Quasi-static shear crack propagation in a linear elastic fluid-saturated porous solid c;Iuses a change of pore pressure on the crack plane if it is impermeable but not if it is permeable. Assuming that the pore pressure induced on the crack plane reduces the efTcclive compressive stress (total stress minus pore fluid pressure) and. as a result. the frictional resistance. we find that the energy...

Vibration energies generated by laser irradiation to a plate with a crack were calculated by the semi-analytical finite element method to elucidate the principle of defect imaging using a scanning laser source. For normal incidence in the ablation regime, the incident energy increases when the incident source is located in the vicinity of the crack, owing to the effect of the non-propagating A1...

People who smoke crack cocaine are described as chaotic and more likely to engage in risky sex, polysubstance use and contract infectious diseases. However, little is known about how individuals perceive smoking crack as compared to other forms of cocaine use, especially injection. We explored the lived experience of people who smoke crack cocaine. Six gender-specific focus groups (n = 31) of i...

This study characterizes the family ties of crack cocaine users cared for in a psychiatric emergency department in southern Brazil. It is a qualitative study with a series of cases carried out in the city of Maringá, PR, Brazil from April to June 2010. Data were collected through semi-structured interviews, analyzed using content analysis, and organized into two categories: family ties as facil...

Dynamic analysis of two collinear electro-magnetically dielectric cracks in a piezoelectromagnetic material is made under in-plane magneto-electro-mechanical impacts. Generalized semi-permeable crackface boundary conditions are proposed to simulate realistic opening cracks with dielectric. Ideal boundary conditions of a combination of electrically permeable or impermeable and magnetically perme...

In this paper a new approach is taken to identify a crack in a simply supported plate undergoing free vibration. The approach uses a Markov-Chain MonteCarlo implementation of Bayes’ Rule to identify the presence of a crack and, more importantly, to estimate crack parameters; the process also provides confidence intervals for those parameters. To generate the required time series, a semi-analyti...

Abstract To effectively reduce the field concentration around a hole or crack, an anti-plane shear problem of nano-elliptical nano-crack pasting reinforcement layer in one-dimensional (1D) hexagonal piezoelectric quasicrystal (PQC) is investigated subject to remotely mechanical and electrical loadings. The surface effect dielectric characteristics inside are considered for actuality. By utilizi...