Search results for "Position"
showing 10 items of 6771 documents
EDXRF analysis of blue pigments used in Valencian ceramics from the 14th century to modern times
2006
Abstract EDXRF analyses of cobalt-blue pigments were performed on 73 pieces of Valencian ceramics from the beginning of the 14th century up to the 20th century. In 67 of such samples, the pigment decoration was applied together with a tin opacified lead glaze cover on the clay body. In five samples the pigment was applied on the clay body without a glaze cover. The comparison between EDXRF spectra from coloured and non-coloured areas contains information about the pigment composition. Elements like Mn, Fe, Co, Ni, Cu, Zn and As are identified as characteristic of blue pigments; different associations of these elements were found and correlated with the chronology of the samples. The results…
Implications for paleomobility studies of the effects of quaternary volcanism on bioavailable strontium: a test case in North Patagonia (Argentina)
2020
Strontium isotopes (⁸⁷Sr/⁸⁶Sr) are used as geochemical tracers for paleomobility studies because they display predictable and stable patterns in ecosystems primarily controlled by the underlying geological regimes. While bedrock geology is stable over thousands of years, geomorphological processes can influence the ⁸⁷Sr/⁸⁶Sr in ecosystems over archeologically relevant timescales. Among these geomorphological processes, the deposition and reworking of volcanic sediments over Quaternary timescales are little studied but could be an important control of ⁸⁷Sr/⁸⁶Sr variations in many archeological regions. North Patagonia is a key archeological region to address animal and human movements, and a…
The “recipe” of the stucco sculptures of Giacomo Serpotta
2002
Abstract Mineralogical and chemical data (organic) of some representative samples collected from stucco-works by the famous Sicilian sculptor Giacomo Serpotta (Palermo, 1656–1732) have been combined with the aim of ascertaining their manufacture technology in the light of local historical sources. A complete correspondence between samples belonging to the “Victory” statue (1723) and the S.S. Rosario oratory (1685–1689) as regards stratigraphy, mineralogy of sand aggregate, composition of binder matrix, and nature and concentrations of organic additives is pointed out. Considering that the studied works of art cover more than 35 years of the artist’s activity, it is consequential to think of…
Preservation and decay of plant remains in two Palaeolithic sites: Abrigo de la Quebrada and Cova de les Cendres (Eastern Spain). What information ca…
2020
Abstract Plant remains are quickly affected by post-depositional processes once they are deposited in archaeological sites. In normal conditions, decomposing organisms cause their decay and final disappearance unless a preservation agent, as carbonisation or mineralisation, inhibit their activity. Moreover, physical and chemical processes could also lead to the partial or total destruction of the archaeobotanical assemblage. Thus, an analysis of their characteristics is useful for an assessing of the taphonomic processes. Archaeobotanical assemblages from two Palaeolithic sites, Abrigo de la Quebrada and Cova de les Cendres, have been analysed in terms of taxonomic composition of the assemb…
Vuoto e progetto
2018
Incentrare sul vuoto un ragionamento ampio sull’architettura apre il campo a un cammino a ritroso volto a selezionare, nel tempo lungo della formazione di chi lo compie, gli strumenti utili a riconoscere e far propria un’idea di spazio. Inteso comunemente come un’assenza, il significato di vuoto è, nelle intenzioni del testo, volutamente ribaltato. Assunto come un soggetto attivo, esso configura un intento propositivo finalizzato al posizionamento di una presenza protesa a riverberare, nell’intero organico di una composizione, una dimensione icastica. Derivata prima della nozione di spazio, il vuoto, in architettura, è dato da un’importante attribuzione di senso a un intorno definito. Al pa…
Il destino della Biblioteca pubblica e il ruolo dell’Architettura. Strategie di progettazione per gli edifici del XXI secolo
Oggi ci chiediamo spesso quale sarà la sorte del libro e delle biblioteche rispetto allo sviluppo delle tecnologie digitali e ai cambiamenti della funzione urbana e sociale delle biblioteche. Provare ad immaginare un plausibile scenario futuro é molto difficile, soprattutto se si pensa che il libro e le biblioteche sono legate a diverse e diversificate istanze della società contemporanea che non hanno ancora trovato una propria identità. D’altra parte, la società contemporanea si trova in una fase di transizione tecnologica che rischia, senza alcun dubbio, di produrre dei cambiamenti significativi, non solo in seno alle biblioteche, ma soprattutto nei nostri stessi modi di vivere. Per quest…
SINGLE-PEAK RESOLUTION CRITERIA FOR OPTIMIZATION OF MOBILE PHASE COMPOSITION IN LIQUID CHROMATOGRAPHY
2001
Three criteria that evaluate the single peak resolution (peak purity) in chromatography, the free height fraction, free area fraction, and valley ratio, are examined. The main advantages of these criteria against other criteria based on peak pair separation, are that the measurements are not affected by the identity of neighboring peaks and are normalized, which make them very intuitive. The methodology is illustrated through the isocratic separation of mixtures of several sulphonamides (sulphacetamide, sulphadiazine, sulphadimethoxine, sulphaguanidine, sulphamerazine, sulphamethazine, sulphamethoxazole, sulphamethizole, sulphamonomethoxine, sulphanilamide, sulphapyridine, sulphaquinoxaline…
Area‐Selective Atomic Layer Deposition on Functionalized Graphene Prepared by Reversible Laser Oxidation
2022
Publisher Copyright: © 2022 The Authors. Advanced Materials Interfaces published by Wiley-VCH GmbH. Area-selective atomic layer deposition (ALD) is a promising “bottom-up” alternative to current nanopatterning techniques. While it has been successfully implemented in traditional microelectronic processes, selective nucleation of ALD on 2D materials has so far remained an unsolved challenge. In this article, a precise control of the selective deposition of ZnO on graphene at low temperatures (<250 °C) is demonstrated. Maskless femtosecond laser writing is used to locally activate predefined surface areas (down to 300 nm) by functionalizing graphene to achieve excellent ALD selectivity (up to…
TP53 codon 72 polymorphism and cervical cancer
2009
Background Cervical cancer is caused primarily by human papillomaviruses (HPV). The polymorphism rs1042522 at codon 72 of the TP53 tumour-suppressor gene has been investigated as a genetic cofactor. More than 80 studies were done between 1998 and 2006, after it was initially reported that women who are homozygous for the arginine allele had a risk for cervical cancer seven times higher than women who were heterozygous for the allele. However, results have been inconsistent. Here we analyse pooled data from 49 studies to determine whether there is an association between TP53 codon 72 polymorphism and cervical cancer.Methods Individual data on 7946 cases and 7888 controls from 49 different st…
<title>Electrochromism in oxyfluoride thin films</title>
1994
Oxyfluoride films based on W and Ti were prepared by reactive sputtering in plasmas containing O2 + CF4. The deposition rate was large, particularly when chemical sputtering was promoted by heating the target. The films could show large charge insertion/extraction, high coloration efficiency, and good cycling durability.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.