two us planes
61USS Van Valkenburgh (DD-656) — was a sclass|Fletcher|destroyer of the United States Navy, named for Captain Franklin van Valkenburgh (1888–1941), captain of the battleship USS|Arizona|BB 39|2 when the Japanese attacked Pearl Harbor. Van Valkenburgh was laid down on 15 November …
62USS Porterfield (DD-682) — was a Fletcher class destroyer of the United States Navy, named for Rear Admiral Lewis B. Porterfield (1879–1942). Porterfield was laid down by the Bethlehem Steel Co., San Pedro, California 12 December 1942; launched 13 June 1943; sponsored by… …
63International Touring Competition 1930 — The International Touring Competition in 1930 (French: Challenge International de Tourisme) was the second FAI international touring aircraft contest, that took place between July 18 and August 8, 1930 in Berlin, Germany. Four Challenges, from… …
64Rotation (mathematics) — Rotation of an object in two dimensions around a point O. In geometry and linear algebra, a rotation is a transformation in a plane or in space that describes the motion of a rigid body around a fixed point. A rotation is different from a… …
65Canal inclined plane — An inclined plane is a system used on some canals for raising boats between different water levels. Typically, such a feature consists of a slope, up which there are two sets of rail tracks. Boats are raised between different levels by sailing… …
66Rendition aircraft — Illegal rendition flights of the CIA, as reported by Rzeczpospolita [1] Rendition aircraft are aircraft used by national governments to move prisoners internationally, a practice known as rendition, sometimes referred to as extraordinary… …
67Ray transfer matrix analysis — (also known as ABCD matrix analysis) is a type of ray tracing technique used in the design of some optical systems, particularly lasers. It involves the construction of a ray transfer matrix which describes the optical system; tracing of a light… …
682007 Greek forest fires — Infobox wildfire title = 2007 Greek forest fires caption = Animation showing fires in southern Greece (22 26 August 2007), from NASA satellite images. location = Greece: Peloponnese, Attica and Euboea date = June 28 2007 September 3 2007 time =… …
69Rotation matrix — In linear algebra, a rotation matrix is a matrix that is used to perform a rotation in Euclidean space. For example the matrix rotates points in the xy Cartesian plane counterclockwise through an angle θ about the origin of the Cartesian… …
70Orthotropic material — Wood is an example of an orthotropic material. Material properties in three perpendicular directions (axial, radial, and circumferential) are different. An orthotropic material has two or three mutually orthogonal twofold axes of rotational… …
