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In this study, one normal subject and two patients suffering from a cerebral aneurysm with circular and elliptical necks are analyzed by using the fluid-structure interaction (FSI) method. Although the blood hemodynamic parameters increase after the occurrence of the disease, the largest increase is in the wall shear stress (by a factor of 4.1-6.5) as compared to the normal subject. The increase in these parameters for patients with a circular neck is more pronounced than that with an elliptical neck. The blood flow becomes slightly more turbulent after the occurrence of the cerebral aneurysm, though it still remains in the range of the laminar flow and the pulsatility of the blood flow in patients is 28-45% greater than that of the normal subject. Finally, the results show that the risk of vessel rupture in the cerebral aneurysm with a circular neck is 40.8% higher than that in the case of the cerebral aneurysm with an elliptical neck.

Results of a numerical analysis of the dynamic behavior of a compressed magma melt in a slot channel with gradual opening of the diaphragm and results of simulations of its time evolution are reported. The Iordanskii-Kogarko-van Vijngaarden mathematical model of a two-phase medium and a model that describes phase changes in the gas-saturated plasma behind the front of the decompression wave being formed are used. Results of numerical simulations of the flow with allowance for specific features of the pressure dynamics in the decompression wave, mass velocity components, volume fraction of the gas phase, and its viscosity are presented.

The problem of the vibrations of an ice sheet with a rectilinear crack on the surface of an ideal incompressible fluid of finite depth under the action of a time-periodic local load time is solve analytically using the Wiener-Hopf method. The ice sheet is simulated by two thin elastic semi-infinite plates of constant thickness. The thickness of the plates may be different on the opposite sides of the crack. Various boundary conditions on the edges of the plates are consudered. For the case of contact plates of the same thickness, a solution in explicit form is obtained. The asymptotics of the deflection of the plates in the far field is studied. It is shown that predominant directions of wave propagation at an angle to the crack can be distinguished in the far field in the case of contact of two plates of different thickness. In the case of contact of identical plates, a edge waveguide mode propagating along the crack is excited. It is shown that the edge mode propagates with maximum amplitude if the vertical wall is in contact with the plate. Examples of calculations are given.

A thermal model of the aluminized polymer shell of a gauge-adjusting satellite for calculating the steady-state temperature distribution of this shell at its fixed orientation relative to the Sun. A modified version of the model was used to analyze the quasistationary distribution of the shell temperature in the case of its rotation with a constant angular velocity about an axis perpendicular the direction to the Sun.

This paper presents a study of the self-excitation of thermomechanical self-oscillations of a current-carrying conductor which depend on its electrical resistance, power of joule heat release, and the heat transfer from its surface. The conditions for the occurrence of self-oscillations are determined, and numerical simulation of the excitation of oscillations is performed.

The problem of simulation of electrochemical treatment by reduction to a solution of a Schwartz problem on a parametric rectangle via theta functions is solved. Various conditions are considered (nonequipotentiality of electrodes and inconsistent current output) at the boundary of the surface treated. Nonstationary, quasistationary, stationary, and limiting solutions are presented. The results of surface treatment with tool electrodes of various shapes are given. It is shown that the parameters of the processing mode significantly affect the allowance necessary to achieve highly accurate copying.

The effects of the end conditions of cross-ply laminated composite beams on their dimensionless natural frequencies of free vibration is investigated. The problem is analyzed and solved by using the energy approach, which is formulated by a finite element model. Various end conditions of beams are used. Each beam has either movable ends or immovable ends. Numerical results are verified by comparisons with other relevant works. It is found that more constrained beams have higher values of natural frequencies of transverse vibration. The values of the natural frequencies of longitudinal modes are found to be the same for all beams with movable ends because they are generated by longitudinal movements only.

Natural convection heat transfer from a vertical isothermal plate with pin fins is numerically studied by solving the Navier-Stokes equations along with the energy equation. The average Nusselt number for the plate with different configurations of pin fins is obtained. The average Nusselt number is found to increase with increasing aspect ratio of the fin and to decrease with increasing angle of fin inclination with respect to the plate. There is only a minor difference between the average Nusselt numbers for in-line and staggered arrangement of fins for the range of parameters studied in the present work. A correlation is developed to predict the average Nusselt number of the plate as a function of fin spacing in the streamwise and spanwise directions, aspect ratio of the fin, and its angle of inclination.

This paper describes a method for determining the strain state of a thin anisotropic plate with elastic arbitrarily arranged elliptical inclusions. Complex potentials are used to reduce the problem to determining functions of generalized complex variables, which, in turn, comes down to a undetermined system of linear algebraic equations, solved by singular expansions. This paper presents the results of numerical calculations that helped establish the influence of rigidity of elastic inclusions, distances between inclusions, and their geometric characteristics on the bending moments occurring in the plate. It is certain that the specific properties of distribution of moments near the apexes of linear elastic inclusions, characterized by moment intensity coefficients, occur only in the case of sufficiently rigid and elastic inclusions.

This paper describes the results of an experimental study on deformation and fracture of a Zr - 1% Nb zirconium alloy in the case of multiple loads at low temperatures (-80^oC). Samples cut out of pipes and applied as fuel rod shells of heat releasing assemblies of nuclear reactors are used to conduct a series of experiments on low-cycle stretching and compression at low temperatures and study the effect of low temperature on stress relaxation in the material under a different number of preliminary loads.