Stellar Yields of Rotating First Stars: Yields of Weak Supernovae and Abundances of Carbon-enhanced Hyper Metal Poor Stars

The three most iron-poor stars known until now are also known to have peculiar enhancements of intermediate mass elements. Under the assumption that these iron-deficient stars reveal the nucleosynthesis result of Pop III stars, we show that a weak supernova model successfully reproduces the observed abundance patterns. Moreover, we show that the initial parameters of the progenitor, such as the initial masses and the rotational property, can be constrained by the model, since the stellar yields result from the nucleosynthesis in the outer region of the star, which is significantly affected by the initial parameters. The initial parameter of Pop III stars is of prime importance for the theoretical study of the early universe. Future observation will increase the number of such carbon enhanced iron-deficient stars, and the same analysis on the stars may give valuable information for the Pop III stars that existed in our universe.

Component Modeling of Steel Bolted End-Plate Joints under Bending and Shearing Loads

Based on the component method of EuroCode3, a new component model to evaluate rotational properties of extended end-plate beam-to-column joints under shearing and bending loads has been proposed in this paper. Firstly, the T-stub model was set up. And then the end-plate beam-to-column joint was simplified with a set of T-stubs. Finally the end-plate beam-to-column joint was simulated by the proposed component model consists of a series of levers and equivalent springs. With the purpose of verifying and calibrating the proposed model, an experiment of extended end-plate joint is recommended and a corresponding finite element model has also been set up. Results of experiment, FEM and component model fit well each other. The method of this paper can describe the rotational property of end-plate joint under beading moment and shear with enough precision, which can be a useful improvement to conventional design codes.