42,390 research outputs found
In-plane behaviour of NFRCM-strengthened masonry modelled by means of discrete elements
No full textIn the last years, the attention to the use of eco-compatible materials and the development of sustainable solutions for structural strengthening has increased, leading to fibre-reinforced cementitious matrices (FRCM) made by natural fibres (NFRCM, de Carvalho et al. 2017).
NFRCM strengthening systems, in the same manner as FRCM ones, can be considered an alternative to fibre-reinforced-polymer (FRP) reinforcement for masonry structures, to improve the compatibility of reinforcement applied to masonry substrate (di Tommaso et al. 2017).
The numerical assessment of NFRCM and/or FRCM strengthened masonry is an active field of research and it represents a complex task, due to the complexity of both reinforcement and support materials, which can be considered as composite ones. In literature, some macro-models consider both masonry components (bricks and mortar) as a homogeneous continuum, and FRCM layers are considered as an additional equivalent continuum, with the textile fibres assumed as an embedded reinforcement of mortar matrix (Wang et al. 2017). These models have been extended to NFRCM (de Carvalho et al. 2019).
Recently, a simplified micro-model approach was proposed for diagonally loaded masonry panels reinforced with FRCM (Murgo et al. 2021), adopting a 2D FE model with one-dimensional interfaces for masonry panels, and adding a bi-directional grid of trusses for representing the reinforcement.
An updated discrete element model for simulating the in-plane behaviour of masonry walls strengthened with FRCM or NFRCM has been recently introduced by authors (Baraldi et al. 2021). This model is based on an existing discrete or rigid block model having rigid elements and nonlinear one-dimensional interfaces between them, able to represent both mortar joints and brick cracking (Baraldi et al. 2020). Such a model has been improved by considering masonry strengthened on both sides The hypothesis of perfect adhesion between the wall and reinforcement and also between the matrix and fibres of the strengthening system is assumed, in order to avoid the increase of model degrees of freedom with respect to the unreinforced masonry (URM) case. The reinforcement is modelled by means of further stiffness and strength parameters accounting for the FRCM/NFRCM geometrical and mechanical properties.
The proposed model has already turned out to successfully simulate cracking both on masonry and the external reinforcing layers and it was calibrated with respect to an existing simplified numerical model (de Carvalho et al. 2019).
In this work, the proposed discrete model is calibrated and compared with respect to several existing laboratory tests of in-plane loaded masonry panels reinforced with FRCM and NFRCM layers, in order to highlight its effectiveness and potential improvements
Phoenicians preferred red pigments: micro-Raman investigation on some cosmetics found in Sicily archaeological sites
No full textThis research was undertaken in the aim of identifying and getting deeper knoowledge into materials and pigments used in cosmestics concerning the contest of the phoenician settlements in Sicilian territory. In fact, about the typologies of cosmetics in use among the Phoenicians, little is known. On this subject, generally references come from bibliographic latin sources: in antiquity, women preferred to paint white their face, red lips and cheeks, yellowish eyes and black to sorround their look (Pliny the Elder, Naturalis Historia; Ovidius, De medicamine faciei feminae). An interesting aspect of this research is that just one paper is known on Punic cosmetics.[1]
In the Museo Archeologico Regionale “Antonino Salinas” (Palermo, Sicily) an important collection of unguentaries coming from the town of Selinunte is preserved. Some of them, finely crafted, come from the sanctuary of Demetra Malophoros, some unguentaries come from the acropolis and some more from the necropolis (dating from the 6th to the 5th century b. C). The sacred area, excavated by Cavallari (1818) and Salinas (1903-1905), have provided a great amount of archaeological materials. In the area where once the acropolis rose, the remains show a mixed village, Phoenician and Greek. In this study, the findings from Salinas were considered, as well as some others from the Museum Conte Agostino Pepoli (Trapani), from the Museum Baglio Anselmi (Marsala) and from the museum of Mozia. The number of glass and fictile unguentaries, pyxis and alabastra examined were large: 142 items from Salinas, 210 from Mozia, 14 from Pepoli and 117 from Baglio Anselmi.
This research has completed the one carried out on 210 samples from the Museum of Whitaker Foundation from Mozia, a merely phoenician –punic settlement.[2,3]
The samples were analyzed by spectroscopic techniques.
The IR spectra were acquired with a spectrophotometer VERTEX 70 (Bruker) FT-IR, equipped with a detector deuterium triglycine sulphate (DTGS). The setting parameters were: resolution 4 cm-1, spectral range 4000-600 cm-1, number of scans 32. ATR spectra were recorded using an Elmer Golden-Gate accessory.
The micro-Raman spectrometer used in this case was a Labram Model from the Jobin Yvon-Horiba with a spatial resolution of 1 μm and with quick detection ability as a result of the CCD detector 1024x256 pixels cooled to -70°C by the Peltier effect. The spectral resolution was 1 cm-1. The exciting wavelength was the 632.8 nm red line of a He-Ne laser.
Generally the samples were presented as inorganic powders of different colors: white, black, blue and red. Though the samples came from different museums, they were considered togheter, since they belonged all to the Phoenician culture and coming from Trapani archaeological sites.
The white samples were of two types. The first one was mainly composed of gypsum and anhydrite mixtures (e.g. Inv No 1680, 1663, 1753); the other type (e.g. pyxes Inv N° 1393, 1451) was composed of fully carbonated cerussite, gypsum and litharge. The second kind of cosmetic corresponded to the most famous Greek cosmetic, called psymition, used by women to white the skin. The first type suggested that, for the same use, alternative materials, cheaper and most readily available, could be employed in the past.
The black powders, usually used to outline the eyes, were mostly given by carbon obtained from vegetable combustion (e.g. Inv. N° 1566, 2314, 4313) or, sometimes, from bone combustion (animal charcoal) as for the samples Inv. N° 3140, 1761.
A single blue powder (Inv N° 42259) was consisted by the famous Egyptian blue (CaCuSi4O10).
The love for the red color by Phoenician is evident from the great number of powders of this color, probably used to give color to the cheeks or lips. A wide variety of red minerals was found. In many cases the presence of hematite (e.g. Inv N° 2309, 2689, 4269) was detected.
A large number of pink and red powders containing cinnabar (unguentaries Inv N° 1393, 6480-1, 34396) was observed. No frequent and very interesting is in fact the HgS finding powder into alabastra (e.g. Inv. N° 7317/7, 1255), a holder typically used to contain ointments.
Another red pigment was identified as red lead (e.g. Inv N° 1606).
Finally, a singular discovery was the presence of red lead chromates chrocoite and phoenicochroite, two very rare minerals (e.g. sample Inv. N° 805, 1-98-2, 4386). In fact, they have never been previously attested for cosmetic use, and also rarely attested in paintings before the end of the 18th century when it began to be produced industrially.[4]
The high number of Phoenicians samples taken into examination has allowed to understand the typology of raw materials used by the Phoenicians settled in Sicilian contexts.
In this study affects the materials heterogeneity used for the make-up, even for example in comparison to the Roman culture, for which there has come a greater number of samples (sites such as Pompeii, Herculaneum and Oplontis were analyzed by our research group),[5-7] but which revealed a palette less extensive and less refined. In particular, this study identified the use of many kind of red pigments, also very rareof mineral origin.
References
[1] A. Huqet al., Combined, Appl. Phys. A, 2006, 83, 253–256.
[2] G. Freguglia, C. Baraldi, M.C. Gamberini, P. Toti, P. Baraldi, PRIN07- Colors and balms in antiquity: from the chemical study to the knowledge of technologies in cosmetics, painting and medicine. Aboca, Sansepolcro (Arezzo, Italy), 2-3th December 2010, p. 50-51.
[3] C. Baraldi, G. Freguglia, M.C. Gamberini, P. Baraldi, 5-8th September 2011, RAA2011, Parma, 2011, p. 103-104.
[4] R.J.H. Clark. Chimie, 2002, 5, 7–20.
[5] P. Baraldi, C. Fagnano, C. Baraldi, M.C. Gamberini, Automata, 2006, 1, 49.
[6] M.C.Gamberini, C. Baraldi, F. Palazzoli, E. Ribechini, P. Baraldi, Vib. Spectrosc. 2008, 47/2, 82.
[7] E. Van Elslande, M.C. Gamberini, C. Baraldi and P. Walter, An overview of the Raman studies on cosmetic powders from Pompeii, 14-18th September 2009. RAA2009, Bilbao, 2009
A MicroRaman study of some paintings from Tassili (Sahara)
No full textSome investigations on the composition of the powders found in the Egypt desert and used as pigment
Analisi micro-Raman di polveri cosmetiche greche e puniche
No full textPresso il Museo Archeologico Regionale “Antonino Salinas” di Palermo è conservato un importante nucleo di balsamari provenienti da Selinunte. Taluni, di pregevole manifattura, provengono dal Santuario di Demetra Malophoros. Altri unguentari e balsamari provengono dall’acropoli, altri ancora dalle necropoli. Appartengono ad un periodo compreso tra la metà del VI e la metà del V secolo a. C. L’area sacra, messa in luce durante gli scavi effettuati da Cavallari nel 1818 e da Salinas nel 1903-1905, ha portato alla luce una quantità immensa di materiali archeologici. Nell'area dove prima sorgeva l'acropoli i resti presentano un abitato misto, punico e greco. Al fine di questo studio sono stati inoltre presi in esame anche altri campioni, conservati nei saloni espositivi e in magazzino, provenienti dall’isola di Mozia, insediamento prettamente fenicio-punico.Gli insediamenti da cui provengono i contenitori, Selinunte e Mozia, offrono una gamma di valenze culturali assai variegata che sta a confermare il loro carattere di insediamenti nati da e per lo scambio. Le analisi condotte nel presente lavoro fanno seguito a quelle relative ad un importante gruppo di contenitori cosmetici di età Punica, coevi a quelli qui studiati, conservati presso il Museo della Fondazione Withaker sull’isola di Mozia [1,2].Il nucleo di balsamari fittili e vitrei, pissidi e alabastra considerati è stato ispezionato e si sono raccolte polveri di vari colori.La microscopia Raman ha permesso di identificare e caratterizzare i residui. Campioni bianchi hanno rivelato essere composti prevalentemente da miscele di gesso e anidrite (n inv. 1680, 1663, 1753). Le pissidi n. 1393 e 1451 presentavano residui bianchi composti da cerussite completamente carbonatata, gesso e litargirio. Si tratta del cosmetico greco per eccellenza, denominato psymition, utilizzato dalle donne per conferire pallore all’incarnato.Polveri rosa contenute in balsamari figurati di origine greca hanno mostrato come componenti ematite, quarzo, calcite, anatasio e goetite oppure, nel caso dell’askos zoomorfo n. 610, calcite, ossido di piombo, ematite, carbone e residuo organico. Il contenitore in vetro policromo n. 34228 presentava un abbondante residuo rosso composto da magnetite, quarzo, silicati ed ematite. Una conchiglia del genere Pecten (n. 34396) mostrava residui rossi composti da ematite, magnetite, lepidocrocite, goetite e tracce di cinabro (HgS). Un’interessante polvere rossa, (HgS miscelato con anatasio) è stata rinvenuta all’interno dell’ alabstron n. 7317/7 proveniente dalla necropoli di Marsala (tomba n.34). Risultati simili si sono ottenuti nell’ambito delle precedenti indagini su Mozia relative a contenitori della stessa tipologia. Il rinvenimento di questi pigmenti in associazione ad alasbatra è interessante in quanto la letteratura generalmente indica l’uso dedicato di questi particolari contenitori ad unguenti e profumi. Le analisi del contenuto azzurro della coppetta fittile n. 42259 hanno rilevato la presenza del celebre blu egiziano (CaCuSi4O10).Bibliografia[1] G. Freguglia, C. Baraldi, M.C. Gamberini, P. Toti, P. Baraldi,; PRIN07- Colors and balms in antiquity: from the chemical study to the knowledge of technologies in cosmetics, painting and medicine. Aboca, Sansepolcro (Arezzo, Italy), 2-3th December 2010, p. 50-51[2] C. Baraldi, G. Freguglia, M.C. Gamberini, P. Baraldi, RAA2011 Parma 5-8th September 2011, pp. 103-104
Indagine sui recipienti con pigmenti da domus pompeiane
No full textNegli ultimi 250 anni di scavi eseguiti nei siti di Pompei ed Ercolano sono stati rinvenuti numerosi pigmenti che sono serviti a dipingere e adornare le numerose ville alle falde del Vesuvio. Tali colori sono arrivati a noi, spesso, accuratamente conservati in ciotole, vasi, balsamari e altri piccoli contenitori fittili, in vetro e bronzo trovati all'interno di botteghe e abitazioni. Secondo il"Giornale degli Scavi di Pompei" della Soprintendenza Archeologica di Pompei, il primo scavo nella Regio l, lnsula 9 (l 9, 9) ebbe luogo nel 1952. Vicino agli scheletri di quattro individui, vennero trovate circa 150 ciotole globulari, fritilla e olle. La presenza di materiale all'interno costituisce un'opportunità per la ricostruzione della storia e delle tecniche pittoriche di Pompei e del mondo romano.
Sui contenuti sono stati applicati metodi molecolari di analisi, quali spettroscopia FT-lR e microscopia Raman, per l'identificazione della composizione. I risultati ottenuti consentono alcune considerazioni. Molti componenti quali quarzo, calcite, feldspati, diopside e pirite sono riferibili all'intonaco o ai prodotti dell'eruzione. L'aragonite presente massivamente puo' derivare da minerali bianchi, ma più probabilmente può essere dovuta alla macinazione di valve di molluschi. Ciò è importante per la comprensione dei decori bianchi su fondo colorato dei dipinti murali romani. ll pigmento blu è sempre a base di blu egiziano, mentre il verde può essere ottenuto mescolando un giallo e un blu; più frequentemente il verde è accertato come miscela di terra verde e blu egiziano. Malachite e azzurrile si ritrovano come prodotti di degrado di leghe metalliche a base di rame. Altri rari casi sono la cuprite, derivante da alterazione del rame e il litargirio, dall'alterazione di cerussite o piombo. La cerussite, identificata in alcuni contenitori, non è un pigmento per pitture murali: è noto da Plinio e da altri autori il suo uso come fondotinta, e questo può essere una prova della preparazione in I 9, 9 anche di contenitori per cosmetici
Binding of the radioligand [3H]-SCH 58261, a new non-xanthine A2A adenosine receptor antagonist, to rat striatal membranes
No full textThe present study describes the binding to rat striatal A2A adenosine receptors of the new potent and selective antagonist radioligand, [3H]-5-amino-7-(2-phenylethyl)-2-(2-furyl)-pyrazolo[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidine, [3H]-SCH 58261. [3H]-SCH 58261 specific binding to rat striatal membranes (>90%) was saturable, reversible and dependent upon protein concn. Satn. expts. revealed that [3H]-SCH 58261 labeled a single class of recognition sites with high affinity (Kd = 0.70 nM) and limited capacity (apparent Bmax = 971 fmol mg-1 of protein). The presence of 100 μM GTP in the incubation mixt. did not modify [3H]-SCH 58261 binding parameters. Competition expts. showed that [3H]-SCH 58261 binding is consistent with the labeling of A2A striatal receptors. Adenosine receptor agonists competed with the binding of 0.2 nM [3H]-SCH 58261 with the following order of potency: 2-hexynyl-5'-ethylcarboxamidoadenosine (2HE-NECA)>5'-N-ethylcarboxamidoadenosine (NECA)>2-[4-(2-carboxyethyl)phenethylamino]-5'-N-ethylcarboxamidoadenosine (CGS 21680)>2-phenylaminoadenosine (CV 1808)>R-N6-phenylisopropyladenosine (R-PIA)>N6-cyclohexyladenosine (CCPA)>S-N6-phenylisopropyladenosine (S-PIA). Adenosine antagonists inhibited [3H]-SCH 58261 binding in the following order: 5-amino-9-chloro-2-(furyl)-[1,2,4]-triazolo[1,5-c]quinazoline (CGS 15943)>5-amino-8-(4-fluorobenzyl)-2-(2-furyl)pyrazolo[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidine (8FB-PTP)=SCH 58261>xanthine amine congener (XAC)=(E,18%-Z,82%)7-methyl-8-(3,4-dimethoxystyryl)-1,3-dipropylxanthine (KF 17837S)>8-cyclopentyl-1,3-dipropylxanthine (DPCPX)≥8-phenyltheophylline (8-PT). The Ki values for adenosine antagonists were similar to those labeled with the A2A agonist [3H]-CGS 21680. Affinities of agonists were generally lower. The A1-selective agonist, R-PIA, was found to be about 9 fold more potent than its stereoisomer, S-PIA, thus showing the stereoselectivity of [3H]-SCH 58261 binding. Except for 8-PT, the adenosine agonists and antagonists examd. inhibited [3H]-SCH 58261 binding with Hill coeffs. not significantly different from unity. The present results indicate that [3H]-SCH 58261 is the first non-xanthine adenosine antagonist radioligand which directly labels A2A striatal receptors. High receptor affinity, good selectivity and very low non-specific binding make [3H]-SCH 58261 an excellent probe for studying the A2A adenosine receptor subtype in mammalian brain
I codici purpurei: dal mito alla scienza
No full textI codici purpurei sono tra le realizzazione librarie più importanti e prestigiose dell’epoca tardoantica e medievale. Si tratta di testi delle Sacre Scritture scritti con inchiostro dorato o argentato su pergamena tinta in colore porpora. Secondo tradizione, il colore della pergamena era ottenuto immergendo il foglio in un bagno di tintura contenente la celeberrima porpora di Tiro. Dal punto di vista materiale, tuttavia, ben poco si sa delle sostanze realmente impiegate nella manifattura di questi manoscritti. Le informazioni di cui si dispone attualmente sono limitate alla trattatistica con poche evidenze diagnostiche, che peraltro non hanno confermato in alcun caso la presenza della porpora di Tiro. È evidente quindi la necessità di disporre di informazioni più numerose ed esaurienti per verificare ciò che ci proviene esclusivamente dalla tradizione letteraria. Nel presente studio sono illustrati risultati preliminari provenienti da indagini non invasive su codici purpurei del VI secolo: il Vienna Genesis (Vienna, Österreichische Nationalbibliothek), l’Evangeliario di Sarezzano (Tortona, Archivio Diocesano) e il Codice di Brescia (Brescia, Biblioteca Queriniana). Le analisi sono state effettuate mediante spettrometria XRF e spettrofotometria FORS e suggeriscono l’ipotesi che l’impiego della porpora di Tiro fosse parziale, ovvero in miscela con altri coloranti, tra cui il tornasole. I risultati andranno confrontati con altri codici coevi che saranno analizzati nel seguito del progetto
Long-term survival in myocardial infarct. Analysis of the post-infarct course in relation to the clinical aspects of the acute phase
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