Search academic texts

Information × Registration Number 0224U000157, 0121U112687 , R & D reports Title Fulfillment of tasks of the perspective plan of development of a scientific direction "Mathematical sciences and natural sciences" Sumy State University popup.stage_title Head Pohrebniak Oleksandr D., д.ф.-м.н.Protsenko Ivan Yu., Доктор фізико-математичних наукKhomenko Oleksiy Vitaliyovych, Доктор фізико-математичних наук Registration Date 03-01-2024 Organization Sumy State University popup.description2 The development of modern technologies constantly directs the solution of new physical and technical problems faced by man. One such problem is ice friction, which has both a practical experience of human interaction (such as driving on ice) and natural aspects (such as the movement of glaciers). In everyday life, the simulation of ice friction is useful for humans in the study of processes in the design of artificial ice environments, such as the effect of glacier movement on climate, as well as in the study of various materials and components that move on ice, for example, in the creation of elements and structures in mechanical engineering and winter sports. The model is represented by a system of three one-dimensional partial differential parabolic equations. In this model, the friction forces are given by the film's viscosity and thickness, which are determined by the combined effect of melting and pressure on the ice surface. According to this approach, frictional heating changes friction due to thermal softening of the surface or the formation of a heterogeneous thin surface film consisting of spatially and temporally variable crystals and areas of softened ice. We explain why ice friction decreases with increasing sliding speed, reaching a value at which a thin, homogeneous layer of water forms on the surface. Free electron lasers (FELs) are powerful sources of electromagnetic radiation in the terahertz range in various fields of human activity, such as remote gas monitoring, medical examination, imaging, public safety, etc. One of their main advantages is the convenient setting of the radiation frequency in a wide range and the creation of powerful output signals. However, it should be noted that these devices have certain disadvantages, the main of which are the large size and the complexity of the construction, which ultimately limits the scope of their use. Therefore, recently researchers have focused on improving existing schemes of such devices and cre Product Description popup.authors Ilin Stanislav S. Badalyan Anna Yu. Lysenko Oleksandr V. Lohvynenko Denys T. Poroskun Olena Khomenko Oleksii V. Chernushchenko Roman R. Shykura Oleksii Yu. popup.nrat_date 2024-01-03 Close