Research features of voltage static load characteristics in the electric system of Russia
At the present time using the standard (generalized) voltage static load characteristics which can differ from actual considerably is provided in software packages for calculations of the steady-state mode and steady-state stability (in the absence of exact data). Absence of the metering or the incorrect metering of the actual voltage static load characteristic, and also using the standard (generalized) static load characteristics could lead to considerable errors and the incorrect final results while making calculations. The definition experience of actual voltage static load characteristics in different ways made by authors is given in this paper: making tests in situ in electric power systems by allocation of energy area load or separately taken electric power substation to the isolated electric supply, load allocation of the power supply from the power plant generator; registration data using of crash conditions of the electric power system. Such test of actual voltage static load characteristics definition in electric system of Russia it is reduced by authors in making tests in situ technique. Error estimation which can appear in calculations of steady-state modes with the absence of the voltage actual load characteristics is executed.
GLOBAL CLIMATE CHANGE AND RISKS OF ARCTIC ACTIVITIES
The Arctic region plays a crucial role in climate management in other parts of the world. Global warming and climate change affect the state of many natural ecosystems and thus-the state of the biosphere as a whole, the biosphere conditions of human existence. The article was analyzed the sources of risks of polar regions due to the warming of the Arctic climate. Modern scientific research related to climate change, which is the determining cause of the warming of the Earth’s climate are analyzed. Climate change caused by the industrial development of mankind has taken place too quickly over the past 100 years, and modern society can no longer ignore this problem. There is a risk of further increase in average temperature, so, by 2050, a special danger is the destruction of ice sheets. The author highlighted the risks affecting climate change and among them CO2 is the main anthropogenic factor caused by the burning of fossil fuels. Measures are proposed to solve the problem to continue the sustainable development of the Arctic territories and reduce the degree of risk.
Mechanics of deformable directed surfaces
Abstract The paper develops a simple, yet complete and consistent non-linear dynamic thermo-elastic shell theory based on the concepts of a two-dimensional directed continuum. The constitutive equations are postulated in a general form. Stress-strain relations are derived using the equation of energy balance and the two entropy production inequalities, which are rewritten in a special form. The linear theory is discussed in detail. The structure of the stress-strain relations is presented in the most general form and then specialized to concrete examples, in particular, to the classical shell theory, using their invariance properties with respective to certain symmetry groups. The elastic moduli are determined by demanding the coincidence of the frequency dispersion surfaces obtained using the two-dimensional theory with the lowest foils of the corresponding surfaces resulting from the three-dimensional theory of elasticity.