Search results for " xrd"

Ethnoarchaeometric Study of the Traditional Cooking Ware Production Centre of Pabillonis (Sardinia): Investigating Raw Materials and Final Products

2010

Ethnoarchaeometry can be used to test assumptions in ceramic provenance studies. Within the Late Roman Cooking Wares (LRCW’s) commercialised in the Western Mediterranean some fabrics such as Fabrics 1.2, 1.6/1.7 and 1.9 (Fulford and Peacock, 1984) have been proposed to have a Sardinian origin. This motivated a specific project to explore the nature of cooking pottery on the island and the raw clays as well as the production technologies that have been used traditionally for their manufacture. In this paper, the traditional cooking pottery making in Pabillonis (Oristano province) was studied. First, a field survey in the area of Pabillonis was undertaken in order to locate the raw materials …

Characterization of prehispanic cosmetics found in a burial of the ancient city of Teotihuacan (Mexico)

2012

The present paper reports the chemical data obtained on samples of pigmenting materials contained in 31 miniature vessels found in a burial found in Teopancazco, a multiethnic neighborhood center located in the southeastern sector of the archaeological site of Teotihuacan (Central Mexico) and the analytical protocol established for the complete characterization of these archaeological materials. For this purpose a multi-technique approach based on the combination of several non destructive and micro-destructive instrumental techniques, namely, light microscopy (LM), scanning electron microscopy-X-ray micro-analysis (SEMe EDX), transmission electron microscopy (TEM), voltammetry of micropart…

Local environment of Barium, Cerium and Yttrium in BaCe1−xYxO3−δ ceramic protonic conductors

2007

Abstract Y-doped barium cerate protonic conductors with composition BaCe 1 −  x Y x O 3 −  δ ( x  = 0.02, 0.1, 0.2, 0.3) have been synthesized by sol–gel route, giving by X-ray diffraction tests a homogeneous crystalline phase. A commercial sample BaCe 0.8 Y 0.2 O 3 −  δ produced by combustion spray pyrolysis was also provided for comparison aim. The local structure around the cations was studied by X-ray absorption spectroscopy at the K-edges of Ba, Ce and Y. It is demonstrated that the insertion of yttrium in the site of cerium produces a remarkable local distortion of the dopant first-shell octahedral environment that affects also the next coordination shells by a static disorder increas…

Burial and thermal evolution of the Sicilian fold-and-thrust belt: preliminary results from the Scillato wedge top basin (central-northern Sicily, It…

2016

Wedge top basins are key elements for unravelling the tectonic evolution of fold-and-thrust belts. In detail, their thermal signature and sedimentary fill records modes and time of exhumation of their edges. The Scillato basin is a wedge-top basin located in the central-northern sector of the Sicilian fold-and-thrust belt (western sector of the Madonie Mts). Upper Serravallian-upper Tortonian succession composed by up to 1,200 m thick delta-river to open marine siliciclastic sediments, fills the basin. This succession lies on a deformed substrate made up of thrust sheets composed of Numidian Flysch, Sicilidi and Imerese units stacked with a SW tectonic transport. The basin fill records a po…

Oxidative dehydrogenation of ethane over NiO–CeO2 mixed oxides catalysts

2012

[EN] In this paper we present the synthesis, characterization and catalytic behaviour in the oxidative dehydrogenation of ethane of NiO-CeO2 mixed oxides. The addition of cerium oxide to NiO strongly modifies its catalytic performance, although the changes in the catalytic behaviour depend on the catalyst composition. The incorporation of low amounts of cerium oxide to NiO multiplies the productivity to ethylene in the oxidative dehydrogenation of ethane by a factor of ca. 7, which is the result of an increase in both catalytic activity and selectivity to ethylene. The enhanced activity has been related to the remarkable increase of the surface area of catalyst and the low crystal sizes of …

Colour Specification of Terracotta Calatina Specimens

2012

Role of ZrO2 addition on the formation and stabilisation of anatase catalyst: XRD, SAXS and TEM investigation

2012

Structure and oxide ion conductivity: local order, defect interactions and grain boundary effects in acceptor-doped ceria

2014

The long-range and short-range structure of nanocrystalline and microcrystalline acceptor-doped ceria is investigated by a combined approach using EXAFS, XANES, Raman, and XRD, and correlated with the oxide-ion conductivity in the bulk and in grain boundaries. Compared to Yb3+ and Er3+, the positive influence of Sm3+ is attributed to the ability to repel oxygen vacancies, and to keep a localized disorder around the dopant. The long-range structural analysis shows lattice contraction for Yb- and Er-doping and lattice expansion for Sm-doping. The short-range analysis around the dopants and cerium highlights that a more complex structural rearrangement has to be assumed to explain the compleme…

Mortars and Plasters under the Mosaics and the Wall Paintings of the Roman Villa at Piazza Armerina, Sicily

2010

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 …

Pt(II) complex @mesoporous silica: preparation, characterization and study of release

2016

Cisplatin analogs, having cytotoxic activity higher than that exerted by cisplatin, have recently triggered considerable interest by the community. The cis-[PtCl2(DMSO)HL]·2DMSO, where HL = 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid, has shown a potent cytotoxic activity on HepG2 hepatocarcinoma cells, while under identical conditions, it did not affect normal immortalized human liver cells (Chang). In this work, the above complex has been incorporated into MCM41 mesoporous silica, pure and functionalized with amino group, which is considered one of the best host for a drug delivery system for carrying high dosages of a variety of drugs in their mesopores. Sinc…