Search results for " Metal"
showing 10 items of 2159 documents
Análisis de dos clavos y un rodamiento del pecio Bou Ferrer (La Vila-Joiosa, Alicante)
2020
El pecio Bou Ferrer contiene los restos sumergidos de una nave de comercio romana altoimperial que conserva una parte importante de su arquitectura naval. Analizamos tres objetos de metal procedentes del yacimiento, dos clavos y un hipotético rodamiento de la bomba de achique, para conocer la composición elemental. El resultado ha revelado que los clavos son de cobre y el cojinete de una aleación ternaria de bronce que contiene cobre, estaño y plomo. Este hallazgo abre la posibilidad de investigar el uso especializado del bronce plomado para mejorar el rendimiento mecánico de las bombas de achique en los barcos romanos. The Bou Ferrer wreck contains the underwater remains of a high-empire R…
Bio-char from dead Posidonia oceanica residues as adsorbent towards toxic metal ions
2018
Recently, the pyrolysis of biomass from different algal species and from the Mediterranean sea plant Posidonia oceanica have been proposed for renewable fuel production with a maximum oil yield of 54.97% at 500°C, and high heating values of 24-32 MJ kg-1[1,2]. The pyrolysis produces a large amount of bio-char and the accumulation of this byproduct may cause solid waste pollution problems. Although the composition and properties of bio-char depend on the raw material and on the carbonization process, it is on average composed of amorphous carbon with a highly functionalized surface, which makes it reactive towards inorganic and organic compounds [3]. Considering the reactivity of bio-char, t…
Prediction models based on soil properties for evaluating the uptake of eight heavy metals by tomato plant (Lycopersicon esculentum Mill.) grown in a…
2021
The aim of this study is to design de novo prediction models in order to gauge the likely uptake of eight heavy metals (Al, Cr, Cu, Fe, Mn, Ni, Pb and Zn) by Lycopersicon esculentum, the tomato plant. Uptake was assessed within the plant’s root, stem, leaf and fruit tissues, respectively. The plant was cultivated in soil amended by different application rates of sewage sludge, i.e. 0, 10, 20, 30 and 40 g/kg. The roots exhibited markedly elevated heavy metal concentrations compared to the above-ground plant components, with the exception of the quantity of Ni in the leaves. Apart from Al, Fe and Mn, a bioconcentration factor >1 was identified for all heavy metals. Excluding Ni in the leaves,…
Biotechnology of Rhodococcus for the production of valuable compounds
2020
Abstract Bacteria belonging to Rhodococcus genus represent ideal candidates for microbial biotechnology applications because of their metabolic versatility, ability to degrade a wide range of organic compounds, and resistance to various stress conditions, such as metal toxicity, desiccation, and high concentration of organic solvents. Rhodococcus spp. strains have also peculiar biosynthetic activities that contribute to their strong persistence in harsh and contaminated environments and provide them a competitive advantage over other microorganisms. This review is focused on the metabolic features of Rhodococcus genus and their potential use in biotechnology strategies for the production o…
BioMet14 XIV PharmacoBioMetallics Pisa, 24-25 ottobre 2014
2014
BIOMONITORIG ACTIVITIES OF “COMPRENSORIO DI PACE DEL MELA”.ANALYSES OF AIR QUALITY DATA
2007
The “Assessorato Territorio e Ambiente” of the Regional Sicilian Government and the “Ingegneria e Tecnologie Agro Forestali” (ITAF) Department, Palermo University, have been involved in a study (D.R.S. N° 473) concerning the occurrence of environmental pollution by heavy metals in the "Comprensorio territoriale di Pace del Mela". The involved local administrations (“comuni”) in the area of interest are: Condrò, Gualtieri Sicaminò, Milazzo, Pace del Mela, S.Filippo del Mela, Santa Lucia del Mela, San Pier Niceto. Naturalistic aspects and landscape relevance of the “Pace del Mela” area is supported by the existence of three Natural Reserves, twelve Sites of Community Interest (S.I.C.) and a Z…
Long-term impact of 19 years' farmyard manure or sewage sludge application on the structure, diversity and density of the protocatechuate-degrading b…
2012
International audience; Impact of long-term biosolids application on soil-living micro-organisms key players of ecosystemic services is scarcely reported. Here, the impact of the 19 year-long application of farmyard manure (FM) and sewage sludge (SS) organic fertilisation regimes on the protocatechuate-degrading bacterial (pca) community was estimated by comparison to a mineral fertilisation regime (U). The structure, diversity and density of the pca community were determined using pcaH, a gene encoding the protocatechuate 3,4-dioxygenase. Ten years after the last application, the structure of the pca community in soils amended with 55100 (100 t/ha/2 years) and to a lesser extent with FM (1…
4,4′-Substituted biphenyl coronands. Preparation of a new selective fluorescent sensor for mercury salts
2006
Six new 4,4′-substituted biphenyl coronands have been prepared. The ligands containing dimethylamino groups in the biphenyl moiety have been used in transition metal cations’ complexation and one of them (3) has demonstrated to be a selective fluorescent sensor for mercury. Stoichiometries of the formed complexes and complexation constants have been determined by titration experiments. In addition, the extractant ability of some ligands has also been studied. Finally, the electrochemical properties of some of these ligands are also described.
Redox-active crown ethers derived from biphenyl. Electrochemical and spectroscopic study of binding processes with alkali, alkali-earth and mercury s…
1998
Abstract Three new electroactive ligands, 3a, 3b and 3c, that contain the biphenyl frameworks in their structure were prepared. These new ligands presented three interesting characteristics: 1) they exhibited a reversible oxidation, 2) the oxidation induced a conformational change in the crown moiety and 3) they had two different coordination centers, the crown ether and the dimethylamino groups. Electrochemical and spectroscopic studies using alkali, alkali-earth and mercury salts were carried out.
Synthesis, solution and electrochemical behaviour of new aza-crown ethers derived from biphenyl
2000
Macrocyclic ligands L1–L4 containing biphenyl units have been synthesized. Potentiometric and voltametric studies in the presence and the absence of transition metal cations have been carried out. The relationship between the conformation of the ligand and oxidation states has been also considered. The crystal structure of [HgL2(CN)2]·2Hg(CN)2 has been elucidated by X-ray diffraction techniques.