Search results for "pintura."

¿Qué habría pintado monet si hubiera sido chino? análisis de recursos pictóricos y gramaticales

2022

El acto de hablar es tan antiguo como el de dibujar, ambos forman parte de las expresiones humanas más instintivas. Para la adquisición del chino como L2 por parte de los hablantes nativos de castellano es conveniente elaborar una estrategia que no radique solo en la explicación gramatical y en ejercicios orales o escritos, es decir, que no debe limitarse a actividades basadas exclusivamente en las lenguas implicadas, la materna y la lengua meta. Como señaló Ciesielkiewitz (2009) 'la lengua nativa parece orientar, e incluso controlar el desarrollo de un nuevo proceso de aprendizaje lingüístico, puesto que el nuevo conocimiento parece someterse a un estricto control o revisión bajo los pará…

Miscelánea de pintura valenciana del siglo XVII

2010

Composition and Color of Maya Blue: Reexamination of Literature Data Based On the Dehydroindigo Model

2019

[EN] An analysis of literature data studying the composition and color of Maya blue (MB) type materials prepared from indigo, dehydroindigo, and different aluminosilicates, accompanied by new spectral data, is presented. After thermal treatment at above 100 degrees C, indigo-based specimens displayed Raman and UV-vis spectroscopic features common to those of equivalent dehydroindigo-based replicants, thus supporting the socalled dehydroindigo model (J. Phys. Chem. B 2006, 110, 6027-6039) in which the dehydroindigo/indigo ratio, increasing with temperature, is crucial to determine the color of MB and its variability. The current analysis supports the view of MB as a polyfunctional hybrid mat…

Characterizing archaeological bronze corrosion products intersecting electrochemical impedance measurements with voltammetry of immobilized particles

2017

Application of electrochemical impedance measurements to microparticulate deposits of copper corrosion products attached to graphite electrodes in contact with 0.10 M aqueous HClO4 electrolyte is described. The impedance measurements were sensitive to the applied potential and the amount of solid sample and were modeled taking into account the contribution of the uncovered base electrode. Several pairs of circuit elements provide monotonic variations which are able to characterize different corrosion compounds regardless the amount of microparticulate solid on the electrode. Application to a set of archaeological samples from the archaeological Roman site of Gadara (Jordan, 4th century AD) …

Hematite as an Electrocatalytic Marker for the Study of Archaeological Ceramic Clay bodies: A VIMP and SECM Study**

2022

[EN] The electrocatalytic effect exerted by hematite, a ubiquitous component of clay bodies, on the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) can be used to acquire information on archaeological ceramics. The solid-state voltammetric response of different hematite and ochre specimens, accompanied by SECM analysis in contact with 0.10 M HCl aqueous solution, is described. In air-saturated solutions, catalytic effects on the ORR and OER are accompanied by Fe(III)/Fe(II) and Fe(IV)/Fe(III) redox reactions. Such processes are conditioned by a variety of factors, the hydroxylation degree of the mineral surfaces being particularly influential, and exhibit significant var…

Thermosetting composites based on bronze particles for archaeological and artistic metal heritage cloning

2018

peer-reviewed Artificial Metals are polymeric semi-metallic composites obtained by combining thermosetting resins with atomized metal powders in order to achieve composite materials capable of reproducing metals, even in a rusty or corroded condition. These composites provide a solution for the reproduction of archaeological artefacts, sculptures, and ornaments for the purpose of conservation. This work explores mechanical properties of three different resins bronze composites loaded with two different proportions of metal filler. The degree of conversion of the samples was measured by differential scanning calorimetry (DSC) and flexural tests were carried out to determine their mechanical …

Solid-state electrochemical characterization of emissions and authorities producing Roman brass coins

2020

[EN] The voltammetry of immobilized particles (VIMP) is applied to describe the solid state electrochemistry of brass. This methodology, which involves sampling at the nanogram level, is applied to discriminate mints/authorities producing different Roman monetary emissions covering since the Republic (88 BCE) to Domitianus (55-96 CE) Upon attachment to graphite electrodes in contact with aqueous acetate buffer at pH 4.75, well defined voltarnmetric responses were obtained centered on Cu- and Zn-localized signals whose intensity can be correlated to EMP data, being sensitive to the contents of Zn (15-30 wt.%) and Sn (0.01-1.1 wt.%). Voltammetric data, combined with ATR-FTIR and FIB-PESEM/EDS…

"One-touch" voltammetry of microparticles for the identification of corrosion products in archaeological lead

2011

Voltammetry of microparticles is applied to the identification of lead corrosion products by means of an essentially non-invasive 'one-touch' technique based on the use of graphite pencil. This methodology permits the mechanical attachment of few nanograms of sample from the surface of lead archaeological artefacts to a paraffin-impregnated graphite electrode, which, upon immersion in aqueous electrolytes, provides distinctive voltammetric responses for litharge and cotunnite- anglesite-, cerusite-based corrosion products. The reported method is applied to the identification of corrosion products in archaeological lead pieces from different Iberian sites in Valencia (Spain). © 2011 WILEY-VC…

Characterization of Maya Blue Pigment in Pre-Classic and Classic Monumental Architecture of the Ancient Pre-Culombian City of Calakmul (Campeche, Mex…

2011

This paper presents the first evidence of the use of Maya Blue pigment in late pre-classic (c.300BC-300AD) architecture in the Maya Lowlands. This was detected combining an innovative technique, the voltammetry of microparticles (VMP), with atomic force microscopy (AFM), transmission electron microscopy (TEM), scanning electron microscopy/energy dispersive X-ray microanalysis (SEM/EDX), visible spectrophotometry and Fourier transform infrared spectroscopy (FTIR). The pigment was found on the polychrome facade of substructure IIC of pre-Columbian city of Calakmul (Campeche, Mexico). The identification of Maya Blue in this building may prove to be the earliest known use of this colour on the …

‘Maya chemistry’ of organic–inorganic hybrid materials: isomerization, cyclicization and redox tuning of organic dyes attached to porous silicates

2013

[EN] Association of indigo and lapachol dyes to aluminosilicate clays yields polyfunctional organic – inorganic hybrid materials forming Maya Blue-like systems. Upon partial removing of clay's zeolitic water by moderate thermal treatment, abundant isomerization, cyclicization and oxidation reactions occur defining a‘ Maya chemistry whose complexity could explain the versatile use of such materials in the pre-Columbian cultures and permits the preparation of polyfunctional materials potentially usable for therapeutic and catalytic purposes.