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Abstract

Results of velocity measurements of liquid and gas bubbles in a tank with a self-aspirating disk impeller are analysed. Studies were carried out using a fluorescent dye tracer in the measuring system with two cameras (simultaneous phase velocity measurement) and with one camera (sequential measurement of phase velocity). Based on a comparative analysis of the acquired data it was found that when differences in the phase velocities were small the simultaneous velocity measurement gave good results. However, sequential measurement gives greater possibilities for setting the measuring system and if the analysis of instantaneous velocities is not necessary, it seems to be a better solution.
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Abstract

This paper presents a theoretical study of the propagation behaviour of surface Love waves in nonhomogeneous functionally graded elastic materials, which is a vital problem in acoustics. The elastic properties (shear modulus) of a semi-infinite elastic half-space vary monotonically with the depth (distance from the surface of the material). Two Love wave waveguide structures are analyzed: 1) a nonhomogeneous elastic surface layer deposited on a homogeneous elastic substrate, and 2) a semi-infinite nonhomogeneous elastic half-space. The Direct Sturm-Liouville Problem that describes the propagation of Love waves in nonhomogeneous elastic functionally graded materials is formulated and solved 1) analytically in the case of the step profile, exponential profile and 1cosh2 type profile, and 2) numerically in the case of the power type profiles (i.e. linear and quadratic), by using two numerical methods: i.e. a) Finite Difference Method, and b) Haskell-Thompson Transfer Matrix Method. The dispersion curves of phase and group velocity of surface Love waves in inhomogeneous elastic graded materials are evaluated. The integral formula for the group velocity of Love waves in nonhomogeneous elastic graded materials has been established. The results obtained in this paper can give a deeper insight into the nature of Love waves propagation in elastic nonhomogeneous functionally graded materials.
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Abstract

This paper deals with the phase-shift fault analysis of stream cipher Grain v1. We assume that the attacker is able to desynchronize the linear and nonlinear registers of the cipher during the keystream generation phase by either forcing one of the registers to clock one more time, while the other register is not clocked, or by preventing one of the registers from clocking, while the other register is clocked. Using this technique, we are able to obtain the full inner state of the cipher in reasonable time (under 12 hours on a single PC) by using 150 bits of unfaulted keystream, 600 bits of faulted keystreams and by correctly guessing 28 bits of the linear register.
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Abstract

Thermodynamic descriptions of the ternary Fe-B-V system and its binary sub-system B-V, are developed using experimental thermodynamic and phase equilibrium data from the literature. The thermodynamic parameters of the other binaries, Fe-V and Fe-B, are taken from earlier assessments slightly modifying the Fe-V description. The work is in the context of a new Fe-B-X (X = Cr, Ni, Mn, V, Si, Ti, C) database. The solution phases are described using substitutional solution model. The borides are treated as stoichiometric or semi-stoichiometric phases and described with two-sublattice models.
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