We describe aspects of particle creation in strong fields using a quantum kinetic equation with a relaxation-time approximation to the collision term. The strong electric background field is determined by solving Maxwell’s equation in tandem with the Vlasov equation. Plasma oscillations appear as a result of feedback between the background field and the field generated by the particles produced...

The inspiratory phase of the respiratory rhythm involves the synchronized bursting of a network of neurons in the brain stem. This paper considers activity patterns in a reduced model for this network, namely, a system of conductance-based ordinary differential equations with excitatory synaptic coupling, incorporating heterogeneities across cells. The model cells are relaxation oscillators; th...

Numerical simulations of sawteeth in tokamaks have been carried out using reduced magnetohydrodynamics and a simple transport model. The electron temperature is evolved self-consistently, including Ohmic heating and a highly anisotropic thermal diffusivity. The sawtooth period and collapse time found in the simulations for Lundquist numbers S below 10 compare favourably with experimental result...

The behaviour of a system composed of malonic acid (MA), KBrO3, H2SO4, and ferroin was investigated in batch experiments at various concentrations of oxygen above the chemical mixture when changing the concentration of MA. We could observe that at 10% of oxygen or more and for initial concentrations of malonic acid [MA]0 between 0.15 M and 0.6 M the system attains an equilibrium by some of mixe...

ANDREW ROBERTS: Abrupt changes and intervening oscillations in conceptual climate models (Under the direction of Christopher K.R.T. Jones) This thesis examines the role of fast/slow dynamics in understanding the mechanisms behind oscillatory patterns found in paleoclimate data. Fast/slow systems often exhibit rapid transitions between metastable states, and understanding these transitions is im...