[en] The discharge behavior of the nickel hydroxide electrode has been investigated in 30% KOH at 25 .deg. C. Two voltage plateaus are displayed on the discharge curve of C/20. It is shown that the impedance of the nickel hydroxide electrode increases with decrease of the discharge potential. The discharge behavior of the nickel hydroxide electrode has been investigated in 30% KOH indicating the reduction of the β-NiOOH to the β-Ni(OH)₂ by proton diffusion process and hence the electronic conductivity change of the nickel hydroxide electrode. Furthermore, the γ-NiOOH, produced by prolonged oxidation of the β-NiOOH in 30% KOH, discharges at a slightly lower potential than the β-Ni(OH)₂ that could result in the life-limiting factor of several alkaline electrolyte storage batteries using the nickel hydroxide electrode as the positive plate

[en] The potential of hydrogen as an energy carrier has been widely recognized due to concerns about climate change, environmental degradation and energy security. However, the storage and transportation of hydrogen remain significant challenges. Hydrides with a perovskite crystal structure can store large amounts of hydrogen in a small volume, and they are relatively easy to produce hydrogen. Among them, the ternary perovskite hydride NaMgH₃ is distinguished by its relatively high theoretical hydrogen storage densities and reversibility of hydrogen absorption and desorption. In this study, first-principles calculations within the framework of density functional theory were employed to investigate the effect of substituting Na? by K? on the structural, electronic and hydrogen storage properties of Na_1-xK_xMgH₃ (x ≤ 0:75). The results show that the substitution of Na⁺ by K⁺ induces a slight decrease in the lattice parameters and an increase in the cell volume, and the MgH₆ octahedron becomes more distorted, which is a good indicator of destabilization of the host material, ultimately leading to a decrease in decomposition temperature from 560.1 to 489.6 K, which is beneficial for hydrogen storage applications. (author)

[en] In this chapter were studied physical-chemical properties of aluminum hydride of metals

[en] The thermal stability of complex aluminium hydrides of alkali metals was studied by means of differential thermal analysis and tensimetry methods. The three-stage scheme of thermal decomposition of tetra-hydro-potassium aluminate was elaborated.

[en] This paper presents the results of study of thermal stability, the rate of thermal decomposition and thermodynamical properties of binary hydrides of alkali metals. The initial materials - binary hydrides of lithium, sodium and potassium were obtained by thermal decomposition of tetrahydro alluminates of appropriate alkali metals. The standard thermodynamical characteristics of binary hydrides of lithium, sodium and potassium were defined. The obtained results by means of comparative calculation method allowed to determine the thermodynamical characterises of all alkali metals.

[en] Present article is devoted to kinetics of thermal decomposition of complex aluminium- and binary potassium hydrides. The process of thermal decomposition of tetrahydroaluminate of potassium (KAlH₄) was studied by means of tensimetry method with membrane zero-manometer at equilibrium conditions. It was defined that the process at studied temperature rates 470-770 K compose of three stages.

[en] Isolated bulk damage centers are produced when KDP crystals are irradiated by 1-ns 1064-nm pulses. We have tested about 100 samples and find the median threshold to be 7 J/cm² when the samples are irradiated only once at each test volume (1-on-1 tests). The median threshold increased to 11 J/cm² when the test volumes were first subjected to subthreshold laser irradiation (n-on-1 tests). We baked several crystals at temperatures from 110 to 165⁰C and remeasured their thresholds. Baking increased thresholds in some crystals, but did not change thresholds of others. The median threshold of baked crystals ranged from 8 to 10 J/cm² depending on the baking temperature. In crystals that had been baked, subthreshold irradiation produced a large change in the bulk damage threshold, and reduced the volume density of damage centers relative to the density observed in unbaked crystals. The data are summarized in the table

[en] The kinetics of thermal decomposition processes of tetra-, hexa-, hydro- aluminates and potassium hydride have been studied in the present work. The results of studies of thermal decomposition processes of complex tetra-, hexa-, hydro- aluminates and binary potassium hydride have been presented. The thermal decomposition processes which pass in temperature intervals 473-560 K have been studied as well.

[en] This paper deals with the behavior of reverse osmosis system used in attachment to electrolytic cells used in heavy water water production. The vapor produced during analysis of water contains caustic KOH in concentration nearby nearby the equilibrium value. Recovery of this caustic materials from vapor stream represents an economical and technical requirement for continuous operation. In the present study, mathematical model for lumped parameter spiral wound module was derived. The effect of temperature on variation of osmotic pressure of the solution produced by vapor condensation, permeability constant of membrane material for both solute and solvent and the viscosity of were were taken into account. The study showed that increasing of feed temperature has a negative effect on the objective function of the operation where the percent solute rejection decreased decreased dependently in almost linear relation

[en] We present the results of laser damage measurements conducted on potassium dihydrogen phosphate (KDP) and deuterated potassium dihydrogen phosphate (KD*P) crystals that were grown recently for both production and research applications by several sources. We have measured extrinsic damage thresholds that cover wavelengths from 1064 nm to 266 nm at pulse durations in the 3- to 10-ns regime. Many of the samples were extracted from boules grown specifically to yield large-area crystals, up to 32-cm square, for laser fusion applications. These crystals were the result of efforts, both by the Lawrence Livermore National Laboratory (LLNL) and commercial crystal-growth companies, to yield high-threshold KDP. In particular we have established that such crystals can reliably survive fluences exceeding 15 j/cm₂ at 355 nm and 20 j/cm² at 1064 nm when irradiated with 3-ns pulses. We present details of how bulk and surface damage to these crystals scale with pulse duration and wavelength as well as of morphological effects due to laser conditioning