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THE METABOLSIM AND TOXICITY OF RADIUM-223 IN RATS

Description: This report covers studies of the excretion and retention of 'tracer' and toxic doses of the 11.2-day Ra{sup 223} isotope, its acute toxicity (organ weight changes, gross and microscopic pathology, and Fe{sup 59} utilization by the bone marrow), and long-term histopathological changes and alterations in the hemogram.
Date: February 21, 1958
Creator: Durbin, Patricia; Durbin, Patricia W.; Asling, C. Willet.; Jeung, Nylan; Williams, Marilyn H.; Post, James. et al.
Partner: UNT Libraries Government Documents Department

Meeting XI Bevatron Research Conference

Description: It will be desirable to have a general purpose bending magnet available for use with the Bevatron. The design discussed, while tentative, is believed to incorporate most of the desired properties for use with the external beam.
Date: January 12, 1954
Creator: Wenzel, William A.
Partner: UNT Libraries Government Documents Department

The Chelate Process, VI. Process flow involving o-dichlorobenzeneas the solvent for TTA

Description: Comparative studies of a series of halogenated solvents, as carriers for TTA in the chelate process for plutonium extraction, indicate that ortho-dichlorobenzene most nearly satisfies the requirements that are set forth. A complete process design is presented for use with this solvent, and flow data and equipment capacities are given for dissolver solution and for uranium-free fission product solution as alternate feeds to the process. Vertical mixer-settlers are recommended as the contractors, although pulsed columns or packed columns are also believed to be suitable. The size of such units is estimated from the best available rate and equilibrium data, and the effects of several operating variable are considered.
Date: January 1, 1951
Creator: Davis Jr., M.W.; Hicks, T.E. & Vermeulen, T.
Partner: UNT Libraries Government Documents Department

The occurrence of plutonium in nature

Description: Plutonium has been chemically separated from seven different ores and the ratios of plutonium to uranium determined. This ratio was found to be fairly constant in pitchblende and monazite ores, in which the uranium content varied from 50% t o 0.24%, and substantially less in carnotite and fergusonite.
Date: November 29, 1950
Creator: Levine, Charles A. & Seaborg, Glenn T.
Partner: UNT Libraries Government Documents Department

Spontaneous Fission

Description: The first attempt to discover spontaneous fission in uranium was made by Libby, who, however, failed to detect it on account of the smallness of effect. In 1940, Petrzhak and Flerov, using more sensitive methods, discovered spontaneous fission in uranium and gave some rough estimates of the spontaneous fission decay constant of this substance. Subsequently, extensive experimental work on the subject has been performed by several investigators and will be quoted in the various sections. Bohr and Wheeler have given a theory of the effect based on the usual ideas of penetration of potential barriers. On this project spontaneous fission has been studied for the past several years in an effort to obtain a complete picture of the phenomenon. For this purpose the spontaneous fission decay constants {lambda} have been measured for separated isotopes of the heavy elements wherever possible. Moreover, the number {nu} of neutrons emitted per fission has been measured wherever feasible, and other characteristics of the spontaneous fission process have been studied. This report summarizes the spontaneous fission work done at Los Alamos up to January 1, 1945. A chronological record of the work is contained in the Los Alamos monthly reports.
Date: November 22, 1950
Creator: Segre, Emilio
Partner: UNT Libraries Government Documents Department

A MEASUREMENT OF THE POSITIVE pi- Mu DECAY LIFETIME

Description: The lifetime for the decay of a {pi} meson into {mu} meson and neutral particle was first measured by Richardson and later by Martinelli and Panofsky. The method was the same in both cases: The fraction of {pi} mesons surviving various times of flight is measured by placing photographic detectors at various path lengths from the target. In the experiment reported here we observe the time lag between the two bursts of fluorescence due to mesons decaying in a scintillation crystal. The first burst is due to the stopping of the entering {pi} meson, the second to the {mu}-meson. As is shown in Fig. 1, a particle penetrating the first and into the second crystal starts the sweep (10{sup -8} sec/mm) of an oscilloscope. The pulses in the second crystal are delayed 0.5 x 10{sup -6} sec to allow the sweep to start and brighten and are then photographed. If the responsible particle is a {pi}{sup +} meson which stops in the crystal, it undergoes {pi}-{mu} decay and two pulses appear on the trace. The {mu}{sup +} meson has a range of only 2 mm in the crystal. If its decay electron is detected some time (.5-2.5 x 10{sup -6} sec) later; a neon light flashes and is photographed together with the scope trace. Only such marked traces are measured. Of these marked traces, 650 or roughly one-half, show the two pulses of the {pi}-{mu} event. Five percent are calculated to be due to random delayed coincidences, and another 3 percent due to {pi} mesons which have decayed in flight and come to rest in the second crystal as {mu} mesons. The remaining traces are due to {pi}{mu} decays which are too fast to be resolved. The sweep speed of the oscilloscope is calibrated periodically with an oscillator of known ...
Date: May 10, 1950
Creator: Chamberlain, O.; Mozely, R.F.; Steinberger, J. & Wiegand, C.
Partner: UNT Libraries Government Documents Department

The Mechanism of Proton Polarization in High-EnergyCollisions

Description: Recently experimental evidence has accumulated showing that high-energy collisions of protons with various nuclei induce a considerable polarization in proton beams, and a mechanism has been proposed to account for this effect.
Date: June 9, 1954
Creator: Chamberlain, Owen; Segre, Emilio; Tripp, Robert; Wiegand, Clyde & Ypsilantis, Thomas
Partner: UNT Libraries Government Documents Department

Medical and Health Physics Quarterly Report October, November, andDecember, 1950

Description: A considerable volume of work was accomplished during the past three months in the tracer program, experiments being conducted with At{sup 211}, carrier-free Bi{sup 206}, carrier-free Mn{sup 52}, carrier-free Mo{sup 93,99}, Np{sup 237}, Ta{sup 182} of a fair degree of specific activity, carrier-free Sc{sup 46}, and high specific activity Tm{sup 170}.
Date: February 27, 1951
Creator: Biology, Health and
Partner: UNT Libraries Government Documents Department

The Metabolism of 2-Caroboxy-4-Ketopentitol Diphosphate

Description: 2-Carboxy-4-ketopentitol is converted enzymatically by a cell-free preparation from spinach leaves into a substance undergoing acid-lactone interconversion. This substance has no phosphate or letone group and is probably a dicarboxylic, six-carbon sugar acid or the saccharic or saccharinic acid type. The significance of these findings with regard to the metabolic role of 2-carboxy-4-ketopentitol diphosphate is discussed.
Date: July 15, 1958
Creator: Moses, V. & Calvin, M.
Partner: UNT Libraries Government Documents Department

Carbon Dioxide Fixation by Microorganisms

Description: Resting cells of eleven microorganisms were exposed to radioactive carbon dioxide for 40 minutes. The radioactive compounds formed during this time were separated and identified by paper chromatography. Resting cells of Lactobacillus casei fixed no carbon dioxide and growing cells fixed carbon dioxide primarily in malic and aspartic acids. All of the radioactive compounds formed could have become radioactive by reversal of known decarboxylation reactions.
Date: July 24, 1951
Creator: Lynch, Victoria H. & Calvin, Melvin
Partner: UNT Libraries Government Documents Department

CARBOXYLATIONS AND DECARBOXYLATIONS

Description: A brief survey of decarboxylation reactions and carboxylation reactions that are known or presumed in biological systems will be presented. While a considerable number of amino acid decarboxylations are known, their mechanisms will not be included in the present discussion but will be reserved for a later paper in the symposium. The remaining decarboxylation reactions may be subdivided into oxidative and nonoxidative decarboxylations. In most cases, these reactions are practically irreversible except when coupled with suitable energy-yielding systems. The carboxylation reactions which are useful in the formation of carbon-carbon bonds in biological systems seem to fall into two or three groups: those which exhibit an apparent ATP requirement, and those which exhibit a reduced pyridine nucleotide requirement, and those which exhibit no apparent ATP requirement. Of the first group at least four cases, and possibly six or seven, are known, and one interpretation of them involves the preliminary formation of 'active' carbon dioxide, generally in the form of a carbonic acid-phosphoric acid anhydride. Those exhibiting no apparent ATP requirement seem to be susceptible to classifications as enol carboxylations in which the energy level of the substrate compound is high, rather than that of the carbon dioxide. There appear to be at least three examples of this latter type known, amongs them being the carboxy-dismutase reaction of ribulose diphosphate with carbon dioxide.
Date: April 21, 1959
Creator: Calvin, Melvin & Pon, Ning G.
Partner: UNT Libraries Government Documents Department

The Catalysis of Nuclear Reactions by mu Mesons

Description: In the course of a recent experiment involving the stopping of negative K mesons in a 10-inch liquid hydrogen bubble chamber, an interesting new reaction was observed to take place. The chamber is traversed by many more negative {mu} mesons than K mesons, so that in the last 75,000 photographs, approximately 2500 {mu}{sup -} decays at rest have been observed. In the same pictures, several hundred {pi}{sup -} mesons have been observed to disappear at rest, presumably by one of the ''Panofsky reactions''. For tracks longer than 10 cm, it is possible to distinguish a stopping {mu} meson from a stopping {pi} meson by comparing its curved path (in a field of 11,000 gauss) with that of a calculated template. In addition to the normal {pi}{sup -} and {mu}{sup -} stoppings, we have observed 15 cases in which what appears (from curvature measurement) to be a {mu}{sup -} meson comes to rest in the hydrogen, and then gives rise to a secondary negative particle of 1.7 cm range, which in turn decays by emitting an electron. (A 4.1-Mev {mu} meson from {pi} - {mu} decay has a range of 1.0 cm.) The energy spectrum of the electrons from these 15 secondary particles looks remarkably like that of the {mu} meson. There are four electrons in the energy range 50 to 55 Mev, and none higher; the other electrons have energies varying from 50 Mev to 13 Mev. The most convincing proof that the primary particle actually comes to rest, and does not--for example--have a large resonant cross section for scattering at a residual range of 1.7 cm, is the following: In five of the 15 special events, there is a large gap between the last bubble of the primary track and the first bubble of the secondary track. This gap ...
Date: December 10, 1956
Creator: Alvarez, L.W.; Bradner, H.; Crawford Jr, F.S.; Crawford, J.A.; Falk-Vairant, P.; Good, M.L. et al.
Partner: UNT Libraries Government Documents Department

Chemical and Photochemical Reactions of Thioctic Acid and RelatedDisulfides

Description: The carbon cycle of photosynthesis is briefly reviewed in its entirety and the experiments involving it which led to the implication of disulfide rupture in photosynthesis are indicated. A review of the organic, physical and photochemistry of disulfides, with particular reference to the five-membered disulfide rings as they appear in thioctic acid, is given.
Date: June 10, 1954
Creator: Calvin, Melvin
Partner: UNT Libraries Government Documents Department

Chemical Evolution and the Origin of Life

Description: The formation of more complex carbon compounds from simple ones through the action of radiation is used in an interpretation of the original formation of such compounds on earth. The relation of plants and animals and evolution of photosynthesis is discussed in the light of the participation of sulfur compounds in the metabolism of both group.
Date: March 10, 1953
Creator: Calvin, Melvin
Partner: UNT Libraries Government Documents Department

Example of an Antiproton-Nucleon Annihilation

Description: The existence of antiprotons has recently been demonstrated at the Berkeley Bevatron by a counter experiment. The antiprotons were found among the momentum-analyzed (1190 Mev/c) negative particles emitted by a copper target bombarded by 6.2-Bev protons. Concurrently with the counter experiment, stacks of nuclear emulsions were exposed in the beam adjusted to 1090 Mev/c negative particles in an experiment designed to observe the properties of antiprotons when coming to rest. This required a 132 g/cm2 copper absorber to slow down the antiprotons sufficiently to stop them in the emulsion stack. Only one antiproton was found in stacks in which seven were expected, assuming a geometric interaction cross section for antiprotons in copper. It has now been found that the cross section in copper is about twice geometric, which explains this low yield.
Date: February 27, 1956
Creator: Chamberlain, O.; Chupp, W.W.; Ekspong, A.G.; Goldhaber, G.; Goldhaber, S.; Lofgren, E.J. et al.
Partner: UNT Libraries Government Documents Department

Experiences with the Bevatron

Description: The Bevatron is still undergoing a process of gradual improvement to increase both the magnitude of the beam and the reliability. The operating conditions for optimum adjustment at the present stage of development are summarized.
Date: April 5, 1956
Creator: Lofgren, Edward J.
Partner: UNT Libraries Government Documents Department

The Luminescence of Chlorophyll-Containing Plant Material

Description: The luminescence of various chlorophyll-containing plant materials has been investigated under a variety of conditions. The results have been shown to be consistent with a mechanism involving the recombination of electrons and holes trapped in a quasi-crystalline lattice. Some details of such a mechanism have been proposed which suggest the mode of entry of the light energy into the photosynthetic pathway.
Date: July 1, 1957
Creator: Tollin, Gordon & Calvin, Melvin
Partner: UNT Libraries Government Documents Department

Metabolism of Thioctic Acid in Algae

Description: Thioctic acid labeled with sulfur-35 has been prepared and i t s metabolism b y algae has been studied. It i s converted by the algae into a number of forms, all of which upon hydrolysis yield either the disulfide o r i t s sulfoxide. One of these constituted the major portion of the labeled material in the chloroplasts. Aerobic metabolism for some minutes i s required to produce this form. Preliminary studies of the chemical nature of this form suggest i t to be esterified on the carboxyl group with a moiety of very high lipid solubility.
Date: April 17, 1956
Creator: Grisebach, Hans; Fuller, R.C. & Calvin, M.
Partner: UNT Libraries Government Documents Department