di Termini Imerese

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.…

Collapsibility of metastable sand by non-conventional oedometer tests

The stability of foundations soils could represent a clear and present threat for the conservation of even well preserved buildings, particularly for Architectural heritage conservation and land art heritage. A dramatic case is the presence of collapsible metastable sands as foundation soils, as it occurs in the sacral complex Valle dei Templi in Agrigento. This site listed by UNESCO, stands on a crest of a calcarenite cuesta, overlaying a layer of these sands. When the collapsible sand is dry, the structure is strong enough to bond the sand particles together. When the sand becomes wet, a de-structuration mechanism occurs and the soil’s strength is compromised. This paper has a twofold aim…

FORMULATION OF LIME MORTARS BASED ON NATURAL FIBERS AND WASTE MATERIALS FOR MORE SUSTAINABLE BUILDINGS

Nowadays sustainability is one of the main concept in building construction, both considering energy saving buildings and life cycle assessment of building materials. According to these considerations, in this work the use of recycled and waste materials to produce a binder and the use of a natural fiber as reinforcement are investigated to obtain a sustainable mortar. Particularly, lime is obtained by kilning waste marble slurry from marbles quarries in western Sicily; pozzolanic aggregate is obtained by grinding glass powder from urban waste collection; natural fibers come from a widespread grass: Ampelodesmos Mauritanicus also known as diss. Scanning electron microscopy and helium picnom…

Heterogeneous crystallization of zinc hydroxystannate on galvanized steel for enhancing the bond strength at the rebar/concrete interface

Abstract Zinc hydroxystannate (ZnSn(OH)6) coatings were deposited on galvanized carbon steel samples by an electroless heterogeneous crystallization process. Structural and morphological features of the coatings as a function of the immersion time were determined by X-ray diffraction, Raman Spectroscopy and Scanning Electron Microscopy revealing the presence of truncated octahedrons of crystalline ZnSn(OH)6. Electrochemical characterization in a simulated concrete pore solution without and with addition of chloride ions proved that the cathodic protection is preserved and that ZnSn(OH)6 improved the corrosion resistance of the rebars. Pull-out tests demonstrated an enhanced bond strength at…

The Peer Observation: “Mentore” Project at University of Palermo

During the last 6 years at the University of Palermo, a group of academics has been involved in a project called “MENTORE” (“Modifying and ENhancing Teaching through peer Observation and Reflections with Experts.”) The objectives of the project are to help teachers improve their teaching, through the help of two mentors; to experiment new approaches in pilot courses to extend, if useful, to other ones; and to change the traditional model of academic teaching based on one single teacher with the class to go toward a model where there is a group of teachers working together in search of improvements. All the participants of the MENTORE project attend to lectures/workshops on teaching and lear…

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…

INDUCED MODIFICATION OF FLEXURAL TOUGHNESS OF BIO-LIME BASED MORTARS BY ADDITION OF GIANT REED FIBERS

Fibers are often used as reinforcement of brittle materials, like mortars, in order to modify their mechanical behavior; particularly the modification in post-cracking toughness, induced by low elasticity modulus fibers in the artificial stone material, is the main goal in natural fibers mortar manufacturing. In this work Arundo donax L. fibers are used to reinforce lime mortars according to the characteristics of this plant, very commonly available and with high mechanical properties, similar to bamboo, traditionally used in buildings in Spain. Influence of fibers’ length and weight ratio is studied. Particularly, three different fibers’ lengths, 4, 8 and 12 centimeters, and three weight r…

Measure of a limestone weathering degree using Laser Scanner.

The weathering degree of the building materials and natural stones is generally quantified as the decrement of some mechanical features that can be measured experimentally by means of compressive tests or point load tests in the laboratory or Schmidt hammer tests carried out in situ. Such destructive or damaging tests are unacceptable in case of cultural heritage since even small amounts of damage must be avoided. This work shows a correlation between Schmidt hammer rebound values and the reflectivity that is detected by means of terrestrial scanner laser; therefore it allows assessing the weathering degree of buildings or stones in situ. The results demonstrate that such an investigation c…

Un soffitto ligneo intagliato miniato del XV secolo in Sicilia. Studio e Indagini Diagnostiche

INDAGINI SPERIMENTALI SU MALTE TRATTATE CON SILICATO DI LITIO NANODISPERSO DA UTILIZZARE PER STUCCATURE DI MATERIALI LAPIDEI COMPATTI

In questo lavoro di ricerca, sviluppato all’interno della tesi di laurea magistrale in Conservazione e Restauro dei Beni Culturali presso l’accademia Galli di Como con la supervisione della restauratrice Gisella Bianconi, si è sperimentato l’uso del silicato di litio come additivo per il miglioramento delle prestazioni di malte a base di leganti inorganici, e in particolare calci aeree e idrauliche, utilizzate nel restauro dei materiali lapidei. Spesso per le stuccature di materiali lapidei compatti vengono utilizzate malte con leganti organici, ed in particolare di tipo epossidico, che offrono certamente ottime proprietà meccaniche e un’eccellente adesività, garantendo al contempo una acce…

tudio tecnico dei materiali costitutivi e delle tecniche esecutive delle cornici lignee in Sicilia

I DIPINTI MURALI STACCATI: CRITICITÀ E NUOVE PROPOSTE

La tesi di Laurea Magistrale a ciclo unico, in "Conservazione e Restauro dei Beni Culturali", della Dottoressa Nicoletta Chiparo, riguarda l'intervento di restauro di un lacerto di dipinto murale staccato, di età paleocristiana, raffigurante un'orante; l’approccio alle problematiche di conservazione del dipinto murale ha suggerito l’avvio di una ricerca bibliografica e di laboratorio sui materiali per la realizzazione degli strati di sacrificio per i dipinti murali staccati. Il dipinto murale, di provenienza incerta e delle dimensioni di cm. 60 di h, cm. 41.5 di larg. mm. 1-3 di sp., rappresenta una figura femminile orante che, per la resa del volto, dei particolari dell’acconciatura e la c…

MICROSCOPIC TECHNIQUES (SEM AND OM) AND ANALYTICAL APPROACH TO CHARACTERIZE CONSTITUTIVE MATERIALS AND TECHNIQUE OF THE WOODEN FRAMES IN SICILY

Nowadays artworks traditionally included in the category of applied or decorative arts are considered at the same level of fine arts getting over the old definition of minor art. According to this consideration an increasing number of studies and paper deals with the decorative arts and the Observatory for Decorative Arts in Italy “Maria Accascina” (OADI) was settled within the University of Palermo in order to study them. Nevertheless most studies deal with artistic and historic issues of applied arts and just few concern with the technique used, at least in the southern part of Italy. This paper is a systematic research concerning the constitutive materials and the executive techniques of…

Improved (photo)catalytic propene hydration in a gas/solid system by using heteropolyacid/oxide composites: Electron paramagnetic resonance, acidity, and role of water

Binary materials composed of the oxides SiO2, TiO2 and N-doped TiO2 and the Keggin heteropolyacid (PW12) were prepared and physicochemically characterized. They were used as catalysts and photocatalysts for the hydration of propene to 2-propanol. The characterization of the samples, particularly the electron paramagnetic resonance (EPR) spectroscopy results and the acidity properties, were useful to explain the key role played by the PW12 in the composite materials in the thermal and photoassisted catalytic processes. The simultaneous pres-ence of heat and UV light improved the activity of PW12 in the thermal process, and the binary materials showed better (photo)catalytic activities than t…

Il progetto "Salvalarte Respirapulito"

Electrodeposition of CeO2 and Co-Doped CeO2 Nanotubes by Cyclic Anodization in Porous Alumina Membranes

An anodic electrodeposition process is proposed to prepare CeO2 and Co-doped CeO2 nanotubes. Anodic alumina membrane is used as template and linear sweep voltammetry is employed to allow the formation of nanotubes without alumina dissolution. SEM micrographs showed large arrays of well defined and aligned NTs, which resulted to be crystalline soon after deposition according to XRD diffraction patterns and Raman Spectroscopy.

Photocatalytic conversion of glucose in aqueous suspensions of heteropolyacid-TiO2 composites.

Commercial and home prepared TiO2 samples were functionalized with a commercial Keggin heteropolyacid (HPA) H 3PW12O 40 (PW12) or with a hydrothermally home prepared K 7PW11O 39 salt (PW11). All the materials were characterized by specific surface area measurements (BET), XRD analyses, Raman, DRS along with SEM observations and they have been used for glucose photocatalytic conversion in an aqueous suspension. Different reaction extents and distribution of intermediate oxidation products were observed depending on the photocatalyst. Gluconic acid, arabinose, erythrose and formic acid were observed as oxidation products when bare TiO2 or HPA/TiO2 composite materials were used. Glucose isomer…

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…

Synthesis and characterization of zinc hydroxystannate films

Indagini non Distruttive per una Migliore Conoscenza dei Documenti dell'Archivio Storico Diocesano di Palermo

SISTEMA LEGANTE IDRAULICO PER L’EDILIZIA DA MATERIALI DI SCARTO

Catalytic Dehydration of Fructose to 5-Hydroxymethylfurfural in Aqueous Medium over Nb2O5-Based Catalysts

The catalytic dehydration of fructose to 5-hydroxymethylfurfural (HMF) in water was performed in the presence of pristine Nb2O5 and composites containing Nb and Ti, Ce or Zr oxides. In all experiments, fructose was converted to HMF using water as the solvent. The catalysts were characterized by powder X-ray diffraction, scanning electron microscopy, N2 physical adsorption, infrared and Raman spectroscopy and temperature-programmed desorption of NH3. Experimental parameters such as fructose initial concentration, volume of the reacting suspension, operation temperature, reaction time and amount of catalyst were tuned in order to optimize the catalytic reaction process. The highest selectivit…

Selective oxidation of phenol and benzoic acid in water via home-prepared TiO2 photocatalysts: Distribution of hydroxylation products

Abstract The hydroxylation of phenol (a substrate containing an electron donor group) and of benzoic acid (a substrate containing an electron withdrawing group) has been carried out by the photocatalytic method in aqueous suspensions containing commercial or home prepared TiO2 samples. The aim of the work was to study the distribution of hydroxylation products when different photocatalysts were used and to correlate the selectivity to some physico-chemical features of the powders. The samples were characterized by X-ray diffraction, thermogravimetry, determination of crystalline phase percentage, specific surface area and zero charge point. The photoreactivity results indicate that the prod…

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.

Triorganotin(IV) derivatives of 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid. Synthesis, spectroscopic characterization, in vitro antimicrobial activity and X-ray crystallography

Triorganotin(IV) complexes of the 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid (HL), Me 3 SnL(H 2 O), ( 1 ), [ n -Bu 3 SnL] 2 (H 2 O), ( 2 ), Ph 3 SnL(MeOH), ( 3 ), were synthesized by reacting the amino acid with organotin(IV) hydroxides or oxides in refluxing methanol. The complexes have been characterized by elemental analysis, 1 H, 13 C and 119 Sn NMR, IR, Raman and 119 Sn Mossbauer spectroscopic techniques. Single crystal X-ray diffraction data were obtained for compounds ( 2 ) and ( 3 ). Ph 3 SnL(MeOH) presents a trigonal bipyramidal structure with the organic groups on the equatorial plane and the axial positions occupied by a ligand molecule, coordinated …

Studio Sperimentale sulle Calci Magnesiache

INFLUENCE OF CORK POWDER GRAINSIZE IN THERMAL AND MECHANICAL PROPERTIES OF CORK-NHL MORTARS

Cork is a unique material, characterized by small closed cell structures, high insulating properties, very low density, high fire resistance and a very good durability after simple thermal treatment. The main use of cork in the production of stopper and insulating panels obtained with cork grains and a polymeric resin. Usually cork grains used in panel production have a grainsize around 1-2 mm. In this work cork grains have been used as aggregates for natural hydraulic lime mortars by reducing grainsize distribution. Cork grainsize has been reduced by means of a knife mill and divided in three different distributions, i.e. 1, 0.5 and 0.25mm. Mortars have been prepared according to NHL to co…

IL TEATRO GRECO ROMANO DI TAORMINA. Note preliminari sulla caratterizzazione di alcuni materiali

Biodeterioration of the Wooden Roof of the Phnom Penh National Museum

Within the framework of a training program in Cambodia, during a visit to the National Museum in Phnom Penh, the most important in the Kingdom of Cambodia, the authors noted the presence of some signs of a termite attack in the secondary elements of the roof of an inner garden. Following this observation, a further investigation was performed in order to evaluate the phytosanitary condition of the wooden bearing element of the roof. The inspection highlighted the presence of severe decay, constituting a real danger for the integrity of the roof; consequently, an intervention of restoration, conservation and safeguard was considered to be necessary and urgent. This paper presents the results…

Lithium silicate admixture in mortars to be used as putty for limestone

Marble is a very common material in artworks for its softness, relative isotropy and homogeneity and its characteristic waxy look that gives "life" to sculptures. Even if in geology the term "marble" refers to metamorphosed limestone, commonly the term ‘marble’ is used more broadly encompassing hard unmetamorphosed limestone that can be polished assuming a glossy aspect. In the restoration field when marble artworks have cracks that alter the smoothness of their surface, a putty is used to fill them, for both aesthetic and conservative reasons. Putties usually consist of epoxy resin mixed with marble powder. The use of a synthetic resin raises some doubts on compatibility and durability of …

Absolute crystallinity and photocatalytic activity of brookite TiO2 samples

Abstract This study reports a method to determine the absolute crystallinity of partly crystalline brookite TiO2 photocatalysts. A natural, a commercial and various home-prepared brookite powders were characterized by X-ray diffraction analysis, Raman spectroscopy, scanning electron microscopy, UV–vis diffuse reflectance spectroscopy and nitrogen adsorption measurements. The absolute crystallinity was calculated from the ratio between the full width at half maximum intensity of the (121) X-ray diffraction peaks of the brookite samples and the (111) peak of CaF2 as internal standard. The photocatalytic activity of the powders was tested employing the photodegradation of 4-nitrophenol as well…