Reactor coolant pump performance under two-phase flow condition has been recognized to be an important area of concern in nuclear reactor safety analysis. Nonuniform void distribution at the inlet of such a pump due to the suction pipe bend can have a significant effect on the impeller blade characteristics.From such circumstances, this paper aims firstly to propose an analytical method of solution for the two dimensional thin hydrofoil placed in liquid-gas two-phase flow assumed to be incompressible and homogeneous, and secondly to clarify the effect of void fraction distribution, which exponentially changes in the direction normal to free stream, on the hydrodynamic characteristics of hydrofoil.

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Diopside (CaO·MgO·2SiO₂) was sintered at 1300°C for 2hours.It was soaked in a simulated body fluid at 36.5°C.Three days later diopside formed Hydroxyapatite all over the surface.
Diopside implanted in rabbits came in close contact with the newly grown bone. XMA spectral diagrams show a change of composition across the junction from the diopside to the newly grown one.High-resolution photograph taken on the junction between the diopside and the surrounding crystal.Crystal lattice in the diopside and surrounding crystal were continuous and arranged in one direction.

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The effect of Bi2O3 addition on the initial permeability of (MnZn) Fe2O4 has been studied with reference to the microstructure.It is found that the initial permeability of the ferrtite is increased, but it becomes more sensitive to the stress as Bi₂O₃ is added.
Bi₂O₃ addition decreased the difference in oxygen content between the inner and outer regions of the bulkmaterial.This decrease, in oxygen variation might contribute to the increase in permeability.
A new MnZn ferrite has been developed with a high initial permeabillity of 23000 at 10kHz through Bi₂O₃ addition and the use of an improved mixing process.

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The effective thermal conductivity of the clothing materials in which heat flows accompany with mass transfer has been studied.The condition of this measurement may be more similar to practical use of the cloths.The experimental apparatus based upon the steady state comparison method is slightly modified in this study.The water tank is put on the heater and heat is flowed through the sample cloths upward from the heater that is placed at the bottom of the apparatus.The ordinary clothing materials used widely are selected as the sample.
If the heater and the room temperature are kept constant, vapourizing rate η is scarcely independent of the number and the kind of cloths.The η, however, depends on the temperature difference between the heater and room temperature and relative humidity of the room.On the other hand, the temperature difference between upper and bottom surface of sample is nealy proportional to the number of cloths.Therefore, the effective thermal conductivity coexisting with heat conduction and mass diffusion may be evaluated by obtaining the sum of the thermal conductivity in the case that heat or mass transfers alone through the cloths.

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Graft copolymers of Chitosan-Bromo 2-(trimethylammono) ethyl acrylate were prepared by the reactions of chitosan with brom 2-(trimethylammono) ethyl acrylate. The flocculating ability for 5% kaolin suspension was invesigated in relation to the structure of graft copolymers by measuring the sedimentation rate.the residual turbidity, and the sedimentation volume.
The results obtained were as follows.1) For every copolymer, the optimum flocculating ability was obtained in the concentration of nearly 10 ppm and an isoelectric point was observed in the same copolymer dosage.2) Suitable graft chain length (F₂) for the flocculating ability was about 0.2∼0.5.3) An isoelectric point was found in the vicinity of pH 5 and the optimum flocculating ability was observed in the same pH. 4) Suitable pH for good flocculating action was observed in the pH range of 2∼10.5) Copolymers obtained was more effective for the flocculation than typical commercial fiocculants such as Sumi fioc FC, PAS-A, and Himoloc Neo 600.

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The effects of charging temperature and time on the embrittlement of cathodically hydrogen-charged specimens were investigated by tensile test and scanning electron microscopic studies on Alloy 690 single crystals with ‹100› tensile axis. Many cracks on the specimen surface were observed along {100} traces. Crack depth does not exceed several ten microns and corresponds to the thickness of hydride formed during the charging.Fracture strength was decreased after passing through maximum and fracture elongation was gradually decreased with the incerases in charging time.The crystallographic plane of fractured surface always consists of {100} plane.The diffusion coefficient (D₁) of hydrogen atoms in the grain is less than that at grain bundary.Activation energy for the diffusion obtained from the temperature dependence of D₁ was estimated to be 7.3 kcal/mol.

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A pulse train analysis is reported here from the viewpoint of both a hardware and a software.In hardware part, an interface board is specifically designed which can administer the height and the timing of the pulses of a pulse train.The front-end of the hardware system is a Wilkinson-type ADC. The crude data taken in by the hardware are pulse height and arrival time of respective pulses.The software part reconstructs the data into pulse height distribution, time interval distribution, count rate representation, direct representation of pulses along the time elapsed, frequency distribution f (n) of pulse count n, and such statistical moments as μ, σ, S, K of f (n). Statistical tests can be practiced as well. The system is actually applied to the anticipation of magnet relay breakdown.

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The interatomic potential derivatives related to higher-order force constants are formulated in the microscopic electronic theory.The convergence of the numerical integral in calculating the interatomic potential derivatives becomes worse as the degree of the differentiation increases.The difficulty of the convergence for the fourth derivative of the interatomic potential is overcome using the asymptotic form of the integral function.Numerical calculations are performed for practical material Al with low density and for alkali metal K with high density and with anharmonic characteristics.The accuracy of the interatomic potential derivatives obtained should be confirmed by considering non-integral term in addition to integral term.The interatomic potential derivatives as function of the atomic distance and under compression are calculated in connection with the convergence of the integral.The convergence of the numerical integral for the third and fourth derivatives of the interatomic potential related to the anharmonic property is established by increasing the upper limit, and the overall value X_m=10 as the upper limit of the non-dimensional wave number is proposed.

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In this study, we ultra structurally evaluated the interface between granular diopside and diopside-induced hydroxyapatite (HAp), and presented a growth mechanism of HAp at the surface of diopside.Specimens were prepared in the following two experiments.
1) Granular diopside immersed in the simulated body fluid for 5 days.
2) Granular diopside implanted into the rabbit bone cavity and left for 1 month.
In the first step, epitaxial crystal growth of octacalcium phosphate (OCP) occurs in the diopside surface layer.The epitaxial relationship of OCP on diopside are as follows,
(001) _di// (010) _ocp
[110] _di, // [100] _ocp
The lattice mismatch between the c-axis of OCP and [110] of diopside is 3.7% whereas between the a-axis of OCP and three times of [110] period of diopside is 0.05%.
In second step, OCP changed to HAp by topotactic phase transition. The topotactic relationship between OCP and HAp are as follows,
a_ocp=2a HAp
b_ocp=b_HAp
c_ocp=c_HAp
In the early period, HAp crystals observed were platelet-shaped.It is influecned considerably by the shape of OCP. HAp grows into a hexagonal prism shape.

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Amorphous silicon (a-Si) solar cells, which have p-i-n structures, are reviewed with special reference to cell structures and element (φ) additition to a-Si φ: H. The evolution of the structure from singlejunction to multijunction makes tremendous progress in accomplishing higher photovoltaic energy conversion. The high conductivity and transparency of p-layer, or window layer, is of prime importance for the performance of entire solar cells.The improvement of p/i interface is significant in order to avoid recombination of engendered charge carriers migrated from i-layer.Further, hydrogen dilution shows pronounced effect on the reduction of Si dangling bonds which cause recombination.Namely, the photovoltaic efficiency and degradation by light soaking are well ameliorated by these advanced technology.The degraded solar cells contain higher ratio of-(Si-H₂)-n dihydride bonding, which is distinguished, by FTIR, from Si-H single bond observed predominantly in initial cells.The formation of dangling bond, recombination of carriers and relationship among Fermi level, band edge, and band width are also discussed. The flexible solar cells fabricated on organic resins have promising future with wide applications.

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