7 research outputs found
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Proceedings of workshop on scale control in geothermal energy extraction systems
Nine papers are included. Separate abstracts were prepared for eight and one was listed by title. Also included are the workshop recommendations for research needs. (MHR
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Thermochemical correlation of material transport in an alkali metal heat pipe
The use of high-power heat pipes in space power systems requires a means of life prediction. The design lifetimes required make experimental determination of life impractical. Thermochemical modeling of heat pipe corrosive failure modes has been investigated as a means of making such prediction. Results have been applied to tests of molybdenum-lithium heat pipes operating from 1400 to 1500/sup 0/K. A free energy minimization routine coupled to a hydrodynamic model of the operating heat pipe has been used to give local equilibrium values of reaction products as a function of operating time. The predicted reactions for critical regions of the heat pipe were compared with limited results of post-test examinations. Corrosive damage to the heat pipe wick structure was correlated with high oxygen and nitrogen activity in the evaporator region of the heat pipe
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Kinetics of an H--F explosion as initiated by a pulse of fluorine atoms
The elementary reactions occurring in an H/sub 2/-F/sub 2/ explosion are given with each vibrational level of H/sub 2/ and HF considered as a separate reacting species. Rate coefficients for all the elementary reactions are either estimated or calculated, and the major assumptions entering into the determination of each rate coefficient are given. The effect of non-Maxwell distributions in the translational energies of some of the species is estimated. For strong pulses of F atoms, the explosion is complete before any appreciable contribution to the rate is made by thermal dissociation of F/sub 2/ or H/sub 2/. (auth
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THERMODYNAMICS OF CERTAIN REFRACTORY COMPOUNDS. PART II. CONTINUED THEORETICAL AND EXPERIMENTAL STUDIES ON AN EXTENDED LIST. Second Quarterly Progress Report, September 1 to November 30, 1963
The thermodynamic properties of refractory borides, carbides, nitrides, and oxides of some 31 elements are compiled. Several tables for elements and compounds not previously reported are presented, and the experimental spectroscopic studies of the vapor of boron oxide and hydroxide are discussed. (R.J.S.
Benefits of organic farming to biodiversity vary among taxa
Habitat and biodiversity differences between matched pairs of organic and non-organic farms containing cereal crops in lowland England were assessed by a large-scale study of plants, invertebrates, birds and bats. Habitat extent, composition and management on organic farms was likely to favour higher levels of biodiversity and indeed organic farms tended to support higher numbers of species and overall abundance across most taxa. However, the magnitude of the response varied; plants showed larger and more consistent responses than other taxa. Variation in response across taxa may be partly a consequence of the small size and isolated context of many organic farms. Extension of organic farming could contribute to the restoration of biodiversity in agricultural landscapes