Transfer processes in heterogeneous reduction reactors

The results of experimental study are presented and mathematical models are proposed for heat and mass-transfer coefficients in a packed bed layer of reacting particles immersed in a liquid through which the reaction products are bubbled. It is shown that turbulence models based on taking into account the motion of bubbles, which rise under the action of buoyancy forces and set the liquid in swirling motion, quite adequately describe the transfer processes in gas—liquid systems, including the layer of dispersed particles.Translated from Teoreticheskie Osnovy Khimicheskoi Tekhnologii, Vol. 38, No. 6, 2004, pp. 611–615.Original Russian Text Copyright © 2004 by S. Panchenko, D. Panchenko, Glebova.     

Features of the mechanoluminescence of thin metal films excited by long and short laser pulses

We have studied the strain-induced luminescence from thin fine-grained films of various metals under the action of short (subnanosecond) and long (millisecond) laser pulses. The possible mechanism of luminescence excitation is considered, according to which the emission is due to the interaction between grain boundary dislocations and impurities occurring in the intergranular region.     

Effect of Shock-Wave Deformation on Acoustic and Elastic Properties of Titanium Nickelide in Phase Transformations

Metal Science and Heat Treatment -     

Expression of lysyl oxidase from cDNA constructs in mammalian cells: the propeptide region is not essential to the folding and secretion of the functional enzyme

Rat aortic lysyl oxidase cDNA was expressed under a metallothionein promoter in Chinese hamster ovary cells using a dihydrofolate reductase selection marker. One methotrexate-resistant cell line, LOD-06, generated by transfecting with full-length cDNA, yielded lysyl oxidase proteins consistent with the 50 kDa proenzyme and a 29 kDa mature catalyst. A second cell line, LOD32-2, was generated by transfection with a truncated cDNA lacking sequences which code for the bulk of the propeptide region. Both cell lines secreted apparently identical, 29 kDa forms of mature lysyl oxidase each of which catalyzed the deamination of human recombinant tropoelastin and alkylamines, consistent with the known specificity of lysyl oxidase. The secreted enzyme forms were inhibited by chemical inhibitors of lysyl oxidase activity, including beta-aminopropionitrile, phenylhydrazine, ethylenediamine, alpha, alpha'-dipyridyl, and diethyldithiocarbamate. Sensitivity to these agents is consistent with the presence of copper and carbonyl cofactors in the expressed enzymes, characteristic of lysyl oxidase from connective tissues. These results indicate the lack of essentiality of the deleted proprotein sequence for the proper folding, generation of catalytic function, and secretion of lysyl oxidase.     

Efficient electric-discharge CO2 laser with a prepulse formed by a generator with an inductive energy storage device

Results are presented of experimental investigations of a CO₂ laser pumped by a self-sustained discharge from a generator with an inductive energy storage device and a semiconductor current chopper. It is shown that the energy stored in the inductance of the discharge circuit can form a prepulse capable of depositing most of the energy in the active mixture for nearoptimum values of the parameter E/p. A radiation energy of 3 J was achieved in an electricdischarge laser with a 0.181 liter active volume with a 17% efficiency relative to the energy stored in the capacitive storage device. Pis’ma Zh. Tekh. Fiz. 24, 57–61 (February 26, 1998)     

Formation, retention, and waste of products of the atmospheric corrosion of metals. 3. Corrosion losses and the weight of retained products

The dependence m/K = f(K) (m is the weight of retained products per the unit weight of corrosion losses) on the integral weight of corrosion losses K, which is observed for zinc, carbon steel, copper, brass, aluminum, as well as Д16 and AM_д alloys, in cold, temperate, and tropical cimates, is analyzed. Two groups of empirical equations are proposed to express the functional dependence m/K = f(K). The weight of retained products of outdoor corrosion on zinc, steel, aluminum, and copper, which was calculated from these equations, adequately agree with the experimental weights of products after 1-year outdoor tests of these metals carried out since the late 50s of the past century in Russia and China. Original Russian Text ? Yu.M. Panchenko, P.V. Strekalov, 2006, published in Zashchita Metallov, 2006, Vol. 42, No. 1, pp. 90–102.