This weekly report details technical activities for the week ending May 15, 1943.

The following memorandum discusses experiments and methods to recover uranium from Colorado-Utah sandstone and leaving the vanadium in the tails, improving filterability.

"In this report are presented three figures which show how the relative activities (expressed as percentages of total activity) of the individual fission elements (produced by neutron bombardment of uranyl nitrate) vary with cooling time."

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Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Gerald Mann, regarding a legal question submitted for clarification: Whether Texas assessed against the interest of a former purchaser of State School Lands constitute a lien against such property in the hands of a new purchaser under a subsequent sale, and related question.

The two-dimensional, incompressible potential flow past a lattice of airfoils of arbitrary shape is investigated theoretically. The problem is treated by usual methods of conformal mapping in several stages, one stage corresponding to the mapping of the framework of the arbitrary line lattice and another significant stage corresponding to the Theodorsen method for the mapping of the arbitrary single wing profile into a circle. A particular feature in the theoretical treatment is the special handling of the regions at an infinite distance in front of and behind the lattice. Expressions are given for evaluation of the velocity and pressure distribution at the airfoil boundary. An illustrative numerical example is included.

"An analysis is made of the stability of an airplane with ailerons free, with particular attention to the motions when the ailerons have a tendency to float against the wind. The present analysis supersedes the aileron investigation contained in NACA Technical Report no. 709. The equations of motion are first written to include yawing and sideslipping, and it is demonstrated that the principal effects of freeing the ailerons can be determined without regard to these motions" (p. 255).

Report presenting stability, maximum lift, and high-speed tests of an observation airplane fitted with Maxwell leading-edge slots. The static and dynamic longitudinal and lateral stability was generally satisfactory and not affected much by the slots.

Discusses the purpose and usage of the pneumatic pontoon bridge M3 by infantry in the field. Covers construction, deployment, and maintenance.

A manual describing the use of sled dogs as a means of military transportation in Arctic regions.

Front: Text describes action on various war fronts: Sicily, Air offensive, Russia, New Georgia, New Guinea, Aleutians, Submarines. Includes list of senior commanders in the Invasion of Italy. Maps: New Georgia Islands; American 7th army positions in Licata and Vittoria Italy. Inset map: Italy and surrounding islands. Illustration: Landing on the underside [Allied air attack on ships unloading military cargo on the beaches of Southern Sicily]. Back: Text and color illustrations include various methods of enemy gas applications.

Front: Text describes action on various war fronts: Tunisia -- Southwest Pacific -- Russia -- Mediterranean. Large world map is keyed to text and illustrates time zones around the world. Inset maps show Allied drive in Tunisia -- Japanese controlled areas throughout the Southwest Pacific. Includes photographs: Helping Rommel's run [puppy stationed atop a Vickers machine gun] -- So he can fight (Staff Sergt. Hollers clerks at the San Angelo AAF Bombardier School in Texas) -- Blimp training. Back: Tunisia, map with inset showing location of Tunisia in the Mediterranean area.