A low temperature adiabatic cryostat for determining precise calorimetric data has been described. The accuracy of the data produced by this apparatus has been established by measuring the thermal properties of n-hexane up to 300 deg K. These data agree with available precise data, in general, to within 0.2%. The precision of the heat capacity measurements is, for the most part, better than 0.1%. (auth)

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As titanium, zirconium, and other of the high melting electropositive metals become more important, the problem of using suitable refractory materials for their casting becomes more important. This paper discusses the method of choosing and testing possible container materials. To make the discussion more specific, titanium is used as an example. As titanium melt at 2000 {+-} 10 K, it is immediately clear that one is restricted to refractory materials melting considerably above 2000 K. This greatly limits the possible materials that might be considered. The possibility of using any pure high melting element can be quickly eliminated as titanium reacts quite vigorously with non-metals such as carbon and due to its high boiling point and therefore high internal pressure, one can predict that it dissolves even the most refractory metals. Examination of phase diagrams confirms that even metals such as tantalum, tungsten, and rhenium would not be able to resist attack by titanium. One is thus limited to high melting compounds such as the oxides, sulfides, nitrides, carbides, silicides, and borides. The first consideration is that, if possible, one would use a compound which is thermodynamically stable in the presence of titanium metal at 2000 K. Titanium should not …

This report consists of graphs and charts exhibited at the Chemical Development Section Deentrainment Seminar on June 2, 1950.

This is a progress report of the production reactors on the Hanford Reservation for the month of May 1950. This report takes each division (e.g., manufacturing, medical, accounting, occupational safety, security, reactor operations, etc.) of the site and summarizes its accomplishments and employee relations for that month.

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The microgram scale isolation and preparation of pure compounds of americium is described. Data are presented to show that the alpha-half-life of the isotope Am{sup 241} is 490 {+-} 14 years. The absorption spectrum of Am(III) in 1M nitric acid in the range 3500-8000 mu is given. The wave lengths of 10 of the most prominent lines in the copper spark emission spectrum of americium are given to the nearest 0.01 {angstrom}. Evidence is presented to show that the potential for the Am(III)-Am(IV) couple in acid solution is more negative than -2v and that the potential for the Am(II)-Am(III) couple is more positive than +0.9v.

This is a progress report of the production reactors on the Hanford Reservation for the month of June 1950. This report takes each division (e.g., manufacturing, medical, accounting, occupational safety, security, reactor operations, etc.) of the site and summarizes its accomplishments and employee relations for that month.

The gas exchange by barley leaves of oxygen, carbon dioxide, and added radiocarbon dioxide has been measured in a closed system, with the following results: 1. Carbon dioxide follows different but not necessarily independent paths in photosynthesis and light respiration. 2. The carbon of newly formed photosynthetic intermediates is not available for respiration while the light is on, but becomes immediately respirable in the dark, The enhancement of dark respiration after a light period is largely due to built-up ''photosynthates.'' 3. Photosynthesis proceeds at a measurable rate even at the lowest CO{sub 2} pressures observed (0.03 mm Hg). There is no evidence for a ''threshold'' concentration of carbon dioxide for the reaction; at the lowest concentrations reached, respiration exactly equals assimilation, 4. The mean rate of respiratory CO{sub 2} evolution in strong light was found to be less than that in the dark. Internal re-photosynthesis of respiratory carbon may have been sufficient to account for this effect. 5. The assimilation of C{sup 14}O{sub 2} is about 17% slower than that of C{sup 12}O{sub 2}.

This is a progress report of the production reactors on the Hanford Reservation for the month of September 1950. This report takes each division (e.g., manufacturing, medical, accounting, occupational safety, security, reactor operations, etc.) of the site and summarizes its accomplishments and employee relations for that month.

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This is a progress report of the production reactors on the Hanford Reservation for the month of October 1950. This report takes each division (e.g., manufacturing, medical, accounting, occupational safety, security, reactor operations, etc.) of the site and summarizes its accomplishments and employee relations for that month.

This is a progress report of the production reactors on the Hanford Reservation for the month of November 1950. This report takes each division (e.g. manufacturing, medical, accounting, occupational safety, security, reactor operations, etc.) of the site and summarizes its accomplishments and employee relations for that month.

Spectrographic analyses of plutonium metal are discussed.

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This is a progress report of the production on the Hanford Reservation for the month of February 1951. This report takes each division (e.g., manufacturing, medical, accounting, occupational safety, security, reactor operations, etc.) of the site and summarizes its accomplishments and employee relations for that month.

Thorium forms a tetragonal lower hydride of composition ThH{sub 2}. The hydrides ThH{sub 2}, ThD{sub 2} and ZrD{sub 2} have been studied by neutron diffraction in order that hydrogen positions could be determined. The hydrides are isomorphous, and have a deformed fluorite structure. Metal-hydrogen distances in thorium hydride are unusually large, as in UH{sub 3}. Thorium and zirconium scattering amplitudes and a revised scattering amplitude for deuterium are reported.

It is generally believed that charged particles cannot be accelerated from ground potential to ground potential unless they pass through a system which has associated iwth it a time varying magnetic field. D.C. electric fields must satisfy the equation {contour_integral} Eds = 0, while the time varying fields used in radio-frequency accelerators and betatrons are freed from this restriction of scalar potential theory. In 1932, AJ Dempster produced protons with an energy of 45 Kev, by passing them from an electrode at +22.5 kv dc to ground. The protons were first accelerated to ground potential, with an energy gain of 22.5 kev. A small fraction of the protons then picked up an electron from a residual gas molecule, and ''coasted'' to a second electrode at +22.5 kv. Then a small fraction of these neutral hydrogen atoms lost their electrons, and were accelerated to ground with a second gain in energy equal to 22.5 kev. An accelerator of this type is obviously impractical for several reasons. The probability of neutralizing a proton varies inversely with a high power of the particle velocity, so the scheme would not work at energies of interest to nuclear physicists. Even at the low energies where …

This is a progress report of the production reactors on the Hanford Reservation for the month of March 1951. This report takes each division (e.g., manufacturing, medical, accounting, occupational safety, security, reactor operations, etc.) of the site and summarizes its accomplishments and employee relations for that month.

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