Interrelations Between Different Forms of Group Variability of Quantitative Traits in Microtus socialis (Cricetidae, Mammalia) in the Peak Phase of Population Abundance

Проведено исследование величины вкладов и соотношения разных форм групповой изменчивости количественных признаков в общем морфологическом разнообразии M. socialis в фазе пика численности популяции. Показано, что изменчивость 4 экстерьерных и 11 интерьерных признаков определяется, прежде всего, возрастом животных и в меньшей степени полом и сезоном. С возрастом полевок выраженность половых различий и сезонной изменчивости увеличивается. Коррелированная изменчивость признаков практически одинакова (Rs = 0,820–0,98) у самцов и самок разных сезонов.The amount of input and the interrelation of various forms of group variability of quantitative traits in general morphological disparity of M. socialis in the peak phase of the population abundance was studied. It was found that the variability of 4 exterior and 11 interior traits are determined primarily by the age of the animals, whereas the influence of sex and the season is very low. With ageing, the intensity of sexual differences and seasonal variability increase. The correlated variability of morphological traits was almost the same (Rs = 0.820—0.98) in males and females during different seasons

Dynamics and combustion of single aluminium agglomerate in solid propellant environment

Aluminized composite propellant used in solid rocket motors contain a lot of aluminium particles because high combustion energy is generated and propulsion efficiency increases by burning aluminium particles. The combustion of aluminum occurs in a significant portion of the combustion chamber and produces aluminum oxide smokes and residues that are carried into the flowfield. Agglomerates have non-spherical shape, and consist of aluminium droplet and oxide particle (oxide cap) attached to the droplet. Unlike the liquid droplet ignition, the solid oxide film blocks the liquid aluminum from the penetration of the oxidizer hence prevents the particle from its ignition. Development of robust models of aluminum particle dynamics is essential in the design of advanced propulsion systems. The mathematical model of two-phase flow around a single aluminum droplet with oxide cap is developed. The model solves the continuity, momentum, energy and species continuity equations simultaneously to obtain the species and temperature profiles and the burning time of droplet. The results of numerical simulations are compared with predictions from semi-empirical correlations and computational data

Flows of real gas in nozzles with unsteady local energy supply

When gas flows at a high speed in a channel with a variable cross sectional area and high-intensity energy supply, it experiences complicated physical and chemical processes producing high-temperature gas effects. High-temperature gas effects are a key issue related to design and optimization of nozzles of plasmatron of alternating current. The finite volume method is applied to solve unsteady compressible Euler equations with high-temperature gas effects. Solutions of some benchmark test cases are reported, and comparison between computational results of chemically equilibrium and perfect air flowfields is performed. The results of numerical simulation of one-dimensional and two-dimensional under- and over-expanded nozzle flows with a moving region of energy supply are presented. Output nozzle parameters are calculated as functions of a number and time of burning of plasmatron arcs. The results obtained show a qualitative pattern of gas dynamics and thermal processes in the nozzle with unsteady energy supply demonstrating the displacement of the nozzle shock wave towards the nozzle outlet in the over-expanded nozzle flow in comparison to perfect gas flow