Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

We show the distribution of SARS-CoV-2 genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three available genomic nomenclature systems for SARS-CoV-2 to all sequence data from the WHO European Region available during the COVID-19 pandemic until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation. We provide a comparison of the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2.Peer reviewe

MATHEMATICAL MODEL OF FORMATION OF NOISE OF VIBROSHOCK HARDENING OF LONGERONS OF HELICOPTERS

In article the mathematical model of formation of noise of the stand of vibroshock hardening of longerons of helicopters is resulted. Power methods speeds of fluctuations of separate subsystems and bearing system as a whole pay off. Dependences of vibrating capacity entered from a working environment in walls of containers are received that essentially specifies the theory of calculation of noise of the similar equipment

FLAW'S RECONSTRUCTION IN MULTI-LAYERS COMPOSITES

There are offered methods of faults reconstruction in stratified composites - stratifications (the interface flaws). Inverse geometrical problems of reconstruction of flaws are reduced to a solution of sequence of systems of the BIE obtained on the basis of reciprocity theorem of operations at established oscillations of expert samples. Solution BIE will be carried out on the basis of a combination of FEM, a method of BEM and a method of a regularization of A.N.Tihonov. As the additional information for a solution of inverse problems the field of displacement measured on a part of exterior boundary of a skew field, free from mechanical stress. Numerical examples of identification of stratifications and ruptures surveyed within the framework of a flat problem of theory of elasticity

POLYMERIC COMPOSITE ELASTIC CONSTANTS DETERMINATION ON THE BASIS OF MODIFIED TECHNIQUE. THEORETICAL & NUMERICAL ANALYSIS

The V-notch (standard ASTM D5379-93) shear test was investigated for determining the in-plane shear modulus. With purpose of lateral response exception the new scheme of test with specimen symmetrical loading is offered. For standard and modified schemes the comparative finite element analysis of state in a specimen's working area is executed. This analysis allow to determine the shape and sizes of a pure shear zone at different orientations of reinforcing fibers and geometrical tolerances, and to estimate error in determination of a shear modulus stipulated by averaging of shear stresses in specimen's working section. The results have shown full coincidence of stress-strained states at standard and modified schemes of tests. Our numerical evaluation shows that even for specimens with ideal shape using of mean shearing stress (relation of an applied force to a sectional area between notches) always increase error of shear module determination more than 15 % and for obtaining more precise results it is necessary to padding definition of shear stresses in center of a working area with FEM analysis. For using in actual experiment, when there are geometrical errors of the shape and fastening of specimens, but the remaining modules are determined irrespective of considered tests, the effective iterative scheme on the FEM based numerical experiment for refinement and for definition of a shear modulus values confidence interval is offered