Study of a new type of crimped-shape nanotubes cut from bilayer graphene with the Moiré angle $\Theta=27.8^\circ$

New quasi-one-dimensional hollow nanostructures similar to flattened nanotubes are numerically simulated. These nanostructures can be obtained by connecting the edges of nanoribbons cut out of twisted bilayer graphene with the Moiré angle $\Theta=27.8^\circ$. The resulting nanotubes are non-chiral and contain chains of topological defects at the connected edges. A detailed description of their structure is given, and their energy stability is also demonstrated. The electronic characteristics of such structures and their evolution in the course of deformation are determined using ab initio methods. All nanotubes under study are metallic, except the structure with a width of $14$ Å, characterized by the band gap $E_g = 0.2$ eV. It is shown that the electronic and elastic characteristics of such nanotubes differ significantly from those of nanoribbons forming them and of single-walled carbon nanotubes.