We consider a beam whose cross-section is a tubular neighborhood of a simple closed curve γ. We assume that the wall thickness, i.e., the size of the neighborhood, scales with a parameter δε while the length of γ scales with ε. We characterize a thin-walled beam by assuming that δε goes to zero faster than ε. Starting from the three dimensional linear theory of elasticity, by letting ε go to ze...

Anisotropic optical absorption properties of single-walled carbon nanotubes (SWNTs) are determined from a vertically aligned SWNT film for 0.5-6 eV. Absorption peaks at 4.5 and 5.25 eV are found to exhibit remarkable polarization dependence and have relevance to optical properties of graphite. A method for determining a nematic order parameter for an aligned SWNT film based on the collinear abs...

Two new Penicillium species isolated from plant leaves are reported here, namely, P. fusisporum (type strain AS3.15338T = NRRL 62805T = CBS 137463T) and P. zhuangii (type strain AS3.15341T = NRRL 62806T = CBS 137464T). P. fusisporum is characterized by fast growth rate, apical-swelling monoverticillate penicilli, verrucose stipes, fusiform to oblong conidia about 3.5-4×2-2.5 µm and cinnamon-col...

HIstology: Section from the lesion shows a large focus of caseous necrosis rimmed by epithelioid cells, lymphocytes, macrophages and Langhan’s giant cells and a dense collagenous wall. Within the caseous necrosis, ghost outlines of necrosed blood vessels are seen surrounded by an eosinophilic, fibrinous material which represents tuberculous immune complex deposition. A thin compressed collar of...

-The characteristics of a number of metal components proposed as impact energy absorbers are reviewed, attention being focussed on to modes of deformation which stem from the axial compression of metal tubes. Progressive buckling, inversion and splitting are discussed and areas for future work identified. The buckling of thin-walled square section tubes filled with polyurethane foam is also des...

This paper presents the results of finite-element simulations leading to development a design method using direct strength (DSM) for transversely loaded thin-walled steel beams prone local and distortional buckling failures at elevated temperatures. The systematic extensive numerical parametric study covers different dimensions sections, temperature distributions in cross-section, grades load r...

The elastic buckling modes of pultruded I-beams subjected to various loading conditions are studied. The coupling of lateral and distortional buckling, very likely to appear in thin-walled cross-sections, is investigated. Plate theory is used to allow for distortion of the cross-section. Shear effects and bendingt\\isting coupling are accounted for in the analysis, because of their significant ...

Relatively low magnetic fields applied parallel to the axis of a chiral single-walled carbon nanotube are found causing large modulations to the p channel or valence band conductance of the nanotube in the Fabry-Perot interference regime. Beating in the Aharonov-Bohm type of interference between two field-induced nondegenerate subbands of spiraling electrons is responsible for the observed modu...

In this paper the optimal model of thin-walled sections of automotive body for structural crashworthiness is built. With computer design of experiment (DOE), the response surface model (RSM) of design can be obtained by carefully choosing a small quantity of samples in the design space. Pareto genetic algorithm (GA) is used in subsequently optimal design. With optimal design of thin-walled sect...

Material properties and geometry are two important design parameters which their effects should be considered in a crashworthiness analysis. In this paper, the axial impact of metallic and hybrid energy absorbing thin-walled tubes with poly-gonal cross-section is simulated using LS-DYNA software. The combined effects of changing the geometry and material properties on the mass specific energ...