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Abstract. We study Faraday and resonant waves in two-component quasi-onedimensional (cigar-shaped) collisionally inhomogeneous Bose-Einstein condensates subject to periodic modulation of the radial confinement. We show by means of extensive numerical simulations that, as the system exhibits stronger spatially-localised binary collisions (whose scattering length is taken for convenience to be of Gaussian form), the system becomes effectively a linear one. In other words, as the scattering length approaches a delta-function, we observe that the two nonlinear configurations typical for binary cigar-shaped condensates, namely the segregated and the symbiotic one, turn into two overlapping Gaussian wave functions typical for linear systems, and that the instability onset times of the Faraday and resonant waves become longer. Moreover, our numerical simulations show that the spatial period of the excited waves (either resonant or Faraday ones) decreases as the inhomogeneity becomes stronger. Our results also demonstrate that the topology of the ground state impacts the dynamics of the ensuing density waves, and that the instability onset times of Faraday and resonant waves, for a given level of inhomogeneity in the two-body interactions, depend on whether the initial configuration is segregated or symbiotic.

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Motivated by the advent of security solutions which rely on voice biometrics, we revisit by means of extensive computer-based investigations the concept of phonetical balance for Romanian utterances. We show that the standard distribution of phonems offers only a partial description of the phonetics of the language and that more detailed statistical indicators are needed. To this end, we introduce a simple indicator that measures vowel-consonant (or consonant-vowel) sequences and analyze the distribution of consonant clusters for Romanian words. Our results show that the distribution of consonant clusters is scalefree-like (akin to the distribution of words and phrases in large texts) and that large clusters of vowels or consonants are infrequent. This, in turn, indicates that utterances consisting of words which are statistically unrepresentative with respect to the previous indicators are good candidates for benchmarking the efficency of voice biometrics solutions.

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