purpose: to investigate the results of deep lamellar keratoplasty (dlk) by big bubble method with using shifting bubble sign in patients suffering from keratoconus or corneal opacity methods: in this prospective interventional clinical trial, 20 eyes of 18 patients (10 males and 8 females) who underwent dlk by big bubble method using shifting bubble sign were investigated. mean age of cases wer...

Compressible large-eddy simulations of turbulent flow over a wall-mounted hump with active flow control are performedand comparedwithprevious experiments. Theflow is characterizedby the unsteady separationbefore the steep trailing edge, which naturally reattaches downstream of the hump to form an unsteady turbulent separation bubble. The lowMachnumber large-eddy simulation demonstrated a goodpr...

The growth and breakdown of localised disturbances into a turbulent spot in a Mach 2 boundary-layer flow have been investigated by direct numerical simulation. In particular, the interaction of a turbulent spot with a shock-induced separation bubble is studied. The primary vortex structures triggered by the injected low momentum fluid and the metamorphosis of the hairpin structures into a turbu...

When an impurity is doped in a solid, it inevitably induces a local stress, tending to expand or contract the lattice. Consequently, strain can be applied to change the solubility of impurity in a solid. Generally, the solubility responds to strain "monotonically," increasing (decreasing) with the tensile (compressive) strain if the impurity induces a compressive stress or vice versa. Using fir...

We report on a lithographic mode of electrochemically triggered free radical polymerization. The polymerization is initiated by the reduction of an electrochemically active initiator. Hydrogel patterns can be written by employing a small insulated counter electrode. The investigations show that the "pen" actually is a small oxygen bubble between the counter electrode and the sample surface. The...

The collimation of an isotropic, non-magnetic protostellar wind by an ordered magnetic eld in the ambient medium is investigated using self-consistent magnetohydrodynamic simulations in two-dimensions. The strong protostellar wind in ates a low density bubble in the ambient medium. The growth of this bubble is con ned along the direction of the ambient magnetic eld when the gas pressure in the ...

Simulated mixing rates of the Rayleigh-Taylor instability for miscible fluids with physical mass diffusion are shown to agree with experiment; for immiscible fluids with physical values of surface tension the numerical data lie in the center of the range of experimental values. The simulations are based on an improved front tracking algorithm to control numerical surface tension and on improved...

An analytical model of the nonlinear bubble evolution of single-mode, classical Rayleigh-Taylor instability at arbitrary Atwood numbers (A(T)) is presented. The model is based on an extension of Layzer's theory [Astrophys. J. 122, 1 (1955)] previously applied only to the fluid-vacuum interfaces (A(T) = 1). The model provides a continuous bubble evolution from the earlier exponential growth to t...

We present results from direct, large-scale molecular dynamics simulations of homogeneous bubble (liquid-to-vapor) nucleation. The simulations contain half a billion Lennard-Jones atoms and cover up to 56 million time steps. The unprecedented size of the simulated volumes allows us to resolve the nucleation and growth of many bubbles per run in simple direct micro-canonical simulations while th...

Experiments were performed to study subcooled film boiling of performance liquid PF5060 (made by 3-M Company) on a horizontal copper disc. The experiments were performed for two regimes of film boiling involving departing vapor bubbles (low subcooling) and nondeparting vapor bubbles (high subcooling). By employing high speed digital camera, data were obtained for temporal variation of bubble he...