Analysis of Dynamic Shear Strain Distributed in Three Dimensional Earthdam Models

Dynamic shear strain distribution have been evaluated and illustrated for three dimensional earthdam models. The analysis method applied here is a simplified finite element method, which has proved to give vibration modes of an earthdam to a satisfactory level of accuracy by involving a smaller number of degrees of freedom. Mass and stiffness matrices of a dam have been formulated for two types of the shear modulus distribution, one uniform and the other linearly increasing with depth below the crest. Both magnitude and location of the maximum shear strain have been discussed in relation to topography of dam sites

Ground Motion Characteristics of the San Francisco Bay Area Detected by Microtremor Measurements

Microtremor measurement was done mainly in the damaged areas in San Francisco and Oakland after the 1989 Loma Prieta earthquake. The observation areas were (1) the Marina District, (2) Cypress Street, (3) the Embarcadero, and (4) South of Market District. Predominant frequency (Fp) and amplification factor (Ap) obtained from a spectral ratio between horizontal and vertical components were evaluated for each observation cite. Difference in the degree of damage in the areas (1) and (4) was coincident with difference in Ap and Fp. Significant difference could not be found in Ap and Fp between the areas (2) and (3)

Tsunami generation by dynamic displacement of sea bed due to dip-slip faulting

In classical tsunami-generation techniques, one neglects the dynamic sea bed displacement resulting from fracturing of a seismic fault. The present study takes into account these dynamic effects. Earth's crust is assumed to be a Kelvin-Voigt material. The seismic source is assumed to be a dislocation in a viscoelastic medium. The fluid motion is described by the classical nonlinear shallow water equations (NSWE) with time-dependent bathymetry. The viscoelastodynamic equations are solved by a finite-element method and the NSWE by a finite-volume scheme. A comparison between static and dynamic tsunami-generation approaches is performed. The results of the numerical computations show differences between the two approaches and the dynamic effects could explain the complicated shapes of tsunami wave trains.Comment: 16 pages, 10 figures, Accepted to Mathematics and Computers in Simulation. Other author's papers can be downloaded at http://www.cmla.ens-cachan.fr/~dutyk

Immunohistochemical expression of SKALP/elafin in squamous cell carcinoma of the oesophagus.

In this study, the immunohistochemical expression of a new inducible elastase inhibitor, SKALP (skin-derived anti-leucoproteinase)/elafin, in the tissue of squamous cell carcinoma and uninvolved oesophageal mucosa was studied using a polyclonal rabbit anti-serum against SKALP/elafin. The results were compared with the immunohistochemical staining of proliferating cell nuclear antigen (PCNA) and the TUNEL assay in serial sections. In non-malignant oesophageal mucosa, the expression of SKALP/elafin was localized in the cells of the stratified zone overlying the PCNA-positive basal zone. In oesophageal cancer, the incidence of the expression was significantly related to the degree of the differentiation of the tumour. Characteristically, the expression was almost limited in tumour cell nests that had a clear squamous phenotype. In tumour cell nests, the expression of SKALP/elafin was localized in the cells overlying PCNA-expressing cells and no expression was found in the cells that expressed PCNA; DNA fragmentation was often observed in the same cell layers as those in which SKALP/elafin immunoreactivity was found. This enzyme inhibitor is speculated to be involved in the induction of the cell differentiation and apoptosis of human squamous cell carcinoma cells of the oesophagus