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- Author or Editor: S. Lukić x
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Abstract
The separation of tungstate and perrhenate anions on alumina from aqueous solutions of sodium chloride was investigated in dynamic conditions. The breakthrough curves for W and Re as the function of the ratio of their concentrations in the solution, were determined. The flow rate (3 ml/min), pH 2 and NaCl concentration (0.15 mol/l) were kept constant throughout the experiments. The breakthrough capacities Q 0.05, the capacities at C/C 0 = 0.5, the total column sorption capacities Q 0.9 and the utilization degrees or column efficiencies E, were determined. According to the obtained data the separation factors α W/Re = Q w/Q Re were calculated.
Abstract
Results of thermal investigations of the amorphous five-component chalcogenide system Ge20As14(SexS1−x)52I14 are presented. Differential thermal analysis (DTA), derivative differential thermal analysis (DDTA), and dilatometry were employed to determine the temperatures of softening and partial crystallization of the samples. Thermal treatment of the samples at 1000°C and recording of the corresponding thermogravimetric (TG) and derivative thermogravimetric (DTG) curves allowed an elucidation of the full mechanism of their decomposition, which proceeds via seven characteristic phase transitions.
Abstract
The object of the paper is an investigation of the glasses of the (As2S3)x(AsSe0.5Te0.5I)100-x. type for 65≤;x≤;95, using methods of thermomechanical analysis. Values of the thermal coefficients of linear expansion in solid and visco-plastic phase were determined. it was shown that introducing arsenic-sulfide in glass-matrix AsChI, i.e. (AsSe0.5Te0.5I), leads to an increasing stability of these glasses. The characteristic temperatures of softening Tg and the temperature of the beginning of deformation t w increase by increasing content of As2S3. The analytical forms of dependence of four significant physical values αg, αl, Tg, Tw, as a function of As2S3 content in the structure of glasses were fitted.
Abstract
The thermal decomposition of copper(II) complexes with salicylaldehyde S-methylthiosemicarbazone of general formula Cu(HL)X·nH2O (X=Py+NO3, NCS, 0.5SO4) and [Cu(L)NH3]·H2O was investigated in air atmosphere in the interval from room temperature to 1000°C. Decomposition of the complexes occurred in several successive endothermic and exothermic processes, and the residue was in all cases CuO.
Transition metal complexes with thiosemicarbazide-based ligands
XI. Dioxovanadium(V) complexes with aromatic aldehyde thio and S-methylisothiosemicarbazones
The unit cell parameters and the space group of the investigated compound were determined by means of X-ray diffraction.
Abstract
The paper describes results of a study of glasses of the type Cux (AsSe1.4 I0.2 )100–x for x =0, l, 5, 10, 15, 20 and 25 at% Cu, by the methods of thermomechanical analysis. Values of the thermal coefficients of linear expansion in solid and visco-plastic phase were determined and the dependence of this parameter on copper concentration was established. The experimental method used enabled the determination of characteristics glass transition temperature and the temperature of the beginning of deformation, and it was found that these parameters increase with increase in the copper content.
Abstract
Triammonium-N-dithiocarboxyiminodiacetate, (NH4)3L, a new dithiocarbamato derivative of iminodiacetate, has been synthesized. The coordination properties of the ligand were tested in reactions with copper(II), nickel(II) and palladium(II) salts in acidic solutions. Complexes with a general formula M(H2L)2 were obtained, with the coordination taking place through the sulfur atoms of the dithiocarbamate moiety. The new compounds were characterized by elemental analysis, UV/VIS and IR spectroscopy, thermal analysis and magnetic measurements. In addition, the ligand was characterized by 1H- and 13C-NMR spectroscopy and molar conductivity measurements. The copper(II) complex is paramagnetic, while the nickel(II) and palladium(II) compounds are diamagnetic. The thermal decomposition of all compounds is continuous and the thermal stability of the complexes is higher than that of the ligand, as expected.
