Report presenting an investigation of the ditching characteristics of the Boeing 707 jet transport in tank no. 2. Various conditions of damage, landing attitude, and speed were investigated. Data were obtained from visual observations, acceleration records, and motion pictures.

"Large downstream movements of transition observed when the leading edge of a hollow cylinder or a flat plate is slightly blunted are explained in terms of the reduction in Reynolds number at the outer edge of the boundary layer due to the detached shock wave. The magnitude of this reduction is computed for cones and wedges for Mach numbers to 20. Concurrent changes in outer-edge Mach number and temperature occur in the direction that would increase the stability of the laminar boundary layer. The hypothesis is made that transition Reynolds number is substantially unchanged when a sharp leading edge or tip is blunted" (p. 709).

The possible hazards from the refining and processing of thorium are of wide interest in atomic energy work. A review of the data available was made at Hanford in the last year to support consultations on the hazards of radioisotopes with other plants which may handle thorium. Since a major discrepancy between the published values of air MPC's and the metabolic data was noted, a review of the calculations on thorium was made in order to obtain the best estimates available. This document tabulates the pertinent data and applies them to the calculation of the MPC of thorium.