Reconstruction and operation of feeders with the use of electric heating

Based on the data from a thermal engineering analysis of feeders working on liquid or gas fuel. their main disadvantages were determined, namely, the low temperature homogeneity of the liquid glass and insufficient stability of the temperature regime. Ways of eliminating the disadvantages consist in complete or selective heating. The results of the operation of such feeders in some glass plants are presented.Translated from Steklo i Keramika, No. 3, pp. 4–6, March, 1996.Research Institute of Glass of the Khrustal' Scientific and Production Center     

Moisture absorption effects on the thermal and mechanical properties of wood flour/linseed oil resin composites

The thermal and mechanical behavior of new natural polymeric composite materials after exposure to humid environments must be well known and understood in order to predict their performance in final applications. For this reason, composites made from unsaturated polyesters based on linseed oil and filled with wood flour were exposed to environments of different relative humidities and their final properties were measured. In general, the equilibrium moisture content increased as the wood flour percentage increased. Dynamic mechanical tests performed in temperature scan mode were carried out in order to monitor the changes resulting from moisture absorption on the main transition temperature of the matrix (T_α). The temperature of this transition decreased as the amount of absorbed water increased, but the effect was partially reversible by re‐drying the samples. The mechanical properties were also strongly affected by moisture. The flexural modulus and ultimate stress of the composites decreased after equilibration in humid environments. Copyright © 2006 Society of Chemical Industry     

Nanostructured Films of Vanadium Borides

The elemental and phase compositions of films produced by rf magnetron sputtering of a VB₂ target are determined by x-ray diffraction, electron microscopy, and secondary ion mass spectrometry. The composition-depth profiles of the films are analyzed.__________Translated from Neorganicheskie Materialy, Vol. 41, No. 7, 2005, pp. 799–802.Original Russian Text Copyright © 2005 by Goncharov, Petukhov, Terpii, Ignatenko, Stupak.     

Phase formation,structure, and state of stress of nanostructured tantalum boride films

Nanostructured tantalum boride films have been synthesized using the method of nonreactive radio-frequency sputtering of TaB₂ target. The effect of sputtering regimes on the phase formation, structure, and the state of stress of the samples produced has been studied. The thickness of films was determined by multibeam interferometry and X-ray diffraction methods; the structure and phase composition of films were studied by X-ray diffraction, transmission electron microscopy, and scanning electron microscopy; and the chemical composition was determined by the secondary ion mass spectrometry. The change in the sputtering regimes affected the phase formation and the structure of the synthesized films and led to changes in their substructural parameters, namely, subgrain sizes, microdeformations of the crystal lattice, and the degree of texture and the level of macrostresses. Both textured stressed and nontextured stressless nanostructured films of tantalum borides have been obtained.     

Effect of impregnation on the degree of polymerization of cellulose during bleaching of sodapulped sugar cane bagasse

Samples of sugar cane bagasse pulps, digested at different times without and with previous impregnation, have been bleached and the bleached materials submitted to a detailed study of their degree of polymerization (DP) and the corresponding distributions. The respective results turn out that like in the case of the effect of impregnation on the digestion process, impregnation affects also the bleaching reaction of the digested samples, causing a further remarkable decrease of the degree of polymerization of the cellulose molecules and a deviation of its distribution from the character of a most probable one. The impregnated bleached materials show in addition to the decrease of their DP a certain, albeit slight, diminution in their tensile strength.     

Desaturation of fatty acids inTrypanosoma cruzi

Uptake and metabolism of saturated (16∶0, 18∶0) and unsaturated [18∶1(n−9), 18∶2(n−6), 18∶3(n−3)] fatty acids by cultured epimastigotes ofTrypanosoma cruzi were studied. Between 17.5 and 33.5% of the total radioactivity of [1-¹⁴C]labeled fatty acids initially added to the culture medium was incorporated into the lipids ofT. cruzi and mostly choline and ethanolamine phospholipids. As demonstrated by argentation thin layer chromatography, gas liquid chromatography and ozonolysis of the fatty acids synthesized, exogenous palmitic acid was elongated to stearic acid, and the latter was desaturated to oleic acid and 18∶2 fatty acid. The 18∶2 fatty acid was tentatively identified as linoleic acid with the first bond in the Δ9 position and the second bond toward the terminal methyl end. Exogenous stearic acid was also desaturated to oleic and 18∶2 fatty acid, while oleic acid was only converted into 18∶2. All of the saturated and unsaturated fatty acids investigated were also converted to a small extent (2–4%) into polyunsaturated fatty acids. No radioactive aldehyde methyl ester fragments of less than nine carbon atoms were detected after ozonolysis of any of the fatty acids studied. These results demonstrate the existence of Δ9 and either Δ12 or Δ15 desaturases, or both, inT. cruzi and suggest that Δ6 desaturase or other desaturases of the animal type are likely absent in cultured forms of this organism.