Specific Features of Ion-Exchange Zinc(II) Extraction from Washing Water of Zinc Plating

Specific features of ion-exchange purification of washing water formed in zinc plating in an alkaline medium are considered. The parameters of extraction of zinc ions and regeneration of ion-exchange resins are optimized.     

Ion-exchange recovery of nickel(II) from wash water formed in electroless plating in acid hypophosphite solutions

Kinetic aspects of extraction of Ni(II) ions with KU-2–8 cation-exchange resin in the Na⁺ form from wash water produced in electroless nickel-plating were studied. The optimal conditions and parameters of ion-exchange purification and regeneration of the cation-exchanger were determined.     

Nonlinear dynamics of semiclassical spin in a time-dependent magnetic field

The dynamics of magnetic nanoclusters (or molecules) with a large spin in a magnetic field whose strength varies in proportion to time is analyzed. Such a field breaks the symmetry relative to rotations through 2π, as well as clockwise and counterclockwise rotations, and induces a number of new coherent quantum effects in the spin dynamics, such as the formation of a band energy spectrum with continuous spin states or the emergence of “Bloch” oscillations in spin precession and interband Zener tunneling. Bloch oscillations are manifested in experiment as equidistant identical jumps on the magnetization curve. The interband Zener tunneling gives rise to additional jumps and peaks on the susceptibility of the system.     

Features of Cr(III) Cation-Exchange Recovery from Wash Water of Standard Chrome Plating

Features of treatment of the standard chrome plating wash water to remove Cr(III) with KU-1 cation exchanger in the H form were considered. The optimal conditions of Cr(III) recovery and ion exchanger regeneration were determined.     

Structure and properties of aluminum coatings obtained by the cold gas-dynamic spraying method

Structure and properties of aluminum coatings deposited onto steel substrates by the cold gas-dynamic spraying (CGS) method were examined. Aluminum CGS coatings fundamentally differ from their thermal counterparts as they enable the formation of heavy-duty layers of metal particles on substrates at temperatures below 500 K. A dense, low-porosity coating is found to form, tightly bound to the base metal. The adhesion strength is shown to weakly depend on the thickness of the sprayed coating due to the compressive stress present in the surface layer. A qualitative model for the coating formation process is proposed. This work was supported by the Russian Foundation for Basic Research (Grants Nos. 03-02-16329 and 05-07-90172).     

Preparation of γ-aminobutyric acid using E. coli cells with high activity of glutamate decarboxylase

γ-Aminobutyric acid (GABA) is a major inhibitory neurotransmitter synthesized in the central nervous system from glutamate by glutamate decarboxylase (GAD). It has applications in the production of many drugs. The technology of GABA synthesis by treating L-glutamic acid with the cells of the gene-engineered GAD superproducer strain of Escherichia coli GAD K10 was developed. Cell growing in the presence of 0.02 mM pyridoxal phosphate (PLP) causes the 2- to 2.5-fold increase of total productivity of the cells. The best way to prepare the cells for the reaction was their thermal activation by pretreatment for 1 h at 53°C. The optimal conditions for this reaction were 37°C and pH 4.6. The rate of the enzymatic reaction is the function of acetate concentration with the maximum at 0.5 M acetate. The total amount of GABA synthesized using 1 g of wet cells reached 23–25 g. The final concentration of GABA in the reaction medium was 280–300 g/L. The yield of the product was about 99%.     

Ultrafast Spin Dynamics in the Iron Borate Easy-Plane Weak Ferromagnet

Journal of Experimental and Theoretical Physics - Ultrafast processes of the spin dynamics in iron borate FeBO3 are considered theoretically; the mechanisms responsible for excitation of...     

Designing a relativistic-electron-beam injector with a macrostructural grid

V. I. Lenin All-Union Electrical Engineering Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 34, No. 3, pp. 309–318, March, 1991.