PURPOSE In ultrasound-guided High Intensity Focused Ultrasound (HIFU) therapy, the target tissue (such as a tumor) often moves and/or deforms in response to an external force. This problem creates difficulties in treating patients and can lead to the destruction of normal tissue. In order to solve this problem, we present a novel method to model and predict the movement and deformation of the t...

We give some results about the dynamics of a particle moving in Euclidean three-space under the influence of the gravitational force induced by a fixed homogeneous circle. Our main results concern (1) singularities and (2) the dynamics in the plane that contains the circle. The study presented here is purely analytic. In this paper we present a first study about the movement of a particle in Eu...

Wind-blown sand movement often occurs in a very complicated desert environment where sand dunes and ripples are the basic forms. However, most current studies on the theoretic and numerical models of wind-blown sand movement only consider ideal conditions such as steady wind velocity, flat sand surface, etc. In fact, the windward slope gradient plays a great role in the lift-off and sand partic...

Water injection is used as a widespread IOR/EOR method and promising formation damages (especially mechanical ones) is a crucial challenge in the near-wellbore of injection wells. The magnesium oxide (MgO) NanoParticles (NPs) considered in the article underwater flooding experiment tests to monitor the promising mechanical formation damage (size exclusion) in lab mechanistic scale include m...

This paper establishes a granular mechanics model for the stable movement of material particle group in vertical screw unloader with mechanics, continuum and theory innovatively proposed hypothesis that speed changes radially spiral groove. Through analysis movement, characteristic parameters are determined. The study found free surface type longitudinal section conveyor its identification solu...

During the various technological operations in fields of industry and production, working bodies machines tools interact with particles material. At same time, geometric shape surface determines character movement on it. Particles material are often considered as particles, which is acceptable because their small dimensions. In this case, inertial forces from rotation not taken into account, a ...