Search results for "UART"
showing 10 items of 887 documents
Study of the Chemical Conversion of Aluminum Alloys by Coupling CFDE and EQCM
2004
The ability of the channel flow double electrode (CFDE) technique and electrochemical quartz crystal microbalance (EQCM) for studying in situ chromate phosphate conversion coating on 5182 aluminum alloys was explored. It was first demonstrated that aqueous Cr(VI) can be analyzed quantitatively with the CFDE technique by reduction into Cr(III) on a graphite electrode. Samples used for EQCM were quartz plated by physical vapor deposition using a 5182 alloy target, allowing thin layers of aluminum alloys with a similar chemical composition to be obtained. EQCM was adapted in order to account for the hydrodynamic conditions in an industrial process, by placing the quartz in a flow cell. In orde…
In-situ characterisation of organosilane films formation on aluminium alloys by electrochemical quartz crystal microbalance and in-situ ellipsometry
2005
Abstract Organosilane pre-treatments have been studied intensively during the last years in order to replace hexavalent chromium conversion treatments. The aim of this study is to follow in-situ the formation of this organosilane layer in solution. Two in-situ techniques, spectroscopic ellipsometry and electrochemical quartz crystal microbalance, were used to investigate the mechanism and the kinetics of this protective film formation. In-situ measurements highlight that the organosilane film observed after the drying process is not formed into the solution, but during the emersion and drying step. Hence, it has been possible to characterise the presence of a very thin organosilane layer in…
Solubilization control by redox-switching of polysoaps
2008
Reversible changes in the self-organization of polysoaps may be induced by controlling their charge numbers via covalently bound redox moieties. This is illustrated with two viologen polysoaps, which in response to an electrochemical stimulus, change their solubility and aggregation in water, leading from homogeneously dissolved and aggregated molecules to collapsed ones and vice verse. Using the electrochemical quartz crystal microbalance (EQCM), it could be shown that the reversibility of this process is better than 95% in 16 cycles.
Platería morisca de obra de hilo (siglo XVI)
2019
The article discusses twenty tests performed by Valencian artisans to become masters of ―wire work‖ between the years 1508 and 1538. Considered minor works in the area of silver smithery, these pieces of jewellery are characterized by superimposed wire decoration. A peculiarity of these tests was that the pieces were not drawn on paper (the common practice for record-keeping purposes), but rather blackened and then stamped on- to paper. As a result, life-size and dated imprints have been preserved. as have the names of the artisans. They were silver workers whose biographies are known, all of them Christian; many of them worked in the Tossal district of Valencia, next to the M usli…
An approach to lithic raw material procurement at the middle Palaeolithic site Abrigo de la Quebrada (Chelva, Valencia)
2011
We offer a preliminary characterisation of the lithic raw-materials found in levels I-III of the Middle Paleolithic site of Abrigo de la Quebrada. The artifacts were excavated in the field seasons of 2004 and 2007, have already been the object of a preliminary technological assessment (Villaverde et al. 2008), and their analysis has been preceded by a survey of local procurement sources, carried out in 2008. We present, in a regional context, the different raw-material categories recognized (by means of a macroscopic study), and variants thereof, and we describe the different outcrops identified. Based on these data, we attempt a preliminary assessment of the resource catchments and mobilit…
Alternative chronologies for Late Quaternary (Last Interglacial–Holocene) deep sea sediments via optical dating of silt-sized quartz
2003
Abstract We summarize the results of a test on the potential of optical dating for the age assessment of Late Quaternary deep-sea sediments. Our approach combines a single aliquot regeneration (SAR) protocol for equivalent dose ( D e ) estimation on fine silt-sized quartz with a time-dependent evaluation of supported and unsupported long-lived radioisotopes within the deposited sediment matrix. For this purpose nine samples from two independently dated deep-sea cores from the Indian Ocean were obtained. The SAR analysis resulted in mean D e estimates with precisions ranging from 0.9% to 3.7%. Combination of these data with measured radioisotope concentrations resulted in stratigraphically s…
The ‘grave of the Court Pit’, A rediscovered Bronze Age tomb from Carchemish
2014
This paper examines the British Museum unpublished records related to an Early Bronze (EB) Age pithos burial uncovered a century ago in the Inner Town at Carchemish. The grave, cursorily cited and variously dated (Chalcolithic, EB or even LBA) in the final reports, was described in some detail by Hogarth and Thompson; a precise dating is, however, possible today thanks to the information of paramount importance given by T. E. Lawrence who identified and took a picture of the associated finds, which was recently rediscovered in the Carchemish Archives. The pithos can be now ascribed to the third quarter of the third millennium BC and helps to confirm the recent theory according to which the …
Ceramic production at Selinunte (Sicily) during the 4th and 3rd century BCE: New archaeometric data through the analysis of kiln wastes
2018
Abstract A set of 37 overfired ceramic samples was collected from the dump of two kilns sited in the productive area FF1 in the acropolis of Selinunte (south western Sicily), being specifically active in the period 409–250 BCE. The ceramic samples were analysed by thin-section petrography and chemical analysis, with the aim to establish a valuable ‘reference group’ representative of the ceramic produced at Selinunte during the Punic phase. The petrographic and chemical analyses allowed to state that the ceramic manufactures from the kilns operating in the FF1 insula are characterized by rather homogeneous textural/compositional features. The daily-use common ware here produced is characteri…
From sepulchre to butchery-cooking: Facies analysis, taphonomy and stratigraphy of the Upper Palaeolithic post burial layer from the San Teodoro Cave…
2020
Abstract The San Teodoro Cave is considered the most significant witness of the first, Epigravettian, human colonization of Sicily from the Italian continent. Furthermore the site is a paradigmatic horizon in the Pleistocene faunal record, demonstrating a progressive transition from mega faunas to smaller-sized, Boreal, faunas. The site has been repeatedly studied and excavated, with different aims and approaches, leading to an interpretation of Epigravettian burial site and daily attendance. Here we propose a reappraisal of the study of the stratigraphy of the site, and in particular of the bone-rich layer (PAL) accumulated over the red ochre layer that apparently sealed all the different …
L' Avventura dei Mille
2010
La situazione del 1860 era un intreccio che in tutto e per tutto assomigliava a un canestro di granchi. In questo clima Garibaldi, nato per l’azione, decise d’agire, stimolando le voglie di un’intera generazione che trovò nella spedizione il crogiolo della sua formazione e fu poi dimenticata. Giuseppe Nodari, soldato adolescente dell’ancien régime asburgico, che indossando la camicia rossa era diventato un borghese moderno italiano, ne è stato un esempio assai chiaro. I suoi disegni, ritrovati dopo anni di oblio e pubblicati integralmente per la prima volta in questo libro, sono d’un interesse clamoroso: raccontano in presa diretta, come in un film, la spedizione da Quarto a Palermo e costi…