In connection with the problem of eliminating contamination of the atmosphere by the exhaust from the 221 Building ventilation air stacks, sand filters were previously recommended. Construction of a sand filter in West Area is about completed and construction of a filter in East Area is well underway. This report summarizes the status, technical findings, and comments and suggestions since the writer`s last Interim Report, dated August 6, 1948, was issued.

This report compares the activity and disintegration energy of fission products from metal under two conditions of exposure: 200 Megawatt-days integrated exposure over a period of 180 days, and 400 Megawatt-days integrated exposure over a period of 360 days. (JL)

Report presenting a wind-tunnel investigation of a semispan model of a wing swept back 63 degrees with an aspect ratio of 3.5 and a taper ratio of 0.25. The tests were conducted to evaluate the effects of Reynolds and Mach number on the aerodynamic characteristics of the wing. Results regarding the characteristics of the wing with the elevon undeflected, effectiveness of the elevon, effects of roughness strips, and effect of model deflection under varying loads are provided.

Report presenting an investigation of the maximum hovering time, or the time that a helicopter can sustain itself without motion, for helicopters using a reciprocating engine, by ramjet engines at the tips of rotor blades, and by pulse-jet engines at the tips of rotor blades. Testing showed that the reciprocating engine permitted much longer hovering time than the jet-propulsion engines, but the jet-propulsion engines were much lighter and could lift greater disposable loads.

"A two-dimensional wedge diffuser, designed to be used with a ducted-airfoil ram jet, was tested on a rocket-powered test vehicle up to a Mach number of 1.45. Orifice plates and a choking section behind the diffuser exit simulated burning in a combustion chamber by providing the proper pressure drop. Results obtained from these tests showed there was no abrupt changes in mass flow and pressure recovery as the model velocity increased through the transonic region" (p. 1).

Report presenting measurements of downwash angles at points at two vertical positions at the probable tail location behind a high-aspect-ratio wing with an NACA 65-210 section with no sweep and 30 degrees and 45 degrees of sweepback and sweepforward in conjunction with a fuselage.

In the course of a rather cursory examination of the elution of tetra-positive ions from the cation exchange resin Dowex 50 with hydrochloric acid solutions, the authors have discovered a very effective method of separating zirconium from hafnimu. In view of the great labor involved in preparing even reasonably pure hafnium compounds by existing methods, they feel that this procedure will prove very valuable to those interested in obtaining hafnium compounds free of zirconium. Although the conditions which give satisfactory separation were first worked out using microgram amounts of material and the radioactive tracer technique, the run described here, involving milligrams of material, illustrates the applicability of the method to the production of significant amounts of pure hafnium and zirconium.

This report talks about aircraft design demand

The linear accelerator is again in operation after a shutdown fore repairs and minor changes. Radiofrequency checks of the instrument were made while the Van de Graaff was open. The vacuum of the system is now very good, the base pressure being 1.7 x 10{sup -6} mm Hg with a rate of rise of 800 s/{micro}s. Some preliminary results have been obtained on the activation of carbon with protons. The experiments were done using 10 mil, 50 mg/cm{sup 2} polystyrene discs. The activation curve obtained is shown. The break shown in the curve was found on two separate runs and it yet unexplained. In another experiment a proton induced activity in nickel was found. This had a 3.3 second half-life. Positive mesons have been detected on plates exposed in the 184-inch cyclotron with an arrangement shown schematically. The beam ws allowed to strike a 1/16 inch carbon target, and the mesons, which are bent around by the magnetic field, were detected with photographic plaes placed beneath the circulating beam. A series of experiments were done in which the plates were placed at distances varying from 1-1/2 to 3/4 inch from the beam between 1/4 inch plates of copper. The plates …

From abstract: "Critical assembly tests have been made on the Pajarito Universal Machine to determine the safety limits of handstacking cubes of 95% U-235 in spherical geometries preparatory to making critical assemblies of U-235 in an "infinite" tuballoy tamper. The U-235 cubes were stacked as pseudospheres in a cavity at the top of a tuballoy block 12" high and 8" on a side, and the assembly tamped by locating it inside a doughnut shaped water tank whose tamping effect is equivalent to the tamping caused by personnel necessary for hand stacking."

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, Price Daniel, regarding a legal question submitted for clarification: Authority to purchase and operate a County Tubercular Hospital from current funds.

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, Price Daniel, regarding a legal question submitted for clarification: The authority of the Commissioners' Court to apportion the automobile registration receipts equally among the four commissioners' precincts of the county.

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, Price Daniel, regarding a legal question submitted for clarification: The authority of the Commissioners' Court to apply the proceeds of a special hospital maintenance tax toward the construction of a county hospital.

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, Price Daniel, regarding a legal question submitted for clarification: The necessity for releases from both natural parents in order to adopt a child whose parents are divorced.

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, Price Daniel, regarding a legal question submitted for clarification: Basis for computation of occupation tax on production of carbon black produced by Witco Hydrocarbon Corporation under contract with Witco Chemical Company.