we studied litterfall dynamic of tree plantations in dez river floodplain, at 14 to 15 years old. the plantations consist of populus euphratica oliv., eucalyptus camaldulensis dehnh., e. microtheca f. muell, acacia farnesiana (l.) willd., a. salicina lindl., a. saligna (labill.) h. wendl., a. stenophylla benth. and dalbergia sissoo roxb. litterfall was different between the tree species, and le...

The present research is concerned with the determination of ductility, over-strength and response modification factors of coupled steel shear wall frames. Three structural models with various numbers of stories, bay width and coupling beam height were analyzed using static pushover and incremental nonlinear dynamic analyses. The ductility, over-strength and response modification factors for the...

the problem of several finite moving cracks in a functionally graded material is solved by dislocation technique under the condition of anti-plane deformation. by using the fourier transform the stress fields are obtained for a functionallygraded strip containing a screw dislocation. the stress components reveal the familiar cauchy singularity at thelocation of dislocation. the solution is empl...

The determination of structural and nonstructural damage under earthquake excitations is usually considered as a key factor in performance-based seismic design (PBSD) methods is In this regard, various damage indices have been developed in recent years to quantitatively estimate structural damage. The aim of this study is to develop a simple method to evaluate performance levels of zipper-brace...