During this period the B Pile operated at its assigned power level of 25 MW below rated level, except for 10 hours on January 5. The operating level of the D Pile remained at 25 MW below rating. The rate gain in excess reactivity during equilibrium operation has been about 1.8 inhours/day. On January 1, the power level of the F Pile was dropped to 25 MW below rating from its previous rated level. Rod A was in a favorable position to make a determination of the reactivity coefficients at the time. The data does indicate an upper limit of {minus}0.21 ih/MW for the metal coefficient. An overall coefficient of 0.20 ih/MW was obtained. The unit was shut down on January 3 for discharge of 129 tubes of metal. A summary of the present reactivity states of the B, D, and F Piles are given. Iron content of process water for the three piles is also given.

This report divides the activities for November into three sections: D Pile; F Pile; and general physics. During November the D Pile was down twice for regularly scheduled shutdowns. Two scram occurred during the month, both of short duration. Five Special Request 15 tubes were discharged and recharged with Special Request 15. Some 13 inhour of reactivity were gained during the month. Vertical rod thimbles, 10 through 22, were tested. A Production Test was performed to determine the reactivity power coefficients of the F Pile at low power levels and with practically no xenon poison remaining. Additional experience in the use of temporary poison columns during an extended shutdown of the pile was obtained during the month. Four new bismuth columns were charged during the month and six tubes were charged with LiF. The F Pile had not yet returned to xenon equilibrium following the shutdown of November 27 at the end of the month, but conditions just prior to this shutdown indicate a loss of one inhour since October 31. Two sets of specimens were removed from the ``B`` Test Hole of the F Pile on November 4. Samples were also machined from graphite removed from the No. 9 …

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 review the work being conducted in the 300 area of the Hanford production facility for the month of January.

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)

From Introduction: "The results of two phases of this investigation, presented in references 1 and 2, have indicated possible ways of reducing hull drag without causing large changes in aerodynamic stability and hydrodynamic performance."

From Summary: "This report presents the aerodynamic measurements made during a Navy investigation conducted in the Langley 8-foot high speed tunnel to determine the actual human tolerance to wind blasts."

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.

Describes the types of "materials and hardware used in aircraft construction and repair."

"This manual is designed as a text for the instruction of airship student pilots .... to give the knowledge of aerodynamics essential to the operation of [lighter than air aircraft]."(Page 2.)

"An investigation was conducted in the Cleveland altitude wind tunnel to determine the aerodynamic characteristics and the oil delivery critical altitude of the oil-cooler installation of an XTB2D-1 airplane. The investigation was made with the propeller removed end with the engine operating at 1800 brake horsepower, an altitude of 15,000 feet (except for tests of oil-delivery critical altitude), oil-cooler flap deflections from -20 degrees to 20 degrees and inclinations of the thrust axis of 0 degrees, 1.5 degrees, and 6 degrees. At an inclination of the thrust axis of 0 degrees and with the propeller operating, the total-pressure recovery coefficient at the face of the oil cooler varied from 0.84 to 1.10 depending on the flap deflection" (p. 1).

"An investigation was made in the Cleveland Altitude wind tunnel to determine the performance of an Aeroproducts H20C-162-X11M2 four-blade propeller on a YP-47M airplane at high blade loadings and high engine powers. The propeller characteristics were obtained for a range of power coefficients from 0.30 to 1.00 at free-stream Mach numbers of 0.40 and 0.50. The results of the force measurements are indicative only of trends in propeller efficiency with changes in power coefficient and advance-diameter ratio because unknown interference effects existed during the investigation" (p. 1).

From Introduction: "Evaluation of tail-pipe burning in this engine with a larger tail-pipe combustion chamber is discussed in reference 1. Results of investigations on tail-pipe burning in this engine at static sea-level conditions are presented in reference 2. An investigation of thrust augmentation by means of injecting water at the inlet of an axial-flow compressor engine is discussed in reference 3."

From Introduction: "The purpose of the present paper is to summarize the available data on the effects of wing-fuselage-tail and wing-nacelle interference on the distribution of the air load among aircraft components. Some discussion is also given of the effects of center-of-gravity position."

Abstract: The erroneously high values for uranium content of salvage solutions as determined by the ether extraction-ascorbic acid procedure have been demonstrated to be due to the presence of colored organic materials in these solutions. Evaporation of such solutions to fumes of HC104 before extraction has been shown to be completely successful in preventing such interference while pretreatment with activated carbon is sufficiently successful for application in Control laboratories. Complete procedures for application of either protreatment and results of such application to composite salvage solutions received over a six-month period are included.

"A preliminary analytical investigation was made to determine the feasibility of the basic idea of controlled failure points as safety valves for the primary airplane structure. The present analysis considers the possibilities of the breakable wing tip which, in failing as a weak link, would relieve the bending moments on the wing structure. The analysis was carried out by computing the time histories of the wing and stabilizer angle of attack in a 10g pull-up for an XF8F airplane with tips fixed and comparing the results with those for the same maneuver, that is, elevator motion but with tips jettisoned at 8g" (p. 1).

The cyclotron is the only practical source of many carrier-free radioisotopes. The preparation and radiochemical isolation of a number of these activities, produced in the 60-inch cyclotron of Crocker Laboratory, will be presented in this paper and in subsequent papers of this series. In most cases the carrier-free radioisotopes were prepared for use in biological systems and the final preparations were in the form of isotonic saline solutions at a range of pH from 5 to 8. The present paper reports the radiochemical isolation of carrier-free Sn{sup 113} and In{sup 114} produced by bombarding cadmium with 38 Mev alpha-particles. At this energy, Sn{sup 113} and In{sup 114} are produced in a thick target by the nuclear reactions; Cd{sup 110}({alpha},n)Sn{sup 113}, Cd{sup 111}({alpha},2n)Sn{sup 113}, Cd{sup 112}({alpha},3n)Sn{sup 113}, Cd{sup 111}({alpha},p)In{sup 114}, Cd{sup 112}({alpha},pn) In{sup 114}. The shorter-lived tin and indium activities together with the possible radioisotopes of silver produced by (n,p) reactions, were allowed to decay out prior to the chemical separations.

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Technical report. Numerous application of various column adsorption techniques to inorganic analytical chemistry have appear in the literature. The comparatively recent introduction of ion exchange resins has resulted in the development of efficient, simple, and rapid column adsorption methods. the principal service of column adsorption methods to analytical chemistry is that of providing a relatively simple means of separating an element in a sufficiently pure state so that a direct precipitation, ignition, and weighting, for example, will suffice to complete the quantitative analysis. Systems involving uranyl nitrate will naturally be emphasized in this report but information will be included concerning the separation of the individual members of a series from one another, such as in the alkaline earths and the rare earths.

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.

None

From Summary: "Stability and control characteristics determined from tests in the Langley 19-foot pressure tunnel of a 0.2375-scale model of the Douglas XA-26 airplane are compared with those measured in flight tests of a Douglas A-26 airplane. Agreement regarding static longitudinal stability as indicated by the elevator-fixed neutral points and by the variation of elevator deflection in both straight and turning flight was found to be good except at speeds approaching the stall. At these low speeds the airplane possessed noticeably improved stability, which was attributed to pronounced stalling at the root of the production wing."

Report presenting a comparison of the vertical-tail loads determined from pressure-distribution measurements in flight in various maneuvers with the corresponding vertical-tail loads. Some of the maneuvers investigated included slow rolls, steady sideslips, fishtails, and rolling pull-outs.

"Computations were made to determine the temperature distribution and cooling of solid gas-turbine blades.A range of temperatures was used from 1500 degrees to 2500 degrees F, blade-root temperatures from 100 degrees to 1000 degrees F, blade thermal conductivity from 8 to 220 BTU/(hr)(sq ft)(degrees F/ft), and net gas to metal heat transfer coefficients from 75 to 250 BTU/(hr)(sq ft)(degrees F)" (p. 1).