A vector Sd-flow is a flow whose flow values are vectors in Sd, where Sd is the set of all unit vectors in Rd+1. Jain [Open Problem Garden, http://www.openproblemgarden.org/op/unit vector flows (2007)] and Thomassen [J. Combin. Theory Ser. B., 108 (2014), pp. 81–91] proved that a graph has a vector S1-flow if it has a nowhere-zero integer 3-flow. Thomassen [J. Combin. Theory Ser. B., 108 (2014)...

Despite the great potential of graphene as a nanofiller, achieving homogeneous dispersion remains the key challenge for effectively reinforcing polyolefin (such as polyethylene (PE) and polypropylene (PP)) nanocomposites. Therefore, in this research, we report a facile combined in situ polymerization and masterbatch method for fabricating PP/reduced graphene oxide (rGO) nanocomposites. In the p...

A fourth-generation Ziegler-Natta catalyst was prepared to synthesize polypropylene (PP), which was stabilized by in situpolymerization employing lignin as antioxidant. The antioxidant properties of lignin were compared with those of the commercial antioxidant Irganox 1010. The presence of lignin in the reaction medium slightly decreased the catalytic activity of the reaction. The isotacticity ...

Min introduces the type form (of object-formulae) and the infix constant −→ (for objectimplication). The constant [[ ]] maps form to the predefined type prop of meta-logic propositions. The proposition [[P ]] should be read as “the formula P is true”; we usually distinguish object-level formulae (form) from meta-level formulae (prop). In practice the brackets can be dropped; parser and pretty-p...