[en] It is important to establish an accurate heat measurement system to confirm the excess heat from the cold fusion phenomenon. During plasma electrolysis, an accurate heat measurement is especially difficult, because the input power is large and it causes significant evaporation of electrolyte and heat loss to the environment from the body of the electrolytic cell. In this study, a flow calorimetry system has been developed for accurate measurement. The energy balance of plasma electrolysis was measured at 100-102%, and the current efficiency were from 115 to 122% during the plasma electrolysis in 0.3 mol/dm³ Na₂CO₃ light water solution. Clear excess output energy has not been observed. Excess gases of 15-22% generation beyond Faraday's law was confirmed. The excess gas generation might be due to a plasma reaction. (author)

[en] Rare earth ternary borides, RRh₃B _x (R = La, Gd, Lu and Sc) have been synthesized by arc melting method. Borides RRh₃B _x (R = La, Gd, Lu and Sc) have perovskite-type cubic structure: space group Pm3m; Z = 1. The lattice parameters a of the stoichiometric RRh₃B for R = La, Gd, Lu and Sc are 0.4251(1), 0.4183(1), 0.4126(1) and 0.4080(1) nm, respectively. LaRh₃B _x does not have boron-nonstoichiometry as x = 0. In GdRh₃B _x and LuRh₃B _x, boron- nonstoichiometry ranges between 0.55 ≤ x ≤ 1 and 0.30 ≤ x ≤ 1, respectively. The boron-nonstoichiometry range is the widest, 0 ≤ x ≤ 1, for R = Sc. Boron-nonstoichiometry increases with decreasing atomic radius of R. The microhardness of the stoichiometric RRh₃B for R = La, Gd, Lu and Sc is 4.2 ± 0.1, 6.8 ± 0.1, 7.7 ± 0.5 and 9.9 ± 0.1 GPa, respectively. As a result, microhardness increases with decreasing atomic size of R in RRh₃B; R is positioned at the eight corners of the cube in the perovskite-type structure. Thus, hardness is strongly dependent on R element. The hardness changes almost linearly with boron concentration x for R = Gd and Lu in RRh₃B _x, while no linear dependency is found for R = Sc. Ab initio calculations have been performed to obtain the equilibrium lattice constants and the bulk moduli. The calculated lattice constants are in excellent agreement with experimental results

[en] Perovskite-type RRh₃B and RRh₃C (R = Y, Sc) form a continuous solid solution, RRh₃B _xC_1-x, in the range of 0 ≤ x ≤ 1 with cubic structure (space group: Pm3m, Z = 1). The values of the microhardness of YRh₃B _xC_1-x for x = 0, 0.25, 0.50, 0.75 and 1.00 are investigated as 4.4 ± 0.1, 4.9 ± 0.1, 5.5 ± 0.2, 6.4 ± 0.2 and 7.5 ± 0.15 GPa, respectively. On the other hand, the values of the microhardness of ScRh₃B _xC_1-x for x = 0, 0.25, 0.50, 0.75 and 1.00 are 4.5 ± 0.2, 6.1 ± 0.2, 7.4 ± 0.2, 8.9 ± 0.2 and 9.6 ± 0.1 GPa, respectively. Thus, the microhardness of RRh₃B _xC_1-x continuously becomes larger with increasing boron content. The oxidation onset temperatures of YRh₃B _xC_1-x for x 0, 0.25, 0.50, 0.75 and 1.00 are 604, 631, 655, 687 and 978 K, respectively. On the other hand, the oxidation onset temperatures of ScRh₃B _xC_1-x for x = 0, 0.25, 0.50, 0.75 and 1.00 are 674, 675, 695, 725 and 753 K, respectively. Thermogravimetric analysis of the phase indicates that the oxidation onset temperature also increases with boron content. Thus, it appears that both mechanical strength and chemical stability of the RRh₃B _xC_1-x phase essentially depend on its boron content. Ab initio calculations have been performed to obtain the equilibrium lattice constants and the bulk moduli. The calculated lattice constants are in excellent agreement with experimental results

[en] We report synthesis of perovskite-type boride CeRh₃B _x using the arc melting method. The samples are characterized by powder X-ray diffraction which shows that the crystal structure of CeRh₃B _x belongs to the cubic system (space group: Pm3m) in the range of 0 < x ≤ 1. Furthermore, CeRh₃ (x = 0) has the ordered AuCu₃-type structure (space group: Pm3m). As a result, CeRh₃B _x exists in a wide range of nonstoichiometric boron concentration 0 ≤ x ≤ 1 with the space group Pm3m. The lattice parameter, a, changes almost linearly with x, varying from 0.4015(1) nm (x = 0) to 0.4180(1) nm (x = 1.0). The micro-Vickers hardness of the CeRh₃B _x for x = 0 (0 at.%B), 0.210 (5 at.%B), 0.444 (10 at.%B), 0.706 (15 at.%B) and 1.0 (20 at.%B) are 2.0 ± 0.1, 4.3 ± 0.2, 1.8 ± 0.2, 5.5 ± 0.1 and 6.5 ± 0.2 GPa, respectively. Thermo-gravimetric analysis was done to study the oxidation resistance of the samples in air. It reveals that oxidation begins at 502 and 513 K for x = 0 and 1.0, respectively. A mixed phase of CeO₂ + Rh is identified as an oxidized product for all samples