A theoretical analysis of the Saint-Venant one-dimensional flow model is performed in order to define the nature of its instability. Following the Brigg criterion, the investigation is carried out by examining the branch points singularities of dispersion relation in the complex ω and k planes, where ω and k are the complex pulsation and wave number of the disturbance, respectively. The nature ...

General principles of symmetry and conservation are used to construct the hydrodynamic equations for orientationally ordered suspensions of self-propelled particles (SPPs). Without knowledge of the microscopic origins of the ordering or the mechanisms of self-propulsion, we are able to make a number of striking, testable predictions for the properties of these nonequilibrium phases of matter. T...

The ion flux dynamics across a straight nanoslot is imaged to understand the nonequilibrium phenomenon of overlimiting current density across a nanoporous membrane. With a slow ac field, an ion-depletion front is generated intermittently from one end of the nanochannel, and a vortex instability first predicted by Rubinstein, Staude, and Kedem [Desalination 69, 101 (1988).10.1016/0011-9164(88)80...

Tropical cyclone (TC) tornado prediction remains a substantial challenge, both on its own and compared to advances made in prognostically relevant understanding of midlatitude supercells in particular. An ingredients-based approach (e.g., Johns and Doswell 1992), used for supercell tornado environments in midlatitudes, likewise can be applied to TCs, focusing on moisture, instability, vertical ...

Recent experimental observations have suggested key characteristics of internal transport barrier !ITB" formation near low-q surfaces in off-axis minimum-q !OAMq" discharges. These observations identify mean profile flattening localized to the low-q surface as a transition precursor in the absence of observable magnetic field perturbations. This observation suggests an electrostatic model of IT...

2014 Observation of the period doubling cascade in a Rayleigh-Bénard experiment in mercury. The experimental cell has an aspect ratio 0393 = 4 and contains four convective rolls. A DC magnetic field of 270 G is applied along the convective roll axis. The measured Feigenbaum number is 03B4 = 4.4. The ratio of the successive subharmonics is of the order of 14 dB for the lowest measured subharmoni...

Hadley cell simulations over a tropical ocean are reported which suggest that the emission and absorption of thermal radiation by clouds and moisture play a primary role in the dynamics of the Hadley circulation. In particular, inclusion of interactions between clouds and moisture on one hand and radiation on the other causes the tropical atmosphere to become unstable to large scale convective ...