On 5:46Am, January 17, 1995, devastating earthquake with magnitude 7.2 hit western Japan. This earthquake was finally named “Hanshin-Awaji earthquake disaster”, and lost over 5, 500 people. Were we able to predict this earthquake? We introduce the method of earthquake prediction by monitoring electro magnetic phenomena, especially telluric current measurements.

抄録全体を表示

In order to elucidate the physical processes of the formation of fire whirl, a series of laboratory experiments on three dimentional temperature profile of crib fire plume in cross wind were performed. From the experimental result, it became evident that a fire in cross wind produces a pair of vortex-like circulation in the downstream side of fire plume. In rare occasions, fire whirls were observed in the series of experiment of multiple fires at the central or leeward part of multiple fires under weak wind.

抄録全体を表示

遺跡で検出された地震の痕跡を研究する「地震考古学」によって多くの成果が得られつつある.特に, 液状化現象については, 液状化した地層・地割れ内を上昇しつつある噴砂・地面に広がった噴砂を一連のシリーズとして観察できる.又, 過玄の地震の時期が把握できる利点を生かして, 南海地震や東海地震の周期性を把握することができた.

抄録全体を表示

The effect of liquid viscosity on the liquid-lump velocities was experimentally investigated for vertical-upward co-current flow of air and liquid in a 19.2mm ID cylindrical pipe. Water and glycerol solutions were used as working fluids to change the kinematic viscosity of liquid phase from 1.0×10^-6 to 15.5×10^-6m²/s. Flow regimes considered were slug flow, huge wave flow and annular flow. The liquid-lump velocities are discussed paying attention to the long-life liquid lump.The liquid-lumps were discriminated based on the time-spatial characteristic map of gas-liquid interfaces, which was drawn by using the mean liquid holdup signals detected by 70 pairs of holdup sensors arranged axially with a spacing of 15mm over the length of 1.035m. Velocities of this liquid lump were determined by the two arbitrary adjacent liquid holdup signals out of 70 ones. It is elucidated that the liquid vicosity has strong effects on the passing frequencies, the mean velocity and its standard deviations of the long-life liquid lumps. Furthermore, based on the characteristics of these values the effect of liquid viscosity upon the transition of flow regimes is discussed.

抄録全体を表示

Interfacial shear stress and liquid film thickness are important for the estimation of deposition and entrainment rates which are used in three-fluid model. An analytical model was developed to estimate the interfacial shear stress and liquid film thickness in the annular-mist flow. This model was used to verify the applicability of the present correlations of the interfacial and wall friction factors and drag coefficient which are used to estimate the water film thickness in annular mist flow. As the results, for the annular-mist flow in very high superficial gas velocity condition, the analytical results of the interfacial friction factor reasonably agreed with the Wallis' correlation for the interfacial friction factor which was developed purely based on the experimental data. And the calculated results of wall friction factor agreed with the equation for the laminar flow. This reason is supposed that the liquid film thickness is very thin less than transition region in the annular-mist flow under high superficial gas velocity. Furthermore, it was indicated that Kataoka's correlation for droplet diameter is applicable for the prediction of drag force.

抄録全体を表示