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Acoustics of a nonhomogeneous moving medium.

Description: Theoretical basis of the acoustics of a moving nonhomogeneous medium is considered in this report. Experiments that illustrate or confirm some of the theoretical explanation or derivation of these acoustics are also included.
Date: February 1956
Creator: Blokhintsev, D I

Action and Emission Spectra of the Luminescence of Green PlantMaterials

Description: The action and emission spectra of the delayed light emission from Chlorella, Nostoc, and spinach chloroplasts have been measured. The action spectra for Chlorella and for spinach chloroplasts are quite similar to the absorption spectra of these materials. The action spectrum for Nostoc, on the other hand, shows a relatively low activity for chlorophyll and carotenoids and a high activity for phycocyanin. The emission spectra of these materials demonstrates that the luminescence is the result of a transition between the first excited singlet state and the ground state of chlorophyll. Low-temperature studies suggest that the triplet state of chlorophyll is not involved at all in the luminescence of spinach chloroplasts. There is some indication that part of the light emitted from Nostoc is due to a phycocyanin transition.
Date: December 29, 1957
Creator: Tollin, G.; Fujimori, E. & Calvin, Melvin


Description: Activities at the Michigan Reactor and pneumatic tube system are outlined. Various modifications including installation and operation of a "bunny" rabbit pneumatic tube system for transferring samples from laboratory to counter are described. Prelimirary investigation for design of a neutron generator for activation work is described. Modifications to the 100-channel pulse-height analyzer including addition of auxillary circuits and additioral detectors are sumnnarized. In nuclear chemistry a cyclotron bombardment to produce long-lived vanadium tracer for yield determinations in activation analysis is described. Summaries of project work which have been published on absolute (d, alpha) reaction cross sections and excitation functions, use of computers in nuclear data analysis, and research on Ir/sup 196/ are presented. Study of the gamma spectra of 33-second Kr/sup 90/, 41-second Xe/sup 139/, and some longer-lived fission product rare gases is reported and a summary of preliminary results is given. Detection of a long-lived isomer of Ag/sup 108/ in old Ag/sup 110m/ samples is reported and new values for the branching ratios of 2.4minute Ag/sup 108/ are given. Activities of the Subcommittee on Radiochemistry are summarized. Development of a radiochemical procedure by the use of amalgam exchange is reported and exchange of the elements Cd, Tl, Zn, Pb, Bi, Sr, In, and Sn was demonstrated. Methods of expressing the efficiency of radiochemical separations are defined and presented tabularly. Application of activation analysis for many types of systems is reported. Data from activation analysis for trace constituents in meteorites, vanadium in petroleum process streams and in petroleum catalysts are presented. Activation analysis of niobium, rhenium, gold, and thalllum are also described. Information on personnel, published reports, and committee meetings is included. (For preceding period see AECU-3887.) (J.R.D.)
Date: November 1, 1959
Creator: Maddock, R.S. & Meinke, W.W. eds.

Activation Energy for Fission

Description: The experimentally determined exponential dependence of spontaneous fission rate on Z{sup 2}/A has been used to derive an expression for the dependence of the fission activation energy on Z{sup 2}/A. This expression has been used to calculate the activation energy for slow neutron induced fission and photofission. The correlation with the experimental data on these types of fission seems to be quite good.
Date: August 29, 1952
Creator: Seaborg, Glenn T.

An active particle diffusion theory of flame quenching for laminar flames / Dorothy M. Simon and Frank E. Belles

Description: An equation for quenching distance based on the destruction of chain carriers by the surface is derived. The equation expresses the quenching distance in terms of the diffusion coefficients and partial pressures of the chain carriers and gas phase molecules, the efficiency of the surface as a chain breaker, the total pressure of the mixture, and a constant which depends on the geometry of the quenching surface. Quenching distances measured by flashback for propane-air flames are shown to be consistent with the mechanism. The derived equation is used with the lean inflammability limit and a rate constant calculated from burning velocity data to estimate quenching distances for propane-air (hydrocarbon lean) flames satisfactorily.
Date: March 4, 1952
Creator: Simon, Dorothy M & Belles, Frank E


Description: The carbonate and organic leaching processes for the recovery of U from its ores are outlined. The Excer prccess (ion-exchange conversion and electrolytic reduction) and the Fluorox process (starch-- HF reaction) for the production of UF/sub 4/ from ore concentrate and depleted reactor fuels are described. The fluidized-bed process for UF/sub 4/ production from UO/sub 2/(NO/ sub 3/)/sub 2/ is also described. Methods for improving the reactivity of UO/sub 3/ and mechanical and thermal processes for increasing the density of UF/sub 4/ were investigated. Applications of fluoride volatility prccesses to feed materials are discussed. (C.W.H.)
Date: January 1, 1956

The acute radiation syndrome: A study of ten cases and a review of the problem

Description: In this report ten cases of acute radiation syndrome are described resulting from two accidents occurring at the Los Alamos Scientific Laboratory of unique nature involving fissionable material. These cases are described in considerable detail. The report comprises ten sections. This volume, part II of the report, is comprised of sections entitled: (1) the Biological Basis for the Clinical Response seen in the Acute radiation Syndrome, (2) Clinical Signs and Symptoms, (3) Discussion of Hematological Findings, (4) Chemistry of the Blood and Urine, (5) Discussion of Pathological Findings, and (6) Reconsiderations of the Calculated Radiation Doses in Terms of the Observed Biological Response of the Patients. This report was prepared primarily for the clinician who is interested in radiation injuries and therefore emphasis has been placed on the correlation of clinical and pathological changes with the type of cytogenetic change known to be produced by ionizing radiation.
Date: March 17, 1950
Creator: Hempelmann, L.H. & Lisco, H.

S-Acyl Thioctic Acid Derivatives in Aerobacter Aerogenes andScenedesmus

Description: 1. Acetyl thioctic acid has been prepared chemically and i t s chromatographic and acetylating behavior i s described. 2. A C{sup 14} -containing substance has been found in Scenedesmus, photosynthesizing in the presence of a-C{sup 14}-pyruvate, which has properties suggesting that it i s acetyl thioctic acid. 3 . A C{sup 14}-containing substance has been found in Aerobacter aerogenes, metabolizing a-C{sup 14}-pyruvate, which shows the properties of a labile conjugate of thioctic acid with some relatively polar groups. 4. Acetyl thioctic acid i s formed in vitro when light acts on a solution of thioctic acid and pyruvate.
Date: March 30, 1955
Creator: Milhaud, Gerard; Benson, Andrew A.; Fuller, R. Clinton; Milhaud,Vera & Calvin, M.

Adams disassembly procedure for Bldg. 10, Nevada Test Site

Description: The disassembly of the `Adams` primary was scheduled for April 28, 29, and 30, 1959. The method of disassembly is provided as a procedure to be accomplished in order and the time and initials of the person accomplishing each step recorded.
Date: April 24, 1959
Creator: Beckman, K. F.

Adaptation of a Cascade Impactor to Flight Measurement of Droplet Size in Clouds

Description: A cascade impactor, an instrument for obtaining: the size distribution of droplets borne in a low-velocity air stream, was adapted for flight cloud droplet-size studies. The air containing the droplets was slowed down from flight speed by a diffuser to the inlet-air velocity of the impactor. The droplets that enter the impactor impinge on four slides coated with magnesium oxide. Each slide catches a different size range. The relation between the size of droplet impressions and the droplet size was evaluated so that the droplet-size distributions may be found from these slides. The magnesium oxide coating provides a permanent record. of the droplet impression that is not affected by droplet evaporation after the. droplets have impinged.
Date: September 18, 1951
Creator: Levine, Joseph & Kleinknecht, Kenneth S.

Adaptation of Combustion Principles to Aircraft Propulsion, Volume 2, Combustion in Air-Breathing Jet Engines

Description: This volume continues the NACA study of combustion principles for aircraft propulsion. The various aspects of combustion pertinent to jet engines are organized and interpreted with quite extensive information, particularly for basic or fundamental. subject matter. The report concerns only air-breathing engines and hydrocarbon fuels, and not rocket engines and high-energy fuels. Since the references have been selected to illustrate important points, the bibliographies, while thorough, are not complete. This volumes describes the observed performance and design problems of engine combustors of the principal types. These include combustor-inlet conditions; starting, acceleration, combustion limits, combustion efficiency, coke deposits, and smoke formation in turbojets; ram-jet performance; and afterburner performance and design.
Date: May 2, 1956

Adaptation of Combustion Principles to Aircraft Propulsion, Volume I, Basic Considerations in the Combustion of Hydrocarbon Fuels with Air

Description: The report summarizes source material on combustion for flight-propulsion engineers. First, several chapters review fundamental processes such as fuel-air mixture preparation, gas flow and mixing, flammability and ignition, flame propagation in both homogenous and heterogenous media, flame stabilization, combustion oscillations, and smoke and carbon formation. The practical significance and the relation of these processes to theory are presented. A second series of chapters describes the observed performance and design problems of engine combustors of the principal types. An attempt is made to interpret performance in terms of the fundamental processes and theories previously reviewed. Third, the design of high-speed combustion systems is discussed. Combustor design principles that can be established from basic considerations and from experience with actual combustors are described. Finally, future requirements for aircraft engine combustion systems are examined.
Date: April 1, 1955
Creator: Barnett, Henry C. & Hibbard, Robert R.

Addition of standard quantities of chemicals in certain reduction operations in the 234-5 Building

Description: A proposal by ``S`` Division that operations be simplified by adding fixed amounts of calcium and iodine in the reduction step as a time saving device has been investigated. Ten test runs in the 410--430 gram range have been compared with twenty normal runs made in this period. The average yields were 98.27% for the normal method and 98.26% for the test runs. No effect on individual yields by the variance in percent calcium and the iodine ratio was observed. Seventy percent of the runs normally fall into the 410--430 gram range. By controlled compositing of the feed batches, it should be possible to increase the percentage of the PuF{sub 4} runs that fall in this range.
Date: September 28, 1951
Creator: Desposato, F.E.