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THE HEAT CAPACITY OF BERYLLIUM CARBIDE POWDER IN STAINLESS STEEL CAPSULES AS A FUNCTION OF TEMPERATURE (400-1800 F)

Description: The mean heat capacity of a sample of powdered beryllium carbide, a possible moderator material for a nuclear reactor, was determined as a function of temperature. A thin-walled stainless steel capsule containing the material was heated in an electric furnace and dropped into a water calorimeter. The following linear equation for mean heat capacity over the temperature range 50 f C-T f C as a function of temperature, T, was derived from the data by the method of least squares: C/sub p/ = 0.299 … more
Date: April 20, 1949
Creator: Powers, H.; Kostigen, T. & Trice, J.B.
Item Type: Refine your search to only Report
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METHODS FOR THE ANALYSIS OF BERYLLIUM CARBIDE

Description: Analytical methods are given for determining the composition and impurities of beryllium carbide. A summary of the experimental work leading to these procedures and supporting data are also presented. Analytical procedures for the determination of free and combined carbon, moisture, nitrogen, beryllium oxide, silica, iron, total beryllium, and beryllium metal are outlined. Diagrams of special apparatus used are included. (auth)
Date: March 21, 1949
Creator: Bridges, W.L.; Funston, E.S. & Reed, S.A.
Item Type: Refine your search to only Report
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THE HEAT CAPACITY OF U$sub 3$O$sub 8$ POWDER AS A FUNCTION OF TEMPERATURE (400-1800 F)

Description: The mean heat capacity of a sample of powdered U/sub 3/O/sub 8/ was determined as a function of temperature from measurements of heat content. A thin-walled nickel capsule containing the material was heated in an electric furnace and dropped into a water calorimeter The Mean heat capacity values calculated from the experimental data were nearly constant over the temperature range, room temperture to 250-975 deg C (482-1790 deg F). The average value was 0.074 plus or minus 0.004 cal gm/sup -1EDE… more
Date: April 26, 1949
Creator: Powers, H.; Welch, F. & Trice, J.B.
Item Type: Refine your search to only Report
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Nitrogen 12

Description: N{sup 12} is shown to have a half life of 12.5 {+-} 1 milliseconds, and a positron upper limit of 16.6 {+-} 0.2 Mev. It is produced by the reaction C{sup 12}(p,n)N{sup 12}, and has a threshold proton energy of 20.0 Mev. This indicates that N{sup 12} is within about 200 Kev of being unstable against proton emission. The mass of N{sup 12} is 12.0228 {+-} 0.00015, and the beta transition is allowed.
Date: January 19, 1949
Creator: Alvarez, Luis W.
Item Type: Refine your search to only Report
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Experiments on the Effect of Atomic Electrons on the DecayConstant of Be7 II.

Description: A comparison of the decay constants of Be{sup 7} in beryllium oxide and in beryllium fluoride has given {lambda}{sub BeO}-{lambda}{sub BeF{sub 2}} = (+1.375 {+-} 0.053)10{sup -3}{lambda}{sub BeO} thus showing a definite effect of the chemical binding on the radioactive decay constant.
Date: June 15, 1949
Creator: Leininger, R. F.; Segre, E. & Wiegand, C.
Item Type: Refine your search to only Report
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Some Excitation Functions of Bismuth

Description: Excitation functions have been measured, using a 38-Mev alpha-beam and a 19-Mev deuteron beam for the following reactions: Bi({alpha},2n)At{sup 211}, Bi({alpha},3n)At{sup 210}, Bi(d,p)Ra E, Bi(d,n)Po{sup 210}, and Bi(d,3n)Po{sup 209}. The results are summarized in Figs. 4 and 5 and Tables I and II. A new isotope of astatine, At{sup 210}, has been identified; this isotope has a half life of 8.3 hr., decaying by K-capture to Po{sup 210} with the emission of a 1.0-Mev gamma-ray and a few conversio… more
Date: October 10, 1948
Creator: Kelly, E.L. & Segre, E.
Item Type: Refine your search to only Report
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Low Mass Francium and Emanation Isotopes of High AlphaStability

Description: Isotopes of francium with 126 or fewer neutrons have been looked for in bombardments of Th{sup 232} with 350 Mev protons from the 184-inch cyclotron. Fr{sup 212} with an apparent half-life of 19.3 minutes for branching decay by alpha emission (44%) to At{sup 208} and by orbital electron capture (56%) to Em{sup 212} has been found. Em{sup 212} is shown to be a 23-minute alpha-emitter. At{sup 208} decays primarily (99.5%) by orbital electron capture to Po{sup 208}, but shows 0.5% alpha-branching.… more
Date: October 10, 1949
Creator: Hyde, E. K.; Ghiorso, A. & Seaborg, G. T.
Item Type: Refine your search to only Report
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New Low Mass Isotopes of Emanation (Element 86)

Description: Among the spallation products obtained from the 350-Mev proton bombardment of Th{sup 232} they have identified two gaseous alpha-emitters which apparently do not decay into any presently known alpha-decay chains. The half-lives observed for the decay of the alpha-activities are 23 minutes and 2.1 hours. These half-lives may be principally determined by an unknown amount of orbital electron capture. At least one alpha-emitting daughter (about 4 hours half-life) has been observed to grow from a g… more
Date: September 5, 1949
Creator: Ghiorso, A.; Meinke, W. W. & Seaborg, G. T.
Item Type: Refine your search to only Report
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The Eight New Synthetic Elements

Description: In an early continuation of the investigation of the radioactive isotopes of element number 43 (technetium) Segre and Seaborg produced by the deuteron and neutron bombardment of molybdenum the isotope Tc{sup 99}, which they observed to decay by means of an isomeric transition with a half-life of 6.6 hours to a lower isomeric state with a half-life greater than 40 years. The upper isomeric state of this isotope was observed by Segre and C. S. Wu to be produced in the fission of uranium and more … more
Date: November 1, 1947
Creator: Seaborg, Glenn T.
Item Type: Refine your search to only Article
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Experiments of the Effect of Atomic Electrons on the DecayConstant of Be7

Description: In an attempt to detect a possible influence of the atomic electrons on the radioactive decay constant of Be{sup 7} they have measured {lambda}{sub Be}-{lambda}{sub BeO} and found (-3.0 {+-} 1.8) 10{sup -4} {lambda}{sub Be}. They describe also a method to measure mean lives of radioactive substances in a time short compared with the mean life.
Date: July 1, 1948
Creator: Segre, Emilio & Wiegand, Clyde
Item Type: Refine your search to only Report
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The Path of Carbon in Photosynthesis

Description: The dark fixation of carbon dioxide by green algae has been investigated and found to be closely related to photosynthesis fixation. By illumination in the absence of carbon dioxide followed by treatment with radioactive carbon dioxide in the dark, the amount fixed has been increased ten to twenty fold. This rate of maximum fixation approaches photosynthesis maximum rates. The majority of the radioactive products formed under these conditions have been identified and isolated and the distributi… more
Date: March 8, 1948
Creator: Calvin, M. & Benson, A. A.
Item Type: Refine your search to only Report
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Progress Report No. 62 June 1-15, 1948

Description: This paper reports on the following programs: (1) 184-inch Cyclotron Program; (2) 60-inch Cyclotron Program; (3) Synchrotron Program; (4) Linear Accelerator Program; (5) Experimental Physics; (6) Theoretical Physics; (7) Isotope Separation Program; (8) Chemistry; and (9) Medical Physics.
Date: June 30, 1948
Item Type: Refine your search to only Report
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Phosphorus Turnover and Photosynthesis

Description: The participation of phosphorus in biological oxidation-reduction reactions of the type found in glycolysis ADP + PO{sub 4}H{sup -} + 3-phosphoglyceraldehyde + DPN{sup +} = 3-phosphoglycerate{sup -} + 2H{sup +} + DPNH + ATP has suggested theories in which similar reactions are proposed for photosynthesis. In these theories the reducing power of photosynthesis is utilized not only for reduction of carbon dioxide but also, by means of coupled oxidations, for the generation of high-energy phosphat… more
Date: November 1, 1947
Creator: Aronoff, Sam & Calvin, Melvin
Item Type: Refine your search to only Report
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Systematics of Alpha-Radioactivity

Description: Correlations of alpha-decay energies in terms of mass number and atomic number have been made for all of the alpha-emitting species now numbering over 100. For each element isotopes show increase in alpha-energy with decrease in mass number except in the region of 126 neutrons where there is an explainable reversal. This reversal has the effect of creating a region of relatively low alpha-energy and long half-life at low mass numbers for such elements as astatine, emanation, francium, and possi… more
Date: September 12, 1949
Creator: Perlman, I.; Ghiorso, A. & Seaborg, G. T.
Item Type: Refine your search to only Report
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A Proposed Experimental Test of the Neutrino Theory

Description: The experiment outlined in this proposal has the possibility of giving an answer to the important question, 'Does the neutrino exist'? It is unfortunate that at the present time, there is no convincing experimental that neutrinos exist. Two recent articles review the status of various experiments which could give information about neutrinos. In general, these experiments give results in agreement with the predictions of beta decay theory. But actually, if even the most complete of the 'recoil t… more
Date: April 18, 1949
Creator: Alvarez, Luis W.
Item Type: Refine your search to only Report
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Artificial Collateral Chains to the Thorium and ActiniumFamilies

Description: The authors have produced and identified two new series of alpha-particle emitting radioactive elements; one is a 'collateral' branch of the actinium (4n + 3) radioactive family and the other is collateral to the thorium (4n) family. The series are of considerable interest in that they are the first whose early members lie on the neutron deficient side of beta stability. They have been produced in high yield of irradiation of thorium with deuterons of energy about {sup 80}Mev in the Berkeley 18… more
Date: July 1, 1948
Creator: Ghiorso, A.; Meinke, W. W. & Seaborg, G. T.
Item Type: Refine your search to only Report
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Monthly Progress Report No. 60 for April 1948

Description: This report gives a short summary of each of the following programs: (1) 184-inch Cyclotron Program; (2) 60-inch Cyclotron Program; (3) Synchrotron Program; (4) Linear Accelerator Program; (5) Experimental Physics; (6) Theoretical Physics; (7) Chemistry; (8) Medical Physics; and (9) Health Physics and Chemistry.
Date: May 1, 1948
Item Type: Refine your search to only Report
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Carrier-free Radioisotopes from Cyclotron Targets I. Preparation and Isolation of Sn113 and In114 from Cadmium

Description: 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 rep… more
Date: August 11, 1949
Creator: Maxwell, R. D.; Haymond, H. R.; Bobmberger, D. R.; Garrison, W. M. & Hamilton, J. G.
Item Type: Refine your search to only Report
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The Ion-Exchange Separation of Zirconium and Hafnium

Description: 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 cond… more
Date: October 11, 1948
Creator: Street, Kenneth, Jr. & Seaborg, Glenn T.
Item Type: Refine your search to only Report
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Half-Life for Double Beta-Decay

Description: Fireman(1) has reported the results of a rather difficult beta-particle coincidence counting experiment in which the decay of Sn{sup 124} by the simultaneous emission of two negative beta-particles, with a half-life between 0.4 x 10{sup 16} years and 0.9 x 10{sup 16} years, seems to have been observed. This note reports the results obtained from a different and somewhat simpler method of looking for the phenomenon of simultaneous emission of two beta-particles. These results are negative so far… more
Date: October 21, 1949
Creator: Levine, C. A.; Ghiorso, A. & Seaborg, G. T.
Item Type: Refine your search to only Report
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Paramagnetic Suseptibilities and Electronic Structure of AqueousCations of Elements 92 to 95

Description: Magnetic susceptibilities per gram atomic weight of elements 92 to 95 in most of their oxidation states were measured on 0.1 ml of solution which was 0.007 to 0.09 M in heavy element. The values obtained (all paramagnetic) in c.g.s. units x 10{sup 6} were: U(IV), 3690; Np(VI), 2060; Np(V), 4120; Np(IV), 4000; Pu(IV), 1610; Pu(III), 370; Am(III), 720. The results could be interpreted only on the basis of electronic configurations 5f{sup n}, even though susceptibilities were generally lower than … more
Date: November 12, 1948
Creator: Howland, Jerome J. & Calvin, Melvin
Item Type: Refine your search to only Report
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N-17, A Delayed Neutron Emitter

Description: The decay scheme of a 4.2 second neutron emitter has been investigated in detail. Chemical and physical evidence shows that it is N{sup 17}, which emits beta rays to a broad excited state of O{sup 17}, which then breaks up into a neutron plus O{sup 16}. The energy spectrum of the neutrons is determined by measuring the energies of the O{sup 16} recoils in a proportional counter. The neutrons have a most probable energy of 0.9 Mev, a 'half width' of less than .5 Mev, and an upper limit of about … more
Date: November 5, 1948
Creator: Alvarez, L. W.
Item Type: Refine your search to only Report
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