The study in this thesis focuses on the development of word-onset consonant clusters, in two-year-olds, acquiring Dutch. Word-onset clusters are often simplified during acquisition, but the... Show moreThe study in this thesis focuses on the development of word-onset consonant clusters, in two-year-olds, acquiring Dutch. Word-onset clusters are often simplified during acquisition, but the studies reported here demonstrate a more complex and diverse range of developmental possibilities. For example, reduced onset clusters were found systematically to contain an acoustic trace in the subsequent vowel; a seven-staged process of /Cr/ development in production was revealed. In perception longer looking times at toel (stoel) as opposed to tein (trein), evidenced for a more stable mental representation of correct /sC/ clusters. This phenomenon is studied from different perspectives. Both longitudinal and experimental data are studied, and experiments comprise both production and perception. In addition to phonological analyses, detailed acoustic analyses are performed. The speech production mechanism appears to develop in a top-down manner. The main error source for onset cluster productions is initially formed by incomplete segmental representations in the mental lexicon; with complete specifications, syllable spell-out at the phonological encoding level forms the main error locus. Phonetic encoding errors are the most persistent. Variable word forms are a hallmark of early child language; they show the relative instability of a new developmental state of the speech production mechanism. Show less
We study the interplay of topology and geometry with chirality for several passive and active systems, employing both analytical and numerical methods. In chapter 1, we explain how nematic liquid... Show moreWe study the interplay of topology and geometry with chirality for several passive and active systems, employing both analytical and numerical methods. In chapter 1, we explain how nematic liquid crystals confined in toroidal geometries undergo structural phase transitions depending on the slenderness of the confining toroid. In chapter 2, we consider a system of active polar swimmers that align with their neighbors. When confined in the right geometry, the system will self-assemble into a state with topologically protected chiral acoustic modes. The chirality in this system manifests itself as a temporal one, rather than a spatial chirality. Chapter 3 shows how systems of Yukawa charged active spinning dimers self-assemble into a crystal phase with spatiotemporal order, a liquid phase or a glass phase depending on the density. Depending on the phase and the confinement geometry of these systems of actively spinning dimers, the system will allow for rigid body rotations or edge currents. Finally, in chapter 4 we introduce a novel method of doing molecular dynamics on curved surfaces by developing a symplectic integrator. We present preliminary results on two-dimensional crystal melting in the presence of curvature. We find that the crystal may melt inhomogeneously. Show less