The following document focuses on the study of the absorption spectra of americium chloride. Large samples and a spectrograph of great dispersion were used.

Introduction: "This report is an extension of NAA-SR-Memo-178. The results show the number of control rods as a function of the amount of reactivity to be controlled. Numerical solutions are given for a typical example and are readily obtainable for other cases."

Leaching and filtration tests were conducted on dump samples and current residues from Afrikander Lease and Babrosco properties on the Witwatersrand, South Africa.

Abstract: "A quantitative method for the determination of individual rare earths in thorium down to a level of 0.05 ppm, is described. The procedure consists of a chromatographic cellulose-columns separation followed by a solution-type spectrographic determination. Values are given for the recovery of a number of rare earths using this combined procedure."

A method using photographic emulsions for the study of neutron distributions is described. The construction of a simple machine for producing experimental critical assemblies in which the method has been used is reported. Sources of error are discussed. Curves of the perturbations when small spheres of various materials are placed in the center of the assembly are shown.

From abstract: High velocity disturbances are observed to propagate along the walls of a high explosive operated shock tube in advance of the plane shock. Experiments are presented which determine the dependence of the geometry, energy, and velocity of the disturbance on such variables as the gas contained in the shock tube, the shock strength, and the roughness and composition of the supporting boundary. A model is constructed to explain the flow within the disturbance. Arguments are presented which show the disturbance to result from radiation originating in the luminous plane shock...The purpose of this paper is to present the results of initial investigations made in an effort to describe the phenomenon of strong shocks developed in a shock tube by the detonation of high explosive charge.

Simple expression are derived for the time dependence of slowing down of neutrons in a simple media. In Section I, a method suggested by age theory is used, while in section II, a two parameter scattering function is employed. Results are compared with exact calculations.