Applications analysis of cartridge valves. The article introduces threaded cartridge hydraulic and application advantages in mobile hydraulic systems. Author presented the requirements for a right operation of cartridge valves and showed improvement trends of cartridge valves design.

Motion equations of pneumatic valve in air brake system. An authors presented the working principles of the two-circuit air brake system and formulates the differential equations of valve parts. The article is a part of a project which concerns mathematical modelling and simulation of the pneumatic multi-circuit systems. A developed software will be used in design and diagnosis of pneumatic systems.

An application of genetic algorithms in engineering. Evolutionary algorithms, including genetic ones, have more and more applications as very effective generators for solving and optimizing the design problems. Some technical applications such as developing assembly plan, designing pathways in printed circuit boards, specific robots, a low-pass filter and a regulator are suggested in this paper. A preliminary attempt to use them in designing hydraulic systems of low and medium degree of complexity is presented.

Defects in hydraulic systems of powered roof supports. The article describes phenomena occurred by extraction of coal from long wall in coal mine. Authors presented reasons of faults of hydraulic elements in roof supports and the prevention methods.