In this paper a small time local controllability, naturally defined in a configuration space, is transferred into a task-space. It was given its analytical characterization and practical implications. A special attention was put on singular configurations. Theoretical considerations were illustrated with two calculation examples. An extensive comparison of the proposed construction with the controllability defined in an endogenous configuration space approach was presented pointing out to their advantages and disadvantages.

The article presents the results of research on the formation of the WF coefficient in coal excavations. The WF coefficient determines the share of the wet surface of the excavation sidewall. The wet part of the excavation sidewall is covered partly by the water film, which evaporates, lowering the temperature of this surface. This coefficient is one of the principal parameters used in forecasting the changes in temperature and humidity of the mine air occurring on the way of contact between the excavation sidewall and the flowing air. During the determination of the coefficient value, the criterion of equality of the actual and forecasted ratios of sensible heat to total heat was assumed in the research methodology. Values of the WF coefficient in the examined excavations generally vary within the range of 0,1-0,6, and they are mostly dependent on the parameters related to the period of ventilation.

The article presents the context‑determinated meanings of the дурак (durak) lexem based upon the satirical sketches Well‑Meant Speeches by Mikhail Saltykov‑Shchedrin. At the beginning is the etymology of the word and then general vocabulary definitions produce four basic meanings for the word: 1. a good and honest man; 2. a person being the object of widely‑spread mockery and jibes; 3. a person unable to behave in a proper way; 4. a person unable to administer their property in a good way as well as not to live their life successfully – a lame duck, a sluggard and a drunkard. From amongst those meanings the author tries to notice the mutual parallels which interpret visions of the fool in Saltykov‑Shchedrin’s sketches as well as the contemporary vision of the Russian mentality and its folk tradition.