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in the search for new potential catalysts of selective oxidation of organic compounds. It is known that in one of the cross sections of the CuO–V 2 O 5 –Fe 2 O 3 system, i.e. in the system FeVO 4 –Cu 3 V 2 O 8 , a double vanadate(V) of the
References 1. Yokoyama Y , Inoue H , Fukaura K , Inoue A : Relationship between the liquidus surface and structures of Zr–Cu
synthetic inhibitors, which are toxic and obtained from non-renewable sources. 2 Materials and method 2.1 Materials The materials used in this study include Al, Zn and Cu scraps, which are melted to produce Al–Zn–Cu alloys samples (7,093 series). Other
automotive market for light-metal shapes continues to grow at an increasing rate. In particular, the aluminum–silicon (Al–Si) and aluminum–silicon–copper (Al–Si–Cu) cast alloys are widely used in different application fields because of their good castability
Abstact
5-Chloro-2-nitrobenzoates of Co(II), Ni(II) and Cu(II) having formulae Co(C7H3O4NCl)2·3H2O, Ni(C7H3O4NCl)2·3H2O and Cu(C7H3O4NCl)2·2H2O, were obtained as polycrystalline compounds. From the IR spectra analysis of complexes, sodium salt and according to the spectroscopic criteria the carboxylate ions seem bidentate groups. The complexes of Co(II) and Cu(II) lose the water of crystallization in one step at 363–523 K. The Ni(II) complex loses it in two stages in the ranges of 323–378 and 378–523 K, respectively. The compounds follow the Curie–Weiss law. The magnetic moment values experimentally determined change from 4.53 to 4.55 μB for Co(II) complex, from 2.34 to 2.97 μB for Ni(II) 5-chloro-2-nitrobenzoate and from 1.80 to 1.90 μB for Cu(II) complex.
Various copper(II) complexes as guests were immobilised among the layers of montmorillonite or on silica gel as hosts. Anchoring took place through hydrogen bonds and ion exchange for montmorillonite, while the forces of interaction were either hydrogen bonding or covalent bonds for the copper complex-silica gel nanohybrids. The thermal stabilities of these substances were studied under oxidizing atmosphere and it was found that anchoring increased the durability of the host-guest complexes relative to the host-free ones.
Abstract
Sulfacetamide sodium is a widely prescribed sulfonamide drug due to its topical antibacterial action on eye and skin. Four impurities are stated in the British Pharmacopoeia among which are sulfanilamide and dapsone. This work presents two specific, accurate and precise chromatographic methods for the simultaneous determination of a mixture of sulfacetamide sodium, sulfanilamide and dapsone. The first method is an isocratic RP-HPLC where the separation of components was achieved on C18 column. A green mobile phase was used consisting of methanol:water (60:40, v/v). The flow rate was 1.0 mL/min and effluent was monitored at 273 nm. The second method is a TLC-spectrodensitometric one where good separation was achieved by using silica plates and a mobile phase consisting of chloroform:dichloromethane:acetic acid (6:2.5:1.5, by volume). Determination was done by densitometry in the absorbance mode at 273 nm. Both methods were validated in compliance with ICH guidelines. They were also successfully applied for the determination of sulfacetamide sodium and its impurities in Ocusol® ophthalmic solutions. The obtained results were statistically compared to the results obtained by applying the official methods of analysis of each component where no significant difference was found with respect to accuracy and precision.
developed. The lead-free solders have two, three, or more alloying elements. The most frequently used alloying elements are as follows: bismuth (Bi) [ 8 , 9 ], indium (In) [ 10 , 9 ], zinc (Zn) [ 8 ], silver (Ag) [ 11 ], antimony (Sb) [ 12 ], copper (Cu
, does not have polymorphous varieties. CuO crystallises in the monoclinic system [ 9 ], and above 1,100 °C it undergoes thermal decomposition to Cu 2 O and O 2 [ 10 , 11 ]. To the best of our knowledge, the phase equilibriums settling in solid
Introduction Cybersex use (CU) refers to the use of the Internet to engage in sexually gratifying activities, including pornographic material or exchanging sexual messages ( Carnes, Delmonico, & Griffin, 2007 ; Cooper
