Search results for "COPP"
showing 10 items of 3147 documents
Synthesis of copper(II) complexes of new carbon-scorpionate ligands
2009
A set of new “carbon-based” scorpionate ligands based on S- and N-containing heterocyclic moieties have been synthesized. They offer the advantage of a higher stability with respect to the “classical” boron-based scorpionate ligands and also a certain degree of hydrophilicity. The synthesis of these ligands was accomplished by the coupling reaction of the N-methylimidazolyllithium with a suitable electrophilic partner. The reaction yield ranges from 40% to 65%. Preliminary results on the synthesis and characterization of the related copper(II) complex are also presented.
Syntheses, Structures, and Magnetic Properties of Copper( II ) Complexes with 1,3‐[Bis(2‐pyridylmethyl)amino]benzene (1,3‐tpbd) as Ligand
2004
The dinuclear copper(II) complexes {[Cu2(1,3-tpbd)(H2O)(OAc)2](ClO4)2}0.23{[Cu2(1,3-tpbd)(H2O)2(OAc)](ClO4)3}0.77·0.77H2O (1), [Cu2(1,3-tpbd)(H2O)2(OAc)2](ClO4)2·2H2O (2), and the tetranuclear copper(II) complex [Cu4(1,3-tpbd)2(H2O)2(SO4)4]·8H2O (3) {1,3-tpbd = 1,3-bis[bis(2-pyridylmethyl)amino]benzene} were synthesised and structurally characterised by X-ray diffraction. Variable-temperature (2.0−290 K) magnetic susceptibility measurements on these complexes as well as on the dinuclear copper(II) complex [Cu2(1,3-tpbd)(H2O)2(ClO4)3]ClO4 (4) (whose structure was published earlier) were performed. In contrast to 2 and 3, significant ferromagnetic coupling with J = +9.3 cm−1 was observed for …
Analisi della prassi costruttiva locale per la salvaguardia degli elementi tecnici della tradizione: i tetti nell’edilizia minore della sicilia occid…
2008
Da alcuni anni conduciamo ricerche finalizzate alla individuazione di tipologie costruttive di antichi edifici che, per le peculiarità da loro possedute, possano costituire esemplificazioni progettuali per il recupero . Si vuole ricostituire l’arcaico concetto di “regola d’arte” che, se rivisitato nei suoi valori costruttivi e codificato nei suoi aspetti pratici, può assumere una certa utilità nel recupero di antiche tecniche costruttive. Riteniamo che un tale obiettivo oggi possa essere raggiunto attraverso indagini storiche, da cui dedurre le modalità empiriche con cui venivano realizzati le parti componenti un edificio, e verifiche che, effettuate in termini scientifici grazie all’uso di…
Growth and photo-electrochemical behaviour of Cu2O nanowires
2008
Study of a Novel Electrochemical Method for Copper Recovery from Waste Printed Circuit Boards
2017
This study was carried out to recover copper from printed circuit boards of waste computers through an electrochemical process. To simplify the overall recovery process, large pieces of printed circuit boards were used instead of pulverized samples. In particular, these large pieces were directly used as an anode for copper electrorefining. For this purpose, electronic components and solder mask were initially removed from the boards. The electronic components can be treated separately to recover precious metals using various methods. The removal of solder mask was necessary to expose copper layers to the electrolytic solution and it was removed by a chemical treatment with sodium hydroxide…
Electrochemical deposition of different semiconductors for application in solar cells
2011
Experimental investigation and modelling for sulphuric acid recovery by diffusion dialysis
2018
Sulphuric acid is known to be one of the key inorganic acid and has been widely used in chemical reaction and metal industries for surface treatments as in the copper electroplating process. During these processes, large amounts of waste sulphuric acid solution are generally generated, containing high concentrations of metals and acid. The possibility of recover and reuse the sulphuric acid in the process could avoid environmental contamination and reduce costs of the disposal. Among several separation methods, diffusion dialysis (DD) is becoming more and more attractive thanks to the recent important advances in ion exchange membranes (IEMs) field and because of its clean nature and operat…
Diffusion dialysis for the treatment of H2SO4-CuSO4 solutions from electroplating plants: Ions membrane transport characterization and modelling
2021
Diffusion dialysis (DD) is proposed to separate and recover mineral acids and transition metals from electroplating industry process waters promoting a circular approach of resources recovery. In this work, a DD module with two anionic membranes (Fumasep FAD and Neosepta AFN) are used for the separation of H2SO4 from Cu2+ containing solutions. The membrane performances with sole H2SO4 solutions (0.2–2 M) and sole CuSO4 solutions (0.8–1.1 M Cu2+) and with mixtures of H2SO4 (0.6 M) and CuSO4 (0.2–1.1 M Cu2+) as feed are studied. H2SO4 recovery efficiency decreases as the concentration of acid increases. For H2SO4 solutions, the water drag flux from the retentate to the diffusate prevails agai…
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…
Eticità dell'adozione alla luce delle attuali trasformazioni familiari
2016
Inizio con una definizione che utilizzo spesso e che apparentemente non ha granché di eccezionale, ma che ha, invece, una sua particolarità: non esiste un modo di essere e vivere che sia il migliore per tutti; la famiglia di oggi non è né più né meno perfetta di quella di una volta, ma è diversa perché le circostanze sono diverse. Mi sembra una definizione che possa essere condivisibile da tutti. La particolarità è che non è per niente attuale, nel senso che è stata pronunciata qualche anno fa. E questo mi fa un po’ pensare che forse tra altri centocinquanta anni sarà ancora vera. Ma, allora, di quale famiglia parliamo? Del resto, se nel 1880 si rifletteva su quanto la nuova famiglia fosse …