Search results for " Copper"
showing 10 items of 102 documents
Growth and photo-electrochemical behaviour of Cu2O nanowires
2008
Electrochemical deposition of different semiconductors for application in solar cells
2011
Early pastoral communities in the mountains of Sicily. Prehistoric evidence from Vallone Inferno (Scillato) in the palaeoenvironmental framework of t…
2021
Abstract This paper discusses the Middle Neolithic and the Early Bronze Age phases of the occupation of a rock shelter at Vallone Inferno (Scillato, Palermo) in Sicily. Vallone Inferno is a key site for studying the early establishment and development of pastoralism in the prehistoric mountainous environments of Sicily. Seasonal use of the site as a shelter is documented for the earliest pastoral communities that exploited the Madonie mountain range. The results of the analysis of pottery and lithic assemblages contribute to the definition of two chronocultural frameworks that were linked by the same economic subsistence base. The special role of obsidian emerges, while the mobility pattern…
Reactivity of antitumor coinage metal-based N-heterocyclic carbene complexes with cysteine and selenocysteine protein sites
2021
Abstract The reaction of the antitumor M(I)-bis-N-heterocyclic carbene (M(I)-NHC) complexes, M = Cu, Ag, and Au, with their potential protein binding sites, i.e. cysteine and selenocysteine, was investigated by means of density functional theory approaches. Capped cysteine and selenocysteine were employed to better model the corresponding residues environment within peptide structures. By assuming the neutral or deprotonated form of the side chains of these amino acids and by considering the possible assistance of an external proton donor such as an adjacent acidic residue or the acidic component of the surrounding buffer environment, we devised five possible routes leading to the binding o…
NaI/CuI–II heterometallic cages interconnected by unusual linear 2-coordinate OCN-Cu(I)-NCO links: synthesis, structural, magnetostructural correlati…
2009
A new Na(I)/Cu(I-II) heterometallic coordination complex [Cu(2)L(2)Na(NCO)(2)Cu](n) (1) with an unusual architecture has been synthesised. In 1 cyclic Na-O-Cu-O-Cu cages constructed by the tetradentate N(2)O(2) donor Schiff base ligand (H(2)L = N, N'-bis(2-hydroxyacetophenone) propylenediimine) are interconnected to each other by a rare singly end-to-end bridged OCN-Cu(I)-NCO link generating 1D chain. The complex has been characterised by elemental, spectral and structural analysis. The cyclic voltammogram of 1 has been compared with the analogous complexes. Cryomagnetic susceptibility studies indicate the copper(II) centers in the cyclic Na-O-Cu-O-Cu cages are antiferromagnetically coupled…
Isomerization and rearrangement of (E)- and (Z)-phenylhydrazones of 3-benzoyl-5-phenyl-1,2,4-oxadiazole: evidence for a “new” type of acid-catalysis …
2008
A kinetic investigation in methanol of the title reaction has evidenced the occurrence of two processes: the 1-E1-Z isomerization and the rearrangement of the (Z)-isomer into the relevant 4-benzoylamino-2,5-diphenyl-1,2,3-triazole (1-Z T). The latter reaction is in line with the ability of the (Z)-phenylhydrazones of 3-benzoyl-1,2,4-oxadiazoles to undergo the so called mononuclear rearrangement of heterocycles (MRH). The occurrence of both the examined reactions is dependent on a Lewis-acid-catalysis. The obtained results have shown the possibility of a ‘new’ type of acid-catalysis (bifunctional catalysis by Lewis salts) in the MRH. This catalysis operates through a completely different me…
Thermally Regenerative Ammonia Batteries for Waste-Heat Exploitation
2018
It is widely accepted that one of the most important issue to be faced by the scientific community is how to sustain the modern way of living and the related energy demand. While a long term target is the transition to a full-renewable energy system, a closer exigency is the optimization of the processes already existing. It has been calculated that about 370.41 TWh of potential energy is annually lost in Europe in the form of waste-heat from the industrial sector [1]. Waste heat comprises all the thermal energy with a temperature below 130 °C [2] (or 300 °C [1]), that hardly can find a useful application with the state of the art industrial technologies. Indeed, electrochemical technologie…
Anaerobic Degradation of Environmentally Hazardous Aquatic Plant Pistia stratiotes and Soluble Cu(II) Detoxification by Methanogenic Granular Microbi…
2021
The aquatic plant Pistia stratiotes L. is environmentally hazardous and requires effective methods for its utilization. The harmfulness of these plants is determined by their excessive growth in water bodies and degradation of local aquatic ecosystems. Mechanical removal of these plants is widespread but requires fairly resource-intensive technology. However, these aquatic plants are polymer-containing substrates and have a great potential for conversion into bioenergy. The aim of the work was to determine the main patterns of Pistia stratiotes L. degradation via granular microbial preparation (GMP) to obtain biomethane gas while simultaneously detoxifying toxic copper compounds. The compos…
ChemInform Abstract: Thermoelectric Transport in Cu7PSe6with High Copper Ionic Mobility.
2014
The copper ion conducting argyorite-type title compound is synthesized from the elements (evacuated quartz ampule, 1323 K, 3 h, and 773 K, 72 h) and its thermoelectric transport properties are studied.
Switch between tyrosinase and catecholoxidase activity of scorpion hemocyanin by allosteric effectors
2008
AbstractPhenoloxidases and hemocyanins have similar type 3 copper centers although they perform different functions. Hemocyanins are oxygen carriers, while phenoloxidases (tyrosinase/catecholoxidase) catalyze the initial step in melanin synthesis. Tyrosinases catalyze two subsequent reactions, whereas catecholoxidases catalyze only the second one. Recent results indicate that hemocyanins can also function as phenoloxidases and here we show for the first time that hemocyanin can be converted to phenoloxidase. Furthermore, its substrate specificity can be switched between catecholoxidase and tyrosinase activity depending on effectors such as hydroxymethyl-aminomethan (Tris) and Mg2+-ions. Thi…