One of the simplest pseudo-Hermitian models with real spectrum (viz., square-well on a real interval I of coordinates) is re-examined. A PT −symmetric complex deformation C of I is introduced and shown tractable via an innovated approach to matching conditions. The result is surprising: an arbitrarily small deformation I → C implies a sudden collapse (i.e., the spontaneous PT −symmetry breaking...

[1] Fogo volcano, Cape Verde Islands, erupted in April 1995 after 43 years of dormancy. About 46 10 m of lava erupted during 7.5 weeks from vents on the SW flank of Pico do Fogo into Cha das Caldeiras. Interferograms obtained from 1993–1998 ERS SAR data show ground deformation due to the feeder dike but lack evidence for any volcano-wide deformation related to volume changes of a shallow magma ...

This paper is concerned with the airway closure problem and investigates the quasi-steady deformation characteristics of strongly collapsed (buckled) airways occluded by liquid bridges of high surface tension. The airway wall is modeled as a thin-walled elastic shell, which deforms in response to an external pressure and to the compression due to the surface tension of the liquid bridge. The go...

We use different determinantal Hartree–Fock (HF) wave functions to calculate true variational upper bounds for the ground state energy of N spin-half fermions in volume V0, with massm, electric charge zero, and magnetic moment μ, interacting through magnetic dipole–dipole interaction. We find that at high densities when the average interparticle distance r0 becomes small compared to the magneti...

Retamal Montes, J. 2016. Aspects on ventilation induced stress and strain on regional and global inflammation in experimental acute respiratory distress syndrome. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine 1235. 64 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-554-9612-8. Mechanical ventilation (MV) is a life-saving therapy in acute respirat...

The Interferometric Point Target Analysis (IPTA) technique and Advanced Synthetic Aperture Radar (ASAR) images acquired over Hong Kong from 2007-2008 were used to detect ground deformation in the urban area of Guangzhou city in South China. A ground deformation rate map with scattered distribution of point targets shows the maximum subsidence (rise) rate as high as -26 to -20 mma(-1) (16-21 mma...

Application of impact energy absorption systems in different industries is of special significance. Thin-walled tubes, due to their lightness, high energy absorption capacity, long crushing length and the high ratio of energy absorption to weight, have found ever-increasing application as one of the most effective energy absorption systems. In this research, through  carrying out experimental t...

We probe the local mechanical properties of microtubules at the nanometer scale by radial indentation with a scanning force microscope tip. We find a linear elastic regime that can be described by both thin-shell theory and finite element methods, in which microtubules are modeled as hollow tubes. We also find a nonlinear regime and catastrophic collapse of the microtubules under large loads. T...

A free-Lagrange numerical method is implemented to simulate the axisymmetric jetting collapse of air bubbles in water. This is performed for both lithotripter shock-induced collapses of initially stable bubbles, and for free-running cases where the bubble initially contains an overpressure. The code is validated using two test problems (shock-induced bubble collapse using a step shock, and shoc...