A Gradient Harmonic Grammar Account of Nasals in Extended Phonological Words

The article aims at contributing to the long-standing research on the prosodic organization of linguistic elements and the criteria used for identifying prosodic structures. Our focus is on final coronal nasals in function words in Greek and the variability in their patterns of realization before lexical words. Certain nasals coalesce before stops and delete before fricatives, whereas others do not. We propose that this split in the behavior of nasals does not pertain to item-specific prosody because the relevant strings are uniformly prosodified into an extended phonological word (Itô & Mester 2007, 2009). It rather stems from the contrastive activity level of nasals in underlying forms in the spirit of Smolensky & Goldrick’s (2016) Gradient Symbolic Representations; nasals with lower activity coalesce and delete in the respective phonological environments, whereas those with higher activity do not. We show that the proposed analysis captures certain gradient effects that alternative analyses cannot account for.

Classification of Spatio-temporal Patterns in Charging and Discharging of Li-ion Batteries

We classify the dynamic patterns that emerge in charging or discharging of Li-ion batteries, under galvanostatic conditions, using simulations of the two-phase 1D porous model. This work examines the effect of exchange current function, R0(X), which expresses the nature of kinetics and extends our previous study limited to R0=1 for which the same pattern emerges, whether homogeneous or step-wise process made of multiple symmetry breaking events. With the commonly-used asymmetric R0(X) the emerging pattern may be one of the two above or fronts that follow single SB event and lithiation/delithiation behaviors are different. These effects are clear when parameters are uniform; non-uniformity leads to noise that mask the behavior. The full 4-variable model exhibits SB, even in absence of noise, since the liquid potential gradient ( ) works like a perturbation. Similarity between noise and gradient effects allows us to derive approximations to full model behavior, and study various effects.

Slow oxidation of magnetite nanoparticles elucidates the limits of the Verwey transition

Magnetite (Fe3O4) is of fundamental importance for the Verwey transition near TV = 125 K, below which a complex lattice distortion and electron orders occur. The Verwey transition is suppressed by chemical doping effects giving rise to well-documented first and second-order regimes, but the origin of the order change is unclear. Here, we show that slow oxidation of monodisperse Fe3O4 nanoparticles leads to an intriguing variation of the Verwey transition: an initial drop of TV to a minimum at 70 K after 75 days and a followed recovery to 95 K after 160 days. A physical model based on both doping and doping-gradient effects accounts quantitatively for this evolution between inhomogeneous to homogeneous doping regimes. This work demonstrates that slow oxidation of nanoparticles can give exquisite control and separation of homogeneous and inhomogeneous doping effects on the Verwey transition and offers opportunities for similar insights into complex electronic and magnetic phase transitions in other materials.

Microscale size effects in piezomagnetic material for the anti-plane problem

A continuum model of piezomagnetic material with strain, magnetic and piezomagnetic coupling gradient effects is proposed using a variational principle in this work. This model is employed to an anti-plane problem, and a general solution is constructed in polar coordinates. Special attention is paid to microstructural effects on the magnetic and mechanical response in an infinite piezomagnetic medium with a void. It is found that the microstructural length scales have a significant influence on the mechanic and magnetic fields. The three length scales (corresponding to strain, magnetic and piezomagnetic coupling gradients) are indispensable to describe the nonlocal effects of piezomagnetism. Additionally, controlling the direction and magnitude of the magnetic field at the edge of the void can be achieved by adjusting the microstructural length scales of the piezomagnetic medium.