Abstract Structures made of hollow sections are often used in the construction steel bridges, agricultural machinery and trucks. Due to secondary bending moments local stress concentrations at connection between brace chord these joints have a low fatigue strength. In case high‐strength steels, decisive design leads larger wall thicknesses dimensions thus uneconomical constructions. course rese...

The Continuous Strength Method (CSM) is a deformation based design approach that provides accurate cross-section resistance predictions by making rational allowance for the interaction between elements, partial spread of plasticity and beneficial effects strain hardening. CSM can be used in conjunction with advanced analysis members frames, but, hand calculations, member-level stability checks ...

Ceramic hollow spheres of MoS2 and MoO3 were obtained by sonochemical synthesis of MoS2 and MoO3 templated on silica nanoparticles (diameters 50-500 nm) followed by acid etching to remove the silica core. The resulting hollow materials have been characterized by elemental analysis, XPS, SEM, TEM, optical absorption, and hydrodesulfurization (HDS) studies. The TEM studies on the hollow ceramic m...

Double-shell cobalt monoxide (CoO) hollow particles were successfully synthesized by a facile and effective one-pot solution-based synthetic route. The inner architecture and outer structure of the double-shell CoO hollow particles could be readily created through controlling experimental parameters. A possible formation mechanism was proposed based on the experimental results. The current synt...

We report herein a facile method for the preparation of sodium tungsten bronzes hollow nanospheres using hydrogen gas bubbles as reactant for chemical reduction of tungstate to tungsten and as template for the formation of hollow nanospheres at the same time. The chemical composition and the crystalline state of the as-prepared hollow Na0.15WO3nanospheres were characterized complementarily, and...

Internal decays in trees can rapidly escalate into a full decomposition of the inner structural layer, i.e., “heartwood” due to action aggressive diseases and fungal infections. This process leads formation big cavities hollows, which remain surrounded by sapwood layer only. Estimating thickness with high degree accuracy is therefore crucial for correct assessment integrity hollow trees, as wel...

membrane technology is used to separate water or solvents from salts or pollutants. this technique could be used for water treatment. for using of polyether sulfone (pes) hollow fiber membranes in water treatment processes, the pes hollow fiber membranes were prepared by dry-wet spinning method and heated in an oven at: 120°c, 150°c and 180°c. the effect of heating on performance of membranes w...

NiS2 hollow spheres are successfully prepared by a one-step template free method. Meanwhile, α-NiS hollow spheres can also be synthesized via the calcination of the pre-obtained NiS2 hollow spheres at 400 °C for 1 h in air. The electrochemical performances of the as-prepared NiS2 and α-NiS hollow sphere products are evaluated. When used for supercapacitors, compared with NiS2 hollow spheres, th...

ZnO-SnO2 hollow spheres were successfully synthesized through a hydrothermal method-combined carbon sphere template. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR). The average diameter of hollow spheres is about 150 nm. The photocatalytic activity of the a...

In this study, a topotactic transformation route was proposed to synthesize single-crystalline β-NiS hollow spheres with uniform phase and morphology evolving from polycrystalline α-NiS hollow spheres. Uniform polycrystalline α-NiS hollow spheres were firstly prepared with thiourea and glutathione as sulfur sources under hydrothermal conditions through the Kirkendall effect. By increasing the r...