Helix angle the helix angle. The efficiency can be plotted versus the helix angle for a constant friction, as shown in the adjacent diagram. The maximum efficiency is a helix angle between 40 and 45 degrees, however a reasonable efficiency is achieved above 15°. Due to difficulties in forming the thread, helix angle greater than 30° are rarely used. Moreover, above 30° the friction angle becomes smaller than the helix angle and the nut is no longer self-locking and the mechanical advantage disappears. In helical and worm gears, the helix angle denotes the standard pitch circle unless otherwise specified. Application of the
Less than Angels with an air of detachment. Anne Wyatt-Brown writes that "Catherine represents Pym’s view of the world. She shares her author’s imagination, her amused reaction to anthropologists, and her detachment." Less than Angels Less Than Angels is a novel by Barbara Pym, first published in 1955. The novel is largely concerned with the activities of a group of anthropologists, and is to some extent based on the author's own experiences working at the International African Institute in London. It is set in a period of social change which is subtly represented within the novel's plot and setting Catherine Oliphant is a