Search results for "Ceramic"

Archaeometric analysis of building ceramics and ‘dolia defossa’ from the Roman Imperial estate of Vagnari (Gravina in Puglia, Italy)

2021

Abstract This paper concerns the archaeometric analysis of ceramic finds dating to the Roman Imperial period, brought to light during the excavation campaigns conducted at Vagnari (Puglia) in south-east Italy. On the site of the central village (vicus) of this imperial estate, established by the Roman Emperor in the early 1st century CE, large dolia (wine vats) sunk into the floor of a winery of the 2nd century CE recently were brought to light. Other discoveries include kilns for the production of ceramic roof tiles and also kiln wasters such as misfired tiles. The purpose of the analytical approach was therefore twofold: 1) to establish the composition of local ceramic products and of raw…

Investigation on four centuripe vases (late 3rd-2nd cent. B.C.) by portable X-ray fluorescence and total reflectance-FTIR

2021

Abstract Four Centuripe vases dated back to the late 3rd-2nd centuries B.C. were analysed using imaging under visible and ultra-violet illumination as well as complementary non-invasive and non-destructive portable X-Ray Fluorescence (XRF) and Total Reflectance – Fourier Transform InfraRed (TR-FTIR) spectroscopies. The vases are of great importance since they represent a rare expression of the Hellenistic vase painting. Four specimens, a “pyxis”, a “lebes gamikos” and two “lekanides” decorated with figures of different type, are exhibited in the Antonino Salinas Archaeological Museum in Palermo-Italy. The investigation was aimed to identify the used pigments and the painting technique, to r…

Le ricerche archeometriche: la caratterizzazione delle produzioni di anfore punico-siciliane

2016

La definizione archeologica ed archeometrica delle produzioni della Sicilia punica ha costituito una delle priorità nell’ambito di un progetto di ricerca incentrato sulla provenienza di anfore commerciali da siti del Mediterraneo centro-meridionale. Presentiamo qui la versione aggiornata ed ampliata, in lingua italiana, di questo studio, parzialmente già pubblicato nella quarta edizione della banca dati di FACEM. L’analisi delle serie di anfore punico-siciliane ha avuto due obiettivi di base: 1. definire il repertorio tipologico delle singole città, già ben conosciuto per le fondazioni fenicie di Motya (cap. 6) e Solus (cap. 4), meno chiaro quello di Panormos (cap. 5) e sostanzialmente anco…

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 …

Clayey materials used for ceramic manufacture in ancient Sicily

2009

Efficient ultraviolet-light energy dissipation by an aromatic ketone.

2010

Experimental evidence on the efficiency of 2,2'4,4'-tetramethoxybenzil for UV-light energy dissipation is provided. This non-phenolic aromatic ketone has a low energy triplet which quickly decays to the ketone ground state, thus avoiding the generation of undesirable reactive species. El Moncef, Abdelkarim, elmonab@alumni.uv.es ; Cuquerella Alabort, Maria Consuelo, Chelo.Cuquerella@uv.es ; Zaballos Garcia, Elena, Elena.Zaballos@uv.es ; Ramirez de Arellano Sanchez, Maria del Carmen, Carmen.Ramirezdearellano@uv.es ; Stiriba, Salah Eddine, Salah.Stiriba@uv.es ; Perez Prieto, Julia, Julia.Perez@uv.es

Broadband dielectric spectroscopy of 0.4PMN-0.3PSN-0.3PZN ceramics

2007

In this paper, results of the broadband dielectric spectroscopy of 0.4PbMg1/3Nb2/3O3-0.3PbZn1/3Nb2/3O3-0.3PbSc1/2Nb1/2O3(0.4PMN-0.3PZN-0.3PSN) are presented. Dielectric spectra of these solutions were investigated in a broad frequency range from 20 Hz to 100 GHz. Very strong and broad dielectric relaxation was analyzed in terms of distribution of relaxations times, using Tichonov regularization method. It revealed slowing down of the longest relaxation and the mean relaxation times in the agreement with the Vogel-Fulcher law and the Arrhenius law, respectively.

Modeling of Point Defects in Corundum Crystals

1994

Several different approaches including Hartree-Fock ab initio cluster calculations, semiempirical INDO calculations, and atom-atom potentials were used for modeling of the spatial and electronic structure as well as migration mechanisms of both intrinsic defects (self-trapped and defect-trapped holes, O and Al vacancies) and impurities (transition-metal ions like Co, Fe, Mg, Mn, Ti). The atomic structure of all hole centers is found to be similar to V[sub K] centers in alkali halides (two-site model); their formation is energetically favorable. The energy required for 60[degree] hole reorientations inside the basic oxygen triangles is found to be similar to both the energy for hops between …

Dipolar and orientational glass formation in two-dimensional films of CO mixtures

2002

Heat-capacity and dielectric measurements have been performed to study orientational and dipolar order and disorder phenomena in submonolayer films of CO and binary mixtures of CO physisorbed on graphite and boron nitride (BN). With both methods transitions to quadrupolar and dipolar ordered low-temperature phases have been found for pure CO. Calorimetric measurements revealed that the dipolar transition of CO on graphite belongs to the universality class of the two-dimensional (2D) Ising model. It will be shown that in dilute mixtures of CO with CH 4 molecules a dramatic suppression of this phase transition occurs. This effect turned out to be much stronger than that previously observed in…

The effects of Pr3+ doping on the dielectric and photoluminescence properties of BaTi0.9(Yb0.5Nb0.5)0.1O3 ceramic

2019

Abstract The praseodymium Pr3+ doped BaTi0.9(Yb0.5Nb0.5)0.1O3 (BTYN01) ceramic, under low concentration (0.1%), was prepared by a conventional ceramic fabrication technique and its phase structure, microstructure, dielectric, vibrational and photoluminescence (PL) properties was studied. Both X-ray diffraction (XRD) and Raman studies confirmed the incorporation of Pr3+ into A-site lattice of BTYN01. The structure of Ba0.9985Pr0.001□0.0005Ti0.9(Yb0.5Nb0.5)0.1O3 (BTYN01-Pr) shows the coexistence of Pm 3 ¯ m -cubic symmetry (∼10%) and P4mm-tetragonal symmetry (∼90%) at room temperature. The dielectric study reveals that the maximum of the dielectric constant of BTYN01-Pr occurred at 283 K. The…