Abstract: The invention relates to a turbine comprising a primary rotor, for positioning in a fluid flow, having a primary rotor blade rotatable around a primary rotor axis under influence of the fluid flow acting on the primary rotor blade and extending from the primary rotor axis along a longitudinal axis to a free outer end of the primary rotor blade. The primary rotor blade is provided near the free outer end with a secondary rotor. The secondary rotor has a secondary rotor blade rotatable around a secondary rotor axis in response to a rotation of the primary rotor blade around the primary rotor axis. The secondary rotor axis is substantially transverse to the longitudinal axis of the primary rotor blade. The secondary rotor axis is also substantially transverse to the primary rotor axis. The turbine is characterised in that the secondary rotor axis is positioned offset from the longitudinal axis of the primary rotor blade.

Abstract: An apparatus for creating or modifying browser-renderable teaching objects for use in creating a browser-renderable textbook data object. The apparatus includes a database, a network interface for receiving a source file containing codes for creating or modifying the browser-renderable teaching objects by way of a network, and a processor configured to create or modify the teaching objects based on the codes, and store the teaching objects in the database. A first code instructs the processor to create at least one browser-renderable section object for the textbook data object, the first code including a first attribute configured to instruct the processor to configure the at least one section object such that, when rendered by a browser module, a specified section title is provided at a beginning of the at least one section object; and (2) set of codes configured to instruct the processor to create or modify the teaching objects within the at least one section object.