reduction

Research of processes of chemical preposition of nickel as a filler of polymer hydrogels

The kinetic characteristics of the reaction of nickel precipitation by hypophosphites in the volume of the solution were studied, depending on the pH of the medium, temperature, oxidant content, nature and concentration of the activator, and the presence of a water-soluble polymer –polyvinylpyrrolidone (PVP). It was found that the presence of PVP in the solution affects the duration of the induction period and the rate of the reduction reaction, and the nature of the effect of PVP significantly depends on the pH of the medium.

Synthesis of Some Azo Dyes Based on 2,3,3-Trimethyl-3H-indolenine

New azo compounds on the base of 2,3,3-trimethyl-3H-indolenine were synthesized and characterized by FT-IR, NMR, and Mas-spectral analysis. The synthesis was conducted in three different pathways: 1) by reducing the nitro compound with Zn/NaOH in alcohol; 2) by heating of 2,3,3-trimethyl-3H-indolenine-5-amine in the presence of MnO2 in toluene, and 3) by diazotization of 2,3,3-trimethyl-3H-indolenine-5-amine and treating the resulting diazonium salt with the appropriate coupler.

Low-Pressure Discharge Plasma Treatment of Aqueous Solutions with Mn, Cr and Fe

The effect of low-pressure glow discharge on the formation of peroxide and the degree of oxidation of Mn, Cr and Fe was studied in the aqueous solutions of different compounds. The plasma treatment causes the reduction of Mn(VII) through Mn(IV) to Mn(II), Cr(VI) to Cr(III) and oxidation of Fe(II) to Fe(III). Among other reactive species, peroxide formed under the action of plasma treatment takes an active part in redox reactions. The concentration of peroxide usually increases with treatment time, but its presence is detected only after completion of active redox processes.

Reduction of the gravity vertical gradients to a spherical surface

The GOCE mission has produced gravity gradient data during 2009–2013 years. Various data sets were obtained, such as: tensor of second derivatives in different systems, satellite orbit parameters, the models of the gravitational field of the Earth. In contrast to the direct approach, space-wise-approach, and time-wise approach the construction of the spherical grid of gradients were orthogonality relationships are carry out, was developed via upward/downward continuation to sphere. This paper considers the vertical gravity gradients zz V (EGG TRF2 [Gruber Th., 2010]) in particular.