Narrowband surface-acoustic-wave filters in RF identification systems

Low-loss narrowband surface-acoustic-wave filters designed for operation in RF identification devices in the frequency range 860–890 MHz are developed and investigated. Software is developed on the basis of the theory of coupled modes. A procedure for calculating a resonator transversely coupled structure is presented. This procedure provides good agreement between experimental and theoretical results. The manufactured filters are based on the resonance structures made on single-crystal quartz substrates by means of liftoff (explosive) photolithography and a batch-fabrication technique.     

Stress-strain state of tight joints under a bending moment

The stress strain state of tight joints under the action of a flexural torque is simulated by the finite-element method. The stress intensity at the contact zone in determined in characteristic cross sections of the shaft and the joint. The conditions of possible joint opening are established.     

The formation of smooth spalls in steel during the interaction of glancing detonation waves

A study is made of the formation of smooth spalls in steel specimens when their surfaces are blasted by explosive charges via a glancing detonation wave. When a steel specimen is blasted with an explosive, behind the front of glancing shock waves of compression two glancing shock waves of rarefaction, propagating toward each other, form, the interaction of which produces in the steel a smooth spall in the form of a dihedral angle. It is shown that a variation of the composition of the explosive (TNT, plastic explosive, TG 50/50 alloy) of a given thickness changes the distance from the vertex of the dihedral angle to the surface at which the charge was placed.VNIIÉF, Arzamas-16 607200. Translated from Fizika Goreniya i Vzryva, Vol. 30, No. 4, pp. 138–140, July–August, 1994.     

Surface-acoustic-wave filters with a high input power for a nominal frequency of 2170 MHz for communication systems and radar and telecommunications equipment

The basic design of microwave filters based on surface acoustic waves with a high input power for specialized communication systems and radar and telecommunications equipment is developed.     

Hygienic evaluation of acetone cyanohydrin transformation in water

The study of acetone cyanohydrin (ACH) showed that it is an unstable substance. Its stability in water depends on pH of water and less so on its initial concentration; water temperature and biota are insignificant. Acetone and cyanid-ion, forming from ACH, after 20 days are transformed into a complex of cyan compounds.     

Optimizing the composition of cellulase enzyme complex from <Emphasis Type="Italic">Penicillium verruculosum</Emphasis>: Enhancing hydrolytic capabilities via genetic engineering

Modern technologies for the enzyme hydrolysis of cellulose-containing raw materials allow the production of sugars from which alcohols (biofuel), organic and amino acids, biopolymers, feed additives, and other value-added products can be obtained via microbiological conversion. Three types of cellulolytic enzymes are required for the bioconversion of cellulose containing materials: endoglucanase, cellobiohydrolase, and ß-glucosidase. The prospects for improving the hydrolytic capabilities of the enzyme complex secreted from Penicillium verruculosum are investigated in this work by means of genetic engineering to add different combinations and ratios of homologous and heterologous cellulases: endoglucanase IV (EGIV) of Trichoderma reesei, endoglucanase II (EGII), and cellobiohydrolase I (CBHI) of P. verruculosum, along with ß-glucosidase (ß-GLU) of Aspergillus niger. The optimum ratio of components is determined and the catalytic activity of enzymatic complexes is increased by as much as 100%.     

New platforms for 3-D microarrays: Synthesis of hydrophilic polymethacrylate monoliths using macromolecular porogens

Hydrophilic macroporous monolithic material based on poly(glycidyl methacrylate-co-glycerol dimethacrylate) was synthesized by photo-initiated free-radical polymerization. Different pore-forming agents, including low molecular mass cyclohexanol and dodecanol, as well as the solutions of hydrophobic polymers, namely, polystyrene in toluene and poly(dimethyl siloxane) in hexane, were used to obtain the macroporous polymer platforms intended for new type of 3-D microarrays (biochips). The porous characteristics of functional copolymers obtained were investigated by mercury intrusion porosimetry and scanning electron microscopy. Some of developed materials were tested for protein microarray construction. Demonstration of potential of suggested materials, as well as optimization of protein covalent immobilization conditions, were realized using model mouse IgG – goat anti-mouse IgG affinity pair.     

Effect of the nature of acrylic copolymers on the properties of latex composites for impregnation of textile materials

The effect of the monomer composition of acrylic latex copolymers on the physicomechanical properties and water resistance of films was investigated. Sorption of latex polymers by different fibres was studied. Latexes with the maximum sorption for Capron were selected. It was found that latexes synthesized with a low emulsifier content by methods of radiation and seed emulsion polymerization from films with high strength and water resistance. The promise of using latexes of this type for fabricating textiles of higher quality was demonstrated. __________ Translated from Khimicheskie Volokna, No. 2, pp. 15–17, March–April, 2006.     

Role of nanofiller in friction of polymers based on polycaproamide: Indirect effect

The effect of nanofillers (multiwalled carbon nanotubes) on the tribological behavior of polycaproamide is studied when introduced into the polymer by polymerization filling. The introduction of insignificant quantities (∼0.1 wt %) of nanotubes provides their homogeneous distribution in the polymer and contributes to reducing the wear and friction coefficient. This is mainly due to the role of nanotubes as nucleators of the fine spherulitic polycaproamide structure. Such an indirect effect of the nanofiller on the polymer’s tribological behavior is seen when nanotubes are added to the melt in the course of granulation of polycaproamide compositions reinforced by carbon fibers, the effect of nanotubes being reduced with increasing amount of the reinforcing filler.