Abstract We study the magnon spectrum of stacked zig-zag chains point magnetic dipoles with an easy axis. The anisotropy due to dipolar interactions and two-point basis chain unit cell combine give rise topologically non-trivial bands in 2D lattices. Adjusting distance between two sublattice sites causes a band touching, which triggers exchange Chern numbers volume switching sign thermal conduc...

Quantum gravity has been so elusive because we have tried to approach it by two paths which can never meet: standard quantum field theory and general relativity. These contradict each other, not only in superdense regimes, but also in the vacuum, where the divergent zero-point energy would roll up space to a point. The solution is to build in a regular, but topologically nontrivial distribution...

replacement of a tractor is an influential factor affecting timely farm operation. the accurate prediction of repair and maintenance costs is essential to selection of a replacement model. this study used empirical data for 60 two-wheel drive (2wd) tractors from astan ghods-e razavi agroindustry. the types and numbers of tractors used were the massey ferguson 285 (17), fiat (10), john deere 314...

This study examines Thematic Development types based on the framework of Systemic Functional Linguistics that are used by tertiary students. It aims to find out how students produce effectively and efficiently their report texts. The data were all clauses taken from fifteen students’ text divided into three levels: high, middle, low achievement. findings showed there patterns in text, they Them...