Marchantinquinone, isolated from Reboulia hemisphaerica, as inhibitor of lipid peroxidation and as free radical scavenger

Recent years have witnessed a renewed interest in plants as pharmaceuticals in the Western world. This interest is channeled into the discovery of new biologically-active molecules by the pharmaceutical industry and into the adoption of crude extracts of plants for self-medication by the general public. In both of these areas some attention is being paid to the investigation and use of ethnopharmacology, the traditional use of plants for medicinal purposes by particular cultural groups. Ethnopharmacologic leads have resulted in the introduction of new single molecule drugs but have a greater role to play if crude extracts are accepted for clinical use in the West. The problems confronting such usage are discussed. Considerable benefits for developing countries are possible when the local medicinal plants are subjected to scientific methods of validation of traditional use and quality control. This approach has met with success in some parts of the world but is not always appreciated by national governments and international agencies. Related areas of concern such as conservation of ecology and culture must be integrated with any such program. Plants used in traditional medicine therefore have an important role to play in the maintenance of health in all parts of the world and in the introduction of new treatments.     

Energy-Saving Technology of Assorted Glassware Decoration by Plasma Spraying

Glass and Ceramics - An energy-saving technology for decorating assorted glassware by plasma spraying of colored assorted and container glasses was developed. The optimal spraying parameters for...     

Composite material in the aluminum oxide-zirconium dioxide system

A dispersion-hardened material with average flexural strength 580 ± 40 MPa, which is a promising building material, has been fabricated by introducing a CaO-ZnO-Al₂O₃-SiO₂ eutectic additive and tetragonal zirconium dioxide into aluminum oxide synthesized by calcining the hydroxide. The sintering temperature of this ceramic is 1550°C. The properties of the eutectic of this system are analyzed, and the optimal liquid-phase composition which gives intense sintering of the aluminum oxide is determined. __________ Translated from Steklo i Keramika, No. 4, pp. 12–15, April, 2007.     

Analysis of corundum ceramics strength

Based on 50 compact and porous corundum materials with sintering additives, the dependence of the material strength on the strength of the interparticle contactsP, the interlayer thicknessh, the particle sized, and the amount of additive is analyzed. A linear dependence ofP ond for porous materials and a quadratic dependence ofP ond ² for compact materials are established. It is shown that the parameterP is more sensitive to the structural parameters of the material than the material strength. Translated from Steklo i Keramika, No. 5, pp. 26 – 29, May, 1999.     

Energy saving for steelmaking in plasma-arc furnaces

A design for a plasma-arc steel-melting furnace with four plasma generators and a rational method for steelmaking, which can decrease the heat time and the electric energy consumption, are pro- posed. The rational arrangement of wall plasma generators in the liquid stages of a heat are determined by analytical investigations.     

The use of thiosemicarbazyde in the pressure-driven processes of wastewater teatment

We have investigated the possibility of using thiosemicarbazyde as a complexation agent when conducting pressure-driven purification o solutions obtained at chemical treatment of the surface of metals. The concentration of Fe³⁺ and Cu²⁺ in the initial solutions is determined by the standard preliminary purification of wastewaters at the level 70 mg/dm³. It was found that the optimal concentration of the complexation agent constitutes 10 mg/dm³.     

Behavior of pearlite of various morphologies during cyclic tension

The structural evolution of hypereutectoid U10 steel with a pearlitic structure of various types (fine lamellar or partly spheroidized pearlite) is studied during fatigue loading. The fracture of these structures is considered using fractography data. The specific features of the structural transformations and the changes in the dislocation structure of the U10 steel are revealed during cyclic tension in the high-cycle fatigue region at a significant distance (10 mm) from a fatigue fracture surface. Substantial structural changes are shown to occur in U10 steel with various pearlitic structures during high-cycle fatigue tests (tension at a stress amplitude in a cycle lower than the macroscopic yield strength). These are the fragmentation, partial dissolution, and spheroidization of cementite lamellae and the polygonization of the ferrite component. The relationship between the type of fracture surface and the type of structure formed upon fatigue loading is found.