Interferometric synthetic aperture radar (InSAR) was used to measure ground deformation during explosive eruptions on 27 and 28 May 2010 at Pacaya volcano, Guatemala. Interferograms produced using spaceborne and airborne synthetic aperture radar data reveal ~3 m of along-slope movement of the southwest sector of the edifice during these eruptions. This is the largest measured slope instability ...

Upon an increase of moisture, unsaturated soil may collapse or swell, depending on the loading state and history. This important characteristic must be realistically reproduced by a constitutive model aimed for practical applications. In addition to collapse/swelling, other essential features, such as deformation and failure following arbitrary shearing paths, must also be realistically reprodu...

An analytic estimation of the mass function for gravitationally bound objects is presented. We use the Zel’dovich approximation to extend the Press-Schecter analysis to nonspherical collapse. For the Zel’dovich approximation, the gravitational collapse along all three directions which will eventually lead to the formation of real virialized objects clumps occurs in the regions where the lowest ...

The spatial fluctuations of deformation are studied in the creep in Andrade's power law and the logarithmic phases, using paper samples. Measurements by the digital image correlation technique show that the relative strength of the strain rate fluctuations increases with time, in both creep regimes. In the Andrade creep phase characterized by a power-law decay of the strain rate ϵt∼t(-θ), with ...

Global Positioning System geodesy was used to measure surface deformation on Soufriere Hills volcano, Montserrat from October 6, 1995 to July 1, 1997 during initial dome growth and gravitational collapse. Our data from this period show non-axially symmetric horizontal displacements, and decreasing subsidence as a function of radial distance from the former topographic high of the volcanic edifi...

The dynamics of cavitation bubbles and their interaction with solids has been studied for long, mostly on the macro-scale sheet vortex cavitation. Erosion takes place small, concentrated areas solid walls exposed to One-way fluid structure (FSI), in which feedback material deformation is not considered, provides an adequate understanding underlying mechanism. However, practical applications mot...

In this paper, the physical behaviors of the interaction between a spark-generated bubble and a rubber beam are studied. Both numerical and experimental approaches are employed to investigate the bubble collapse near the rubber beam (which acts as a flexible boundary) and the corresponding large deformation of the beam. Good agreement between the numerical simulations and experimental observati...

BACKGROUND Tracheal obstruction resulting from expiratory tracheal deformation has been associated with respiratory symptoms and severe airway exacerbations. In chronic obstructive pulmonary disease (COPD), acute exacerbations (AECOPD) create large intrathoracic pressure swings which may increase tracheal deformation. Excessive central airway collapse (ECAC) may be diagnosed when the tracheal a...

Recent X-ray diffraction, NMR spectroscopy and molecular mechanics results suggest that monovalent cations selectively partition into the minor groove of AT-tracts in DNA. These observations are consistent with DNA deformation by electrostatic collapse around areas of uneven cation density. This model predicts the occurrence of known DNA deformations, such as AT-tract bending and changes in the...