Copper(II)–diaminosarcophagine‐functionalized SBA‐15: a heterogeneous nanocatalyst for the synthesis of benzimidazole,benzoxazole and benzothiazole derivatives under solvent‐free conditions

Solvent‐free organic reactions were studied over periodic mesoporous silica (SBA‐15) containing a Cu(II) organometallic complex. This heterogeneous catalyst was achieved by coordination of Cu(II) ions with the diaminosarcophagine ligand and then its grafting onto the surface of SBA‐15. This catalyst displayed ordered mesoporous channels, which implies an extremely high dispersion of the Cu(II) complex and the convenient diffusion of reactant molecules into the pore channels. Therefore, this catalyst can offer high activity and also facile separation or recycling when compared with its homogeneous counterparts. Copyright © 2015 John Wiley & Sons, Ltd.     

Remediation of copper ions from aqueous solution using hybrid magadiite: kinetics,isotherm and mechanism of removal

Research on Chemical Intermediates - This paper deals with the potential use of hybrid magadiite composite as an alternative adsorbent for the removal of copper ions. Na-magadiite was synthesized...     

Zinc electrodeposition on copper substrate using cyanide bath for the production of 66,67,68Ga

The electroplating of zinc is carried out in an alkaline cyanide bath. Operating parameters such as pH, temperature, and current density and amount of the electrolyte components are optimized. The optimum conditions of the electrodeposition of zinc were as follows: 2.7 g L⁻¹ ZnO, 7.1 g L⁻¹ KCN, 11.1 g L⁻¹ KOH, pH = 13–14, DC current density of ca 8.55 mA cm⁻² at 40–50 °C temperature with 89% current efficiency. SEM photomicrographs revealed fine-grained structure of the deposit from the bath.     

Dioxygenase-catalysed dihydroxylation of arene cis-dihydrodiols and acetonide derivatives: a new approach to the synthesis of enantiopure tetraoxygenated bioproducts from arenes

cis-Dihydrodiols of anthracene and benz[a]anthracene, and acetonide derivatives of the cis-dihydrodiols of benzene, fluorobenzene, biphenyl and phenanthrene have been identified as substrates for dioxygenase enzymes, yielding the corresponding enantiopure arene bioproducts, bis(cis-dihydrodiol)s and cis-diol acetonides respectively.     

Photonic crystal lens: from negative refraction and negative index to negative permittivity and permeability

We consider a dielectric photonic crystal made of cylindrical holes in a high index matrix. We show that a given finite size photonic crystal can mimic a homogeneous material whose permittivity and permeability are negative. We pay attention to the limitation of the homogeneous medium model and the vital role of the truncation of the crystal.     

A Dynamic Frictionless Elastic-Viscoplastic Problem with Normal Damped Response and Damage

We consider a mathematical model for the process of a frictionless contact between an elastic-viscoplastic body and a reactive foundation. The material is elastic-viscoplastic with internal state variable which may describe the damage of the system caused by plastic deformations. We establish a variational formulation for the model and prove the existence and uniqueness result of the weak solution. The proof is based on arguments of nonlinear equations with monotone operators, on parabolic type inequalities and fixed point.     

Electrodeposition iron target for the cyclotron production of 55Co in labeling proteins

Natural iron electrodeposition on copper substrate was studied with the aim of production of cobalt-55 radionuclide. ⁵⁵Co seems well suited for PET imaging due to its high abundance of positron decay (I _β+ = 76%), its relatively long half-life (T _1/2 = 17.5 h) and its mean positron energy (E _avg = 570 keV). The electrodeposition experiments were carried out by chloride bath. Operating parameters such as pH, temperature, current density and amount of the electrolyte components are also optimized. The optimum conditions of the iron electrodeposition were follows: 8 g/L FeCl₂, 2 g/L CaCl₂, pH = 1, DC current density of 21.3 A/dm² with a bath temperature of 75 °C temperature and 20% current efficiency. SEM photomicrographs demonstrated fine-grained structure of the deposit obtained from the optimum bath. The electroplated iron-target was irradiated with 29.5 MeV protons at current of 100 μA for 1 h and yields of about 31.25 MBq/μAh were experimentally obtained.