| reversed-three sign | On an oesophagram of a patient with coarctation of the aorta, the shape of the contrast-filled oesophagus caused by the aortic arch (upper convexity) and post-stenotic dilatation (lower convexity); the cusp of the backwards 3 is at the level of the coarctation itself. (05 Mar 2000) |
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| field-reversed configuration | <radiobiology> A compact torus produced in a theta pinch and having (in principle) no toroidal field. The potential advantages for a fusion reactor include a simple (linear) machine geometry, an average plasma pressure close to the confining field pressure, and physical separation of formation and burn chambers. The are predicted to be violently unstable to tilting, but this is rarely observed. (09 Oct 1997) |