The study of the interaction of the electromagnetic field with nuclei has proved very fruitful for the elucidation of many details of nuclear structure. The γ-ray transitions observed in either absorption or emission can be divided into three classes, depending on whether the matrix elements of the transition are (1) much larger, (2) approximately equal or (3) much smaller than those expected for single proton transitions which are usually taken as a norm. In class (1) we find (a) the broad transitions leading to the "giant resonances" in the nuclear photo-electric effect, and (b) the "fast" transitions between low lying states, especially for even-even nuclei far removed from magic numbers. The large matrix elements and the regular dependence of their magnitude on the atomic weight speak for cooperative phenomena in which many nucleons or the nuclei as a whole are involved. In class (2) we find the much studied M4 transitions which give strong support for the single particle model; they have rather uniform matrix elements. Some finer points remain to be understood, especially why some odd nuclei do not show the expected ratio for |M|^2 of ~ 2:1. The transitions belonging to class (3) require further selection rules and …

Uranium extraction of 95% has been obtained from samples of Temple Mountain ore by a cyclic test procedure in which the new feed was not roasted. This procedure involved acid leaching the ore, flotation and roasting of the carbonaceous material, and acid leaching the roaster calcine.

From Introduction: "Early in 1951 the National Advisory Committee for Aeronautics published, as Technical Note 2276 (ref. 1), a report by the Aluminum Research Laboratories of the Aluminum Company of America on the results of static and fatigue tests of high-strength aluminum alloy monobloc specimens and bolted joints. In view of special interest shown by several aircraft companies, certain expansions of the test program were undertaken by the Aluminum Research Laboratories and are reported herein."

An investigation has been made in the Langley low-turbulence pressure tunnel of the aerodynamic characteristics of the NACA 0012, 64(sub 2)-015, and 64(sub 3)-018 airfoil sections. Data were obtained at Mach numbers from 0.3 to that for tunnel choke, at angles of attack from -2deg to 30deg, and with the surface. of each airfoil smooth-and with roughness applied at the leading edge.The Reynolds numbers of the tests ranged from 0.8 x 10(exp 6) to 4.4 x 10(exp 6). The results are presented as variations of lift, drag, and quarter-chord pitching-moment coefficients with Mach number.

Report presenting theoretical performance characteristics and estimates of effective specific impulse and weight for rocket engines serving a main and booster power plants for missiles. The fuels used included ammonia-fluorine and JP4-oxygen propellants. At extremely high altitudes, the specific impulse depends primarily on the expansion ratio.

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A report about a previously published semiquantitative spectrographic method that was modified by applying microphotometric scanning of the spectrograms in such a way that the operator was free to do other work during a large part of the scanning time.

Report presenting the airplane drag problem at transonic and supersonic speeds. The area rule is shown to be a powerful tool that provides guidance for designers in selecting aerodynamic features compatible with low wave drag. Analytical methods have been developed that permit quantitative evaluation of the wave-drag level likely to be experienced with a given design.

This report addresses the basic research and particle accelerators.

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The Bevatron requires an intense source of high energy protons. The machine should accept monoenergetic protons for a duration of approximately 500 microseconds once every 6 seconds. To satisfy the requirements of small loss due to scattering by the gas in the accelerating chamber, a 9.9-Mev linear accelerator has been built and operated.

This report lists pertinent NACA papers presenting research results which have a direct bearing on control system design and performance for both piloted and automatically controlled aircraft. Limited reference is also made to NACA reports on aircraft engine controls and to research techniques and instrumentation pertinent to the study of control systems and aircraft dynamics in flight. Reports published between January 1949 and April 1954 are listed in chronological order and cross referenced.

Describes the most important and most common cereal smuts in the United States; also describes how to recognize and control diseases caused by smuts.

This report descrirs Chemical Properties of Elements 99 and 100

A description of some of the chemical properties and of the methods used in the separations of elements 99 and 100 is given. The new elements exhibit the properties expected for the tenth and eleventh actinide elements. Attempts to produce an oxidation state greater than 111 of element 99 have been successful. In normal aqueous media only the 111 state of element 100 appears to exist. The relative spacings of the elution peaks of the new elements in some separations with ion exchange resin columns are the same as the relative spacings of the homologous lanthanide elements. The results of experiments involving cation exchange resins with very concentrated hydrochloric acid eluant show that the new elements, like the earlier actinides, are more strongly complexed than the lanthanides. The new elements also exist partially as anions in concentrated hydrochloric acid, as do earlier actinide elements, and they may be partially separated from each other by means of ion exchange resins. With some eluants interesting reversals of elution positions are observed in the region Bk-Cf-99-100, indicating complex ion formation involving unusual factors.

The quantitative estimation of submicrogram amounts of boron in zirconium hydride using a colorimetric procedure is described. Solution of the sample in sulfuric acid or hydrofluoric acid and subsequent distillation of methyl borate without boron loss or contamination is shown to be possible. Using the curcumin color reaction, quantities of boron as low as 0.01 microgram can be detected. The method should apply equally well to zirconium metal and compounds, providing they can be dissolved under conditions that do not result in loss of boron and if the resulting solution will permit the quantitative removal of boron by distillation as methyl borate.

Report presenting a comparison of normal load factors measured during combat operations with those measured during an NACA flight program conducted with fully instrumented service airplanes in operational training. Results indicated that for an equal number of maneuvers, normal load factors obtained from the NACA program are greater than those obtained during combat when based on the service-limit load factor.

Memorandum presenting the compatibility of pentaborane with aluminum foil, 24S-T and 17S-T aluminum, and 50-50 tin-lead solder in the range of -30 to -50 degrees F for 7 hours, at 90 degrees F for 6.5 hours, and at 70 degrees F for 28 days. Results were evaluated by determination of the loss in weight after the test period, metallographic inspection, and comparison with blanks carried through test conditions without exposure to the liquid. The evaluation of results was made by visual inspection and physical tests of dimensional stability, tensile strength, elasticity, and gain or loss of weight.

From abstract: "In the present paper, the above methodology is investigated stochastic processes in general and it is shown how certain choices of sets can be made which preserve the linearity properties, though not necessarily the Markovian principles"

Report presenting a survey of various types of catapults in connection with the problem of accelerating a large car along a track to a speed of 150 miles per hour. A hydraulic jet catapult was found to be the best suited and various design problems of that type are treated. The expected propulsive efficiency of the catapult is given and the effect of a side wind on the jet trajectory is calculated.

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Abstract: In one of the final stages of the process at the Mallinckrodt Uranium Refining Center, a 45 per cent nitric acid solution at about 170 F is used to pickle the calcined magnesium fluoride scale off the uranium derbies. The increase in the fluoride-ion content of the bath tends to promote corrosion of the Type 347 stainless tanks. This attack becomes excessive if 0.3 g/liter of fluoride ion or more is present. It was found that if aluminum ion is added to the solution the corrosiveness of the bath can be controlled. Two or three times as much aluminum ion as fluoride ion present is found satisfactory at 170 F. Indications are that the tying up of the fluoride-ion by the complexion [AlF6]8 is responsible for the corrosion control.

Monthly newsletter of the High Plains Underground Water Conservation District No. 1, discussing the field of underground water. Topics include profiles of water conservation research, annual pre-plant soil moisture survey data, annual Winter Water Level measurement data, and information about the latest water conservation tips.