We propose a new class of approximate local DtN boundary conditions to be applied on elliptical-shaped exterior boundaries when solving acoustic scattering problems by elongated obstacles. These conditions are : (a) exact for the first modes, (b) easy to implement and to parallelize, (c) compatible with the local structure of the computational finite element scheme, and (d) applicable to exteri...

Geometric imperfections such as radial imperfection, diamond shape, and local dimples could affect the buckling mode and load carrying capacity of axially compressed steel tubular columns. This paper experimentally investigates the effect of radial imperfection on the load carrying capacity of tubular columns. Test samples include 100 specimens with different values for diameter, length, thickn...

this paper describes experimental and numerical investigations on two specimens of frames composed of steel reinforced concrete beam and angle-steel concrete column under horizontal low cyclic loading. based on the test results, the relationship curves of the horizontal load-displacement and the failure modes are acquired. meanwhile the hysteretic behaviors, skeleton curves, stiffness degradati...

We consider slender languages, that is, languages for which the number of words of the same length is bounded from above by a constant. We prove that the slenderness problem is decidable for context-free languages and that the maximal number of words of the same length in a given context-free language is computable. Some e ective representations of slender context-free languages, as well as oth...

The genus Haplophyllum, which belongs to the Rutaceae family, includes 18 species in Iran. In this study, after collecting plant material, botanical identification and suitable drying, the essential oils from aerial parts of Haplophyllum robustum Bge. were extracted by three different isolation techniques, conventional hydrodistillation (HD), microwave-assisted hydrodistillati...

In a recent paper we introduced Parikh slender languages as a generalization of slender languages defined and studied by AndraSiu, Dassow, Pgun and Salomaa. Results concerning Pa&h slender languages can be applied in ambiguity proofs of context-free languages. In this paper an algorithm is presented for deciding whether or not a given context-free language is Parikh slender.

Effects of age and stand density of mother tree on seed germination, seedling biomass allocation, and seedling growth of Pinus thunbergii were studied. The results showed that age of mother tree did not have significant influences on seed germination, but it was significant on seedling biomass allocation and growth. Seedlings from the minimum and maximum age of mother tree had higher leaf mass ...