Search results for "Lead"
showing 10 items of 1360 documents
Alla ricerca dei fattori rilevanti nell’adozione dei sistemi di gestione della performance nelle amministrazioni pubbliche territoriali. L’analisi di…
2013
La ricerca scientifica ha dimostrato che la gestione della performance nelle amministrazioni pubbliche sta oggi spostando il proprio focus dalla mera attività di raccolta e rendicontazione di dati alla generazione di informazioni atte a supportare la formulazione di decisioni. L’analisi comparativa dei casi di studio analizzati in questo articolo mira ad identificare i fattori critici sottostanti alla progettazione e all’utilizzo dei sistemi di gestione della performance nelle amministrazioni regionali. Da questa analisi emerge che alcune variabili risultano essenziali ai fini di un’efficace adozione dei sistemi di performance management. Tra queste variabili sono annoverabili: il ruolo del…
Effects of environmental and occupational lead toxicity and its association with iron metabolism
2021
Abstract Background Discrepancies are present in the findings from clinical trials evaluating a physiological role of iron status in the lead-exposed population. Objective The purpose of this article was to summarize the current understanding of cellular mechanisms of lead toxicity and present a comprehensive review of existing clinical trials related to associations of lead poisoning and iron status. Although an association of iron metabolism pathways that are affected by lead intoxication has been studied, there are still aspects that remain to be elucidated. The existence of additional Pb uptake pathways besides DMT1 transporter-mediated is postulated to non-specifically regulate lead ab…
La medición de la felicidad en el trabajo y sus antecedentes : un estudio empírico en el area de alergología de los hospitales públicos españoles
2014
La búsqueda de la felicidad en el trabajo es un objetivo de enorme importancia para muchas personas y organizaciones. Sin embargo, existe una carencia importante la investigación acerca de cómo aumentarla (Chivato Pérez et al., 2011), así como una amplia dispersión de medidas relacionadas (Hackman, 2009). No se conoce ninguna medida que recoja con la suficiente amplitud la medición de la felicidad en el trabajo (Fisher, 2010), por lo que en este estudio proponemos un modelo integrativo que nos aporte la medida de este nuevo constructo. Proponemos que la felicidad en el trabajo se compone de tres constructos ya consolidados en la literatura. La primera hipótesis de esta investigación es que …
Effect of temperature on the growth of alfa-PbO2 nanostructures
2010
Abstract Ordered arrays of α-PbO 2 nanostructures were grown by galvanostatic anodic deposition into the channels of alumina templates. Electrodepositions were performed in an aqueous solution containing lead acetate and sodium acetate at pH 5.4. Bath temperature and electrodeposition time were varied to check their effect on the growth of nanostructures. It has been found that filling of alumina pores is independent of the time and electrodeposition temperature, whilst height and growth kinetics of nanostructures vary with both parameters. Temperature greatly influences morphology: wires grown at room temperature consisted of clusters of particles, leading to poorly compact structures, whi…
Application of Modified Tafel Analysis to the Identification of Corrosion Products on Archaeological Metals Using Voltammetry of Microparticles
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…
Comercio protohistórico: el registro del Nordeste peninsular y la circulación de mineral de plomo en Ibiza y el Bajo Priorato (Tarragona)
2012
[ES] Los estudios que hemos venido realizando indican que el plomo de la cuenca minera del Bajo Priorato (Tarragona) circula en el ámbito fenicio-tartesio. Sin embargo, los análisis realizados sobre un conjunto de muestras minerales y metálicas de la isla de Ibiza ponen de manifiesto la explotación de la galena argentífera local, cuyo uso coexiste en el yacimiento de sa Caleta con el mineral de Cartagena; no se documenta, en cambio, plomo de procedencia prioratina. Si sumamos a ello los datos relativos a las evidencias que aportan los registros cerámicos ibicencos y catalanes de los ss. VII a VI a.n.e., se va trazando un panorama que pone en evidencia la existencia de una pluralidad de rede…
Electrochemical Fingerprint of Archeological Lead Silicate Glasses Using the Voltammetry of Microparticles Approach
2016
9 págs.; 14 figs.; 1 tab.
Newly discovered orichalcum ingots from Mediterranean sea: Further investigation
2021
Abstract In February 2016, 47 ingots were found in the seabed of Contrada Bulala (Gela, CL, Italy) near the site where 40 ingots had previously been recovered. The ingots composition was determined to be a Cu - Zn alloy, dated by the archaeologist to the VI century B.C. This specific alloy was then known as Orichalcum. From an archaeological point of view, the first question raised about the new discovery was whether the ingots of the first and the second excavations belonged to the same shipwreck. Following the previous study, an elemental analysis was performed on the ingots from the second finding by using ICP-OS and ICP-MS techniques. The chemometric treatment of the analytical results …
Lead provenance for medieval decorated tile glazes from Brittany and Anjou (13th-14th c.)
2021
International audience; Medieval pavements composed of lead-glazed tiles decorated with a variety of techniques continue to inspire questions about the organisation of glaze manufacture, and the supply and origin of lead materials. The tiles analysed in this study are from Suscinio I (a 13th-century pavement) and Suscinio II (a 14th-century pavement), at the Château of Suscinio in Brittany, and also from the 14th-century pavement at the fortified manor house in Brain-sur-Allonnes, Anjou. Lead isotope analysis (LIA) was used to examine samples from 44 lead-glazed tiles, 29 of which are transparent, while 15 are tin-opacified (an exogenous technique in these regions during this period). Five …
Inadvertent climate modification due to anthropogenic lead
2009
Atmospheric particles are thought to initiate the majority of terrestrial precipitation. Field-based measurements of ice-crystal residues, together with controlled environment experiments on artificial clouds, suggest that anthropogenic lead-containing particles are among the most efficient ice-forming substances in the atmosphere.