The dynamical response of magnetic flux tubes due to local transverse periodic perturbations is investigated by numericalmeans.Our aimwas to check the applicability of the thin flux tube approximation for vertically oriented flux tubes with moderate magnetic field strength (plasma β = 1) and diameters 100 km, 50 km and 25 km immersed in an otherwise homogeneous nonmagnetic environment. All tube...

Dirichlet Laplacian on curved tubes of a constant cross section in two and three dimensions is investigated. It is shown that if the tube is non{straight and its curvature vanishes asymptotically, there is always a bound state below the bottom of the essential spectrum. An upper bound to the number of these bound states in thin tubes is derived. Furthermore, if the tube is only slightly bent, t...

A set of dynamical equations are derived for a slender tube of isolated magnetic ux generalizing a model due to Spruit. The tube is assumed to consist of eld lines which twist about the tube's axis at some rate q. The equations describe the evolution of the axis and the evolution of the twist. They include the interaction between twist and motions of the axis described as writhing. Through this...

A new ultrasonic suction pump is described in this paper. The pump uses suction force of the rigid cylinder tube vibrating at an ultrasonic frequency and has no physically moving parts. The pump is consists of a longitudinal bolt-clamped Langevin transducer (BLT) combined with a stepped horn working at its resonance frequency of 24 kHz. A glass tube of the half-wavelength-resonance length is gl...

We investigate the net effect of a multitude of thin magnetic tubes on the energy of ambient acoustic p modes. A p mode, when incident on a thin magnetic flux tube, excites magnetohydrodynamic (MHD) tube waves. These tube waves propagate vertically along the flux tube carrying away energy from the p-mode cavity resulting in the absorption of incident p-mode energy. We calculate the absorption a...

assessing the behavior of composite structures which are subjected to impact loads is one of the important subjects in the field of mechanical sciences. using thin-walled tubes which collapsed and absorbed the impact energy is a well-known method to prevent damages to the other parts of the structures. in this paper, deformations, crushing length, peak load, mean force and energy absorption cap...