The hydrogen electrode reaction characteristics of thin film electrodes of Ni-based hydrogen storage alloys

Film-type electrodes of hydrogen absorbing intermetallic compound and alloys, LaNi₅, Ni_0.11 Ti_0.89, Ni_0.50 Ti_0.50 and Ni_0.76 Ti_0.24 were prepared by a flash evaporation method. The hydrogen electrode reaction characteristics of the LaNi₅ and NiTi alloy films in 1 M NaOH are very similar to each other. The reaction proceeds via the Volmer-Tafel reaction route with mixed rate-determining characteristics. The exchange current densities of the constituent steps, as well as the overall reaction, are in the range of 10^?6 A cm^?2 (true). Surface analysis by an XPS technique has shown that La or Ti on the electrode surface exists as an electrocatalytically innert oxide of La₂O₃ or TiO₂. Close similarities of these electrodes with pure Ni electrodes indicate that Ni is responsible for the electrocatalytic activity. No synergistic effect is thus noticeable.     

Heat transfer between gas fluidized beds of solid particles and the surfaces of immersed heat exchanger elements,part I

After some general remarks about fluidization, and a section on the hydrodynamic behaviour of fluidized beds, the mechanisms of heat transfer between the surfaces of heat exchanger elements and gas—solid fluidized beds are discussed in detail. A theoretical model, presented some years ago, is slightly modified and further developed to improve its applicability within a wide range of variables. The model makes use of some of the basic concepts of molecular kinetic theory as applied to solid particles in a fluidized bed. A complete derivation as well as all the parameters required to apply the model equations are given.     

Extraction of coals through dilute alkaline hydrolytic treatment at low temperature and ambient pressure

Assam and Talcher (bituminous) coals have been subjected to batch aqueous alkali treatment followed by extraction. It has been shown that alkali treatment increased extractability and reactivity of coal. Use of 1.4% aqueous sodium hydroxide was found to be capable of rendering about 40–50% coal extractable in ethylene diamine in two alkali treatments followed by extractions. Semibatch operation yielded about 26–33% extractable coal, and extraction data were found to be comparable with those obtained in batch degradation via a single alkali treatment. Of the solvents studied, polar and basic solvents were found to be the most effective.     

Lead content of small mammals at a roadside site in relation to the pathways of exposure

Concentrations of lead have been determined in three species of small mammal, Sorex araneus, Clethrionomys glareolus and Apodemus sylvaticus at roadside and control sites. The results are considered in relation to the lead content of the diet and the air, and it is concluded that the diet provides far the major pathway for lead exposure, even at the roadside site. Bone lead concentrations are found to be consistent with estimated lead exposure and metabolism.     

Direct observation of inelastic deformation and mechanochemical activation of indented quartz single crystals

In a basic study of the mechanism of mechanochemical activation of fine powdery materials, a large single crystal of quartz was stressed by loading with a diamond indenter. The stressed crystal was subsequently immersed in 1 N KOH solution at 60 °C for various periods. The microstructures of the indented region before and after immersion were observed under a scanning electron microscope, in order to examine the direct correlation between the manner and the extent of deformation and the degree of activation. Inelastic deformation was recognized by indenting under a load as low as 1 kp. As the force is related to the area of indentation, the corresponding local pressure amounts to about 10 GPa. At higher loads, very fine fragments were produced and deformed highly inelastically. This part of the material dissolved preferentially because of the enhanced reactivity. It was thus verified qualitatively that the enduring effect of mechanochemical activation is a consequence of the inelastic deformation.     

Nitrification process in a packed bed reactor with a chemically active bed

A laboratory scale submerged filter filled with crushed marble was used for the nitrification process investigation. The results obtained showed that the alkaline reactor filling material react with the hydrogen ions released during the process course which enables reactor exploitation without any pH value or alkalinity control.     

Magnetic properties of sulfate glasses doped with transition metal ions

Magnetic susceptibility measurements on ZnSO₄K₂SO₄ glasses containing high concentrations of Mn²⁺, Co²⁺ or Ni²⁺ ions suggest the presence of weak ferromagnetic interaction.     

An epidemiological study of well-water nitrates in a group of south west african/namibian infants

A study of 486 infants consuming well-water with various nitrate concentrations showed a strong correlation between actual nitrate intake and methaemoglobin levels. The regular administration of Vitamin C to infants is more important than the effects of age in lowering methaemoglobin levels. Mothers who live in high nitrate-bearing areas have increased infant wastage.     

Hydrogen and oxygen from water—III evaluation of a hybrid process

A hybrid process, which simultaneously produces mechanical power and hydrogen and oxygen from water by the use of solar energy, is presented. The performance of the process is evaluated. Realistic constraints on the efficiencies of optical and mechanical components are used. A preliminary estimate of its economics is also presented.