Homogeneous polymer solutions are well known to exhibit viscoelastic flow instabilities: purely elastic when inertia is negligible and inertio-elastic otherwise. Recently, shear-banding wormlike micelle solutions were also discovered to follow a similar phenomenology. In the shear-banding regime, inertia is usually negligible so only purely elastic flows have been reported. Here, we investigate...

A novel type of high-pressure membrane reactor has been developed for hydrogenation in supercritical carbon dioxide (scCO(2)). The main objectives of the design of the reactor are the separate feeding of hydrogen and substrate in scCO(2) for safe reactions in a continuous flow process, and to reduce the reaction time. By using this new reactor, hydrogenation of cinnamaldehyde into hydrocinnamal...

This paper concerns maximal flows on Z traveling from a convex set to infinity, the flows being restricted by a random capacity. For every compact convex set A, we prove that the maximal flow Φ(nA) between nA and infinity is such that Φ(nA)/n almost surely converges to the integral of a deterministic function over the boundary of A. The limit can also be interpreted as the optimum of a determin...

General principles of supercritical fluid extraction technology to raise efficiency are summarized and concluded in this paper. It generalized the present domestic situation of relative research and developed proposals towards kind of charging and discharging continuous components by a new supercritical fluid extraction .It also introduced structures and working principles of device. Keywords— ...

Since deodorization distillate, a by-product of rice bran oil production, contains squalene (ca. 8%) and phytosterols (ca. 4%) as unsaponifiable components, the concentration of those materials for their use in the cosmetics and food industries is desirable. In the present work, a novel fractionation method of concentrating squalene and phytosterols from deodorization distillate or the unsaponi...

Direct numerical simulations of the transition process from laminar to chaotic flow in convergingdiverging channels are presented. The chaotic flow regime is reached after a sequence of successive supercritical Hopf bifurcations to periodic, quasiperiodic, and chaotic self-sustained flow regimes. The numerical experiments reveal three distinct bifurcations as the Reynolds number is increased, e...

A forced Korteweg–de Vries (fKdV) equation can be used to model the surface wave of a twodimensional water flow over a bump when the upstream Froude number is near one. The fKdV model typically has four types of solutions: sub-critical cnoidal waves, sub-critical hydraulic fall, transcritical upstream soliton radiation, and supercritical multiple solitary waves. This paper provides a numerical ...

A finite volume model was built upon earlier work with the aim of simulating free surface flows, pressurized flows and their simultaneous occurrence (mixed flows) in single-liquid and two-phase flow conditions (entrapment and release of air pockets). The model presented herein is based on a two-governing equation model. Three main contributions are presented herein, namely: (1) the ability of t...

The paper deals with the investigation of stability and nonlinear regimes of flow over the saturated porous medium applied to the problem of stability of water flow over the bottom covered with vegetation. It is shown that the velocity profile of steady plane-parallel flow has two inflection points, which results in instability of this flow. The neutral stability curves, the dependencies of cri...