Polyethylene pipes are widely used in water supply, gas, and sewage systems due to their excellent mechanical properties. A slow crack growth is the primary fracture mechanism for the pipes under long-term internal pressures. ...

Suppose that G is a finite group and H is a subgroup of G. H is called ss-quasinormal in G if there is a subgroup B of G such that G=HB and H permutes with every Sylow subgroup of B; H is called weakly s-supplemented in G ...

With consideration of the intermediate principal stress and different strength values in tension and compression, the plastic analysis of metallic elbows under internal pressure is conducted based on the unified strength ...