The influence of the hold time of the austempering heat treatment at 280°C on the microstructure and corrosion resistance in NaCl-based media of austempered ductile iron was investigated using X-ray diffraction, micro-hardness measurements, corrosion tests and surface observations. Martensite was only found in the sample which was heat treated for a short period (10 minutes). Corrosion tests revealed that this phase does not play any role in the anodic processes. Numerous small pits were observed in the α-phase which is the precursor sites in all samples (whatever the value of the hold time of the austempering heat treatment).

Sintered ore used as blast furnace burden materials is produced by mixing iron ore, coke, and limestone, then burning the coke and sintering the iron ore with the combustion heat. Among the coke charged, A particle size of 0.25 mm or less has an insignificant effect as a heat source and adhere to the surface of other materials to inhibit the reaction between oxygen and raw materials, thereby decreasing the quality of sintered ore. Therefore, to increase combustion efficiency, it is necessary to reduce the ratio of coke breeze in the charged coke.
In this study, theoretical calculation, experiment and simulation were conducted to investigate the possibility of size classification by drag force in the process of dropping coke after being transported through a belt conveyor. The height of belt conveyor was at 1m, and velocity of the belt was 1.5, 2.3, and 2.6 m/s, which were considered as experimental variables. After falling, the distribution of coke particle size according to the horizontal travel distance was confirmed, and a fall trajectory prediction formula model was created through the drag model of polydisperse system and compared with the experimental and analysis results.

In recent years organic semiconductors have been given attention in the field of active materials for gas sensor applications. In the paper the investigations of the optoelectronic sensor structure of ammonia were presented. The sensor head consists of polyaniline and Nafion layers deposited on the face of the telecommunication optical fiber. The elaborated sensor structure in the form of Fabry-Perot interferometer is of the extremely small dimension – its thickness is of the order of 1 um. Many sensor structures of diffierent combinations of the polyaniline and Nafion layers were constructed and investigated. The optimal solution seems to be the structures with small number of polianiline layers (up to three).