One of the promising working units for pre-sowing soil preparation, in particular, for pre-sowing soil cultivation for potatoes, are still the disk tillage. Studies of a number of authors determined, that the disc units with continuous cutting edge are more energy intensive, less resistant to running and sensitive to changes in the load and working units with a serrated cutting edge has significant advantages. However, not all gear working units are able to perform advanced agronomic requirements. The rational parameters of developed by the working units, can only be determined on the basis of a study of the process of its interaction with the soil, but in relation to working units with a serrated cutting edge, this question is poorly understood. Working unit movement with respect to the adopted reference system, can be regarded as fully qualified only, when we know the movement of its each points in the same frame of reference. Therefore, the disk working unit is considered a with the teeth, the cutting edge of which is made by a logarithmic spiral curve, providing moving cutting of soil and plant remains in motion, and the back edge is in a straight line, connecting the toe of each tooth with the center of the disk. As a result of calculations, based and the equations of motion for an arbitrary point of the cutting edge of a tooth of a flat disk of the working unit, which allows to build a trajectory in space, determine the velocity and acceleration of the blade points at any given time.

The article shows the limited capacity of the traditional (passive) suspension systems to meet the constantly increasing requirements imposed on modern motor vehicles, as well as the expediency of application of controlled suspension systems. Modeling of processes in the system with the electromagnetic compensator stiffness in the free vibration mode in the software package Matlab Simulink.

The article cites the results of studies to identify the influence of form identity of Siberian cedar (according to the form of cones and seed scale apophysis type) on the index of seed productivity. It was noted the link presence between forms. The authors proposed to use the differences by type of apophysis for breeding purposes.