A study of the detection accuracy of proportional chambers with cathode read-out

Results are presented of a study of the accuracy in detecting relativistic particle coordinates in proportional chambers using the cathode information read-out. The width of the cathode strips was 2 mm and the anode to cathode distance 4 mm. For the tracks perpendicular to the chamber plane the detection accuracy was 50 μm. Two methods of calculation of the centre of the induced charge distribution on the cathode strips are described: by the centre of gravity and by fitting this distribution by a special formula. It is shown that for single-particle events the change of the width of the induced charge distribution does not exceed 1.2%.     

3-D x-ray strain microscopy in two-phase composites at submicron length scales

Renewed interest in composite materials is driven by the fact that their mechanical properties can be superior to those of individual constituent phases. Interfaces between the phases and the properties of individual phases are the two key elements responsible for the unique micro-mechanisms of plastic deformation in composites. In this research summary we show how the depth-dependent residual strain distributed in the two phases and partitioned across the composite interfaces can be directly measured at submicron length-scales using x-ray microdiffraction and compared to a detailed simulation within the framework of micromechanical stress analysis. Interface strength is determined from the analysis of the so-called “slip zone” caused by the near-surface stress relaxation. Two examples are discussed: Mo-NiAl and AG-15 composites.     

Influence of Deformation and Heat Treatment on the Microstructure and Properties of High-Strength Low-Alloy Steel with Boron

The microstructure, fine structure, and mechanical properties of high-strength low-alloy steel with boron are studied after two different rolling technologies: (1) high-temperature hot rolling; (2) two-stage controlled rolling with accelerated cooling and subsequent quenching with tempering. The tempering temperature corresponding to irreversible tempering brittleness of the first kind is established. The reasons for embrittlement at that temperature are analyzed.     

The bonding strength of powder coatings in gas-flame spraying with the hydrogen–oxygen flame

The equipment, procedure and the results of investigations of the bonding strength of gas-flame coatings with the substrate are described. The dependence of the bonding strength on the conditions of spraying with the powder materials using the hydrogen–oxygen flame is outlined.     

Influence of salivary kallikreins on microvessels of the hamster cheek pouch and rat mesentery

By means of in vivo microscopy the influence of human, rat, and hamster purified salivary kallikreins upon the microvessels was studied in rat mesentery and hamster cheek pouch. Dilatation of arterioles, a decrease of the venule diameter, and an increase in the number of active capillaries was revealed. The species and organ peculiarities of these effects were described. The mesentery and the cheek pouch homogenates, albumin proteins, histamine and some amino acids were capable of activating the salivary kallikreins.     

Scanning laser system for combined fluorescent diagnostics andphotodynamic therapy: structural design, preliminary trials, andpotentials

Photodynamic therapy (PDT) is commonly performed by administration of porphyrin photosensitizers selectively retained by malignant tumors. Subsequent photoexcitation with UV-blue light causes fluorescence useful for diagnosis. Excitation by red light destroys the cancer tissue. The use of high-speed scanning of laser light as an alternative to conventional PDT which employs dispersed light to achieve uniformity of treatment is proposed. It is shown that treatment with scanned light beams produces photochemical effects in malignant animal tissue that are virtually the same as those caused by comparable treatments with diffused light. It is argued that undesirable thermal effects can be reduced by the use of focused, scanned laser beams in lieu of diffused light. It is also shown how concurrent analysis and treatment can proceed using a system of two laser beams