Tremors occur randomly in terms of time, energy as well as the location of their focus. The present state of knowledge and technology does not allow for the precise prediction of these values. Therefore, it is extremely important to correctly select a powered roof support for specific geological and mining conditions, especially in the case of areas where dynamic phenomena are often registered. This article presents information on rock burst hazard associated with the occurrence of rock mass tremors and their influence on a powered roof support. Furthermore, protection methods of a powered roof support against the negative effects of dynamic phenomena are discussed. As a result of an analysis the methodology, to determine the impact of dynamic phenomena on the powered roof support in given geological and mining conditions is presented.

The article analyzes the letters of L. Dobychin from 1924-1936. It reveals the main characteristics of the images of the author and the addressee, explicit and implicit forms of the author’s self-expression, the author’s epistolary intentions. The article shows that for Dobychin letters are not only external, but also internal representant of a personality, the most important way of formation of the image of “I” in its subjective and objective significance. The uniqueness of the author’s epistolary personality is determined by absolute sincerity and uncompromising judgment, etiquette pedantry, the combination of ironic and sentimental intonations, acute experience of his relations with the world and people, idealization of writerly status, orientation to the ideal norm both in aesthetic and in behavioral sense. The image of the addressee of the letters is partly mythologized and determined by the type of relationship between the correspondents and the role chosen by the addressee. The variations of the author’s “ego” and the change of the addressees’ role functions provide an expansion of the semantic and aesthetic potential of the image of the addressee and the correspondence as a whole.