[en] The standard free energies for formation of AlF₃, ThF₄, UF₃, UF₄, CrF₂, MnF₂ and CrF₃ were determined by emf measurements. From the emf values and Δ/sup f/ G⁰ (MgF₂) obtained from Δ/sup f/ H⁰ data by calorimetry measurements, the standard free energies of formation of the above fluorides at 600⁰C were calculated as follows: Δ/sup f/ G⁰ (AlF₃) = -306.0 +- 0.2, Δ/sup f/ G⁰ (ThF₄) = -436.6 +- 0.8, Δ/sup f/ G⁰ (UF₃) = -310.9 +- 0.8: Δ/sup f/ G⁰ (UF₄) = -394.0 +- 1.3, Δ/sup f/ G⁰ (CrF₂) = -156.4 +- 0.3, Δ/sup f/ G⁰ (MnF₂) = -175.0 +- 0.2, Δ/sup f/ G⁰ (CrF₃) = -229.1 +- 1.0 (kcal/mol). (U.S.)

[en] MgB₂ single crystals with a sharp transition width (ΔT_c∼0.3 K) were grown by the ambient-pressure synthesis. The upper and lower critical fields, H_c2 and H_c1 were evaluated from the magnetization for the applied field μ₀H≤5 T parallel to the three crystallographic directions. The coherence length ξ and the penetration depth λ for each direction were deduced from these critical fields with a little assumption for H_c1. The anisotropy ratio γ_H=ξ_c/ξ_ab was estimated to be ∼6.5 at 2.5 K and ∼2.3 near T_c (=37.6 K), and γ_λ=λ_c/λ_ab(=3.0±0.2) to be almost constant over the range 2.5 K≤T< T_c

[en] Electron spin resonance of anisotropic magnetic centers (dangling bonds) and conduction electrons in hydrogenated microcrystalline silicon (μc-Si:H) prepared by plasma-enhanced chemical vapor deposition (PECVD) has been observed at room temperature. The anisotropic g-shifts of dangling bonds in μc-Si:H are discussed in terms of tight-binding approaches and in comparison with those of dangling bonds in μc-Si:H prepared by hot-wire CVD and hydrogenated amorphous silicon (a-Si:H), P_b centers at the Si-SiO₂ interface and defects in crystalline silicon (c-Si). The spin densities of anisotropic magnetic centers and conduction electrons were measured as a function of gas-dilution ratio of SiH₄ into H₂ in mixture gas used in PECVD and are discussed

[en] Liquid metal application for nuclear power plants was initiated in the design of fast reactors using sodium or lead bismuth, and are very famous for sodium fast breeder reactor and lead bismuth fast reactor. In a course of development of FBR, Na and NaK were carefully compared and the former was chosen as the candidate coolant, followed by various Na cooled test reactors. PbBi fast reactor was put into practical use as a engine for nuclear ship, following research activities as a thermal reactor with PbBi coolant. In the nuclear fusion application, liquid metals of Li or LiPb will be used as a coolant and/or tritium breeder in comparison with water and helium gas. It is well known that in a nuclear reactor, materials are required to function as moderator and coolant. Though these functions are satisfied with separate materials, it is very reasonable to combine these functions to one materials, such as water or sodium, as is rearized by LWR or Na-FBR The economical success of these reactors depend on the selection of coolant material that works as neutron moderator at the same time. This design option resulted in a great reduction of the size of system and in an increase of the system efficiency. On the analogy of this history, fusion coolant might be consolidated in future to the material that works as the coolant and T breeder, such as Li or LiPb, and not in water or helium which need separate breeding material in addition to coolant. However, the MHD flow problem does not exist in nuclear power plants and the prospect for the solution of this problem will largely affect conclusions. The other example of liquid metal application, is the liquid metal target, represented by Li target for IFMIF and PbBi target for ADS. The technology required in IFMIF may be quite different, and may rather be nearer to those for inertia fusion power plant. (orig.)

[en] It is intended that the toroidal field (TF) coils of the nuclear fusion machine utilize noncircular field coils in view of the mechanical strength of the coil. In these machines, TF coils are quite large, moreover experience considerably large electromagnetic force. Consequently, stress analysis plays an important role in the reliability of the coil. This paper describes the finite element stress analysis, field calculation of the D shape TF coil and the test results of the model coil. 4 refs

[en] Nb-Al-N and Nb-Si-B powder compacts were prepared by spark plasma sintering, and their microstructure, mechanical properties and oxidation behavior were investigated. Adding nitrogen was easily done by blending or mechanically alloying Nb and AlN powders and then sintering them. The addition of nitrogen caused the formation of Nb₂N in all the Nb-Al-N compacts and Nb₂N and Nb₃Al₂N in compacts with high aluminum and nitrogen contents. The highest room-temperature hardness and the highest yield stress at 1,473K were observed for compacts consisting of Nb₂N and Nb₃Al₂N and those consisting of Nb₂N and Nb₂Al, respectively. Nb-Si-B compacts were prepared from elemental powders. Two or three of NbB₂, Nb₅Si₃, Nb₅Si₃B₂ and NbSi₂ phases were identified as constituent phases of Nb-Si-B compacts depending on composition unless a large amount of silicon is consumed by forming SiO₂. Contributions of NbB₂, Nb₅Si₃ and Nb₅Si₃B₂ phases to room-temperature hardness and yield stress at 1,973K were much larger than those of NbSi₂. However, the oxidation resistance of Nb-Si-B compacts increased with increasing the volume fraction of NbSi₂. The oxidation resistance of Nb₅Si₃B₂ was better than that of Nb₅Si₃, but was not as good as that of NbSi₂

[en] The world largest superconducting fusion machine LHD (Large Helical Device) is under construction in Japan, aiming at steady state operations. Its basic control system consists of UNIX computers, FDDI/Ethernet LANs, VME multiprocessors and VxWorks real-time OS. For flexible and reliable operations of the LHD machine a cooperative distributed system with more than 30 experimental equipments is controlled by the central computer and the main timing system, and is supervised by the main protective interlock system. Intelligent control systems, such as applications of fuzzy logic and neural networks, are planed to be adopted for flexible feedback controls of plasma configurations besides the classical PID control scheme. Design studies of its control system and related R and D programs with coil-plasma simulation systems are now being performed. The construction of the LHD Control Building in a new site will begin in 1995 after finishing the construction of the LHD Experimental Building, and the hardware construction of the LHD central control equipments will be started in 1996. A first plasma production by means of this control system is expected in 1997. (author)

[en] The right ventricular (RV) emptying performance in patients with congenital heart diseases was investigated by temporal Fourier analysis of multigated cardiac blood-pool studies on a pixel-by-pixel basis. In 15 normal subjects, no significant differences were detected between the mean values of phase of left ventricle (LV) and RV. In patients with ventricular septal defect (VSD), cases with minimal interventricular left-to-right (L-to-R) shunt without pulmonary hypertension (PH) showed normal phase and amplitude images, and cases with moderate or large L-to-R shunt with hyperkinetic PH showed delay of RV phase compared to LV, however, in a case of Eisenmenger type VSD, as well as in patients with primary PH, RV phase lag was not detected. In patients with mild pulmonary stenosis with intact ventricular septum, phase and amplitude images were normal. A case with moderate pulmonary artery stenosis showed mild delay of RV phase. Distinct phase lag of RV was shown in patients with tetralogy of Fallot. Evaluation of RV emptying performance by temporal Fourier analysis is highly valuable for pathophysiologic investigation of congenital heart disease

[en] Objective: To study the induction of DNA double-strand breaks (DSBs) in human osteosarcoma cells irradiated by X-ray, the DNA DSBs repair process and the tumour cell radiosensitivity. Methods: Two cell lines of human osteosarcoma, Rho0 and 143. B were used. Initial DNA damage of DSBs by X-ray irradiation was measured using clamped homogeneous electrical field (CHEF) electrophoresis. Results: X-ray-induced DNA DSBs of human osteosarcoma cells after CHEF-electrophoresis increased linearly with the irradiation dose between 0 and 50 Gy. The repair of DNA DSBs in human osteosarcoma cells increased with the post-irradiation incubation time. In contrast to 14.3B cell line at the same dose point, much more DNA DSBs were induced in Rho0 cell line after X-ray irradiation. Conclusion: CHEF pulsed-field gel electrophoresis (PEGE) is a sensitive method for the determination of radiation-induced DNA DSBs in high molecular weight DNA of human osteosarcoma cells. Radiation-induced DNA DSBs of osteosarcoma increase with the dose in a linear manner. After incubation, both Rho0 cell line and 143. B cell line can repair the DNA DSBs. Between two cell lines of human osteosarcoma, Rho0 and 143.B, Rho0 cell line is more sensitive to ionizing radiation than 143.B line

[en] We tried to construct a simple integrated tube-type pyranometer using phycoerythrin from seaweed pigment. The maximum sensitive wavehand of phycoerythrin was 550 nm - 560 nm, and this waveband was in the photosynthetically active radiation range. The acrylic tubes (outside diameter, 22 mm, length, 100 cm) were spread with white paints except for a strip 15 mm in width, and phycoerythrin was put into the acrylic tube. In the results from the outdoor measurements, the tube-type pyranometer showed a positive correlation between the transmittance of phycoerythrin (%) and the measured accumulated solar radiation (MJ n(-2)), but the slope of the linear equation was different in summer and winter. In an artificial climate room, the relationship between the transmissions of phycoerythrin and the accumulated solar radiation could be approximated by a quadratic equation at every temperature. In the measurements made outdoors, the accumulated solar radiation could be estimated using the transmittance of phycoerythrin and the mean air temperature during measurements