A rectangular drawing of a plane graph G is a drawing of G such that each vertex is drawn as a point, each edge is drawn as a horizontal or a vertical line segment, and the contour of each face is drawn as a rectangle. A necessary and sufficient condition for the existence of a rectangular drawing has been known only for the case where exactly four vertices of degree 2 are designated as corners...

The previously unknown crystal structure of barium perchlorate anhydrate, determined and refined from laboratory X-ray powder diffraction data, represents a new structure type. The title compound was obtained by heating hydrated barium perchlorate [Ba(ClO4)2·xH2O] at 423 K in vacuo for 6 h. It crystallizes in the ortho-rhom-bic space group Fddd. The asymmetric unit contains one Ba (site symmetr...

The role of environmental geometry in maintaining spatial orientation was measured in immersive virtual reality using a spatial updating task (requiring maintenance of orientation during locomotion) within rooms varying in rotational symmetry (the number of room orientations providing the same perspective). Spatial updating was equally good in trapezoidal, rectangular and square rooms (one-fold...

As an analytical type of approach, Critical Discourse Analysis (CDA) deals with the emphasis on social practice, identity, power, and ideology built through text and speech in socio-political and educational contexts. Having proposed a theoretical framework, it uncovered all discrepant ways through which power and societal practices are produced in written and spoken texts. Moreover, mingled wi...