Irving Sheft

Current status and performance of the argonne Hycsos chemical heat pump system

Abstract The Argonne hydrogen conversion and storage system (HYCSOS), under development since 1975, is a two-hydride concept which operates as a chemical heat pump for the storage and recovery of thermal energy for heating, cooling and energy conversion. The system, designed and constructed to show the scientific feasibility of the concept and to evaluate system components and materials for use as hydrides, has been operational for several years. Hardware for the operation of the system under computer program control is complete and routines for data handling and analysis are available. Transient thermal and effectiveness measurements on the current coiled-tubing heat exchangers were made and will be compared with those for an advanced concept tubular heat exchanger with alloy-loaded aluminum foam for heat transfer enhancement. Recent developments of alloy materials and their use in chemical heat pumps will be discussed.

Metal hydrides as chemical heat pumps

The refrigeration mode of operation for a two metal hydride chemical heat pump system is described. A derivation is presented for general heat pump equations which may be applied to any pair of compounds which show a linear relation of ln P vs 1/T for their heat pump performance. The coefficient of performance of a two metal hydride refrigerator is obtained. (SPH)

Deuteron trapping in titanium

Abstract A tensimetric technique has been developed for measuring 15 keV D + trapping in Ti metal. The formation of the TiD 2 phase in the surface and near-surface regions was monitored by decoupling the θ–2θ scan of an X-ray diffractometer as well as by scanning electron microscope studies. Micron-sized ‘reaction zones’ appear to serve as nucleation centers for the TiD 2 phase. Insight into the mechanism of chemical trapping is obtained by correlating the results from the three types of measurements used in the present work.

Anhydrous hydrogen fluoride: Vapor pressure and liquid density☆

Abstract The vapor pressure of HF has been redetermined between 273 and 303°K and is represented by log10P(torr) = 1·3428 − 947·26/T + 3·0233 log10T. The calculated boiling point is 292·90° K. Using 3·753 for the association factor at 292·90°K, 1623·77 cal/20·006 g is obtained for the heat of vaporization at the boiling point. Between 273 and 296°K, the density of HF is given by d (g/ cm 3 ) = 1·77304 − 3·27036 × 10 −3 T + 1·81459 × 10 −6 T 2 .

Lattice Phonon Spectra of Aluminum Oxide Anodic Films

Techniques have been developed for obtaining reproducible lattice phonon spectra of barrier aluminum oxide anodic films. Changes in the lattice phonon spectrum as a result of 15-keV proton bombardment are interpreted in terms of the formation of Al-OH bonds. Polarization spectra of stripped and unstripped aluminum oxide films confirm the findings of Vedder and Vermilyea, particularly with respect to the origin of the 960 cm−1 band. The close similarity in the observed and calculated band shapes (using the theory of Berreman) leave little doubt that the 960 cm−1 absorption is due to a longitudinal optic mode of the aluminum oxide lattice.

Complex compounds of xenon hexafluoride with the alkali fluorides

Abstract The complex salts CsXeF 7 , RbXeF 7 , C 2 XeF 8 and Rb 2 XeF 8 have been prepared and characterized, and evidence is presented for the existence of K 2 XeF 8 and Na 2 XeF 8 . The decomposition pressures of CsXeF 7 and RbXeF 7 have been measured. The liquid density of XeF 6 has been determined over the range 50–76°, but attempts to measure the conductance of a solution of CsXeF 7 in XeF 6 have not been successful.

Anhydrous hydrogen fluoride: Raman spectrum of the liquid☆

Abstract The Raman spectrum of liquid hydrogen fluoride has been measured at a series of temperatures between −34·1°C and 49°C. Complex bands were found at displacements of 150, 400–700, 1000–1300 and 3000–3600 cm −1 . The intensity distribution within each of these bands is markedly temperature dependent. From the complexity of the temperature dependence and previously reported vapor density data, we conclude that a model involving all polymer species will be shown to be more correct than a model greatly emphasizing the hexamer.

A thermodynamic analysis of HYCSOS, a hydrogen conversion and storage system

Abstract A two metal hydride system for the storage, retrieval and conversion of thermal energy is described. The system functions—heating, cooling and power production—are discussed for solar energy applications. A thermodynamic analysis particularly of the conversion cycle is presented. It is concluded that solar concentrators providing heat transfer fluid temperatures of 140°C could give conversion efficiencies of 16.5%.

Hydroxyl formation accompanying defect center production in proton and deuteron bombarded aluminum oxide

The defect center produced in Al2O3 by energetic neutron or electron bombardment which gives rise to a 205 nm (6.03 eV) absorption band appears with two to three orders of magnitude higher intensity in proton and deuteron bombarded samples compared to either neutron, electron or heavier ion bombardments. The infrared spectra of this system is used to show that the formation of OD or OH provides an additional mechanism of defect production. (AIP)

Halides Of The Actinide Elements

Publisher Summary The binary halides of the actinide elements constitute a most important class of compounds. The actinide elements themselves are, of course, vital to all currently practical means for releasing nuclear energy, and the halides of these elements are leading protagonists in nuclear technology. As is the case for other groups of elements in the Periodic Table, the halides are particularly convenient for many kinds of scientific investigations and correlations. Much of what is now known of the electron configuration of the actinide elements, for example, has been learned by experiments with halides. A recapitulation and reassessment of the halides of the actinide elements in the light of recent developments thus becomes appropriate. The present review will be confined to the solid binary halides and principal attention will be focused on the developments, which have occurred since the subject was last reviewed. For an interesting and authoritative review of the entire subject of the actinide elements, the recent account of G. T. Seaborg can be warmly recommended.