Naoko Iino

Satellite analysis and mesoscale behaviour of volcanic plumes and gas from Miyakejima, Japan

Miyakejima plumes of ash-rich and vapour-rich clouds were detected well by the NOAA/AVHRR data, and the height of eruption cloud on 29 August 2000 was estimated reasonably using the brightness temperature at 11 µm of NOAA/AVHRR and the upper air data taking into account the effect of ash emissivity. We found two different mechanisms which bring the high concentration SO2 to the mainland of Japan: convective daytime mixing brings gas down to the surface, after advection from Miyakejima in the upper air by winds associated with high pressure system; and the volcanic gas descends to the island surface in strong winds associated with stationary fronts and low pressure systems.

Temporal behaviour of Asian dust aerosols observed in 2001 using meteorological satellite data

The advection and dispersion of Asian dust events from China and Mongolia to the Pacific Ocean around Japan in the spring of 2001 were investigated using meteorological satellite data, NOAA/AVHRR and GMS-5/VISSR. Aerosol Vapour Index (AVI) images, taking the brightness temperature difference between 11 and 12 _m, are very effective in monitoring the Asian dust phenomenon in the east Asian region, because of their capacity for night-time detection. Time-series GMS AVI images, at three hourly intervals, are useful in making clear the dynamic behaviour of Asian dust. The satellite images are well reproduced by the online dust tracer model, CFORS, coupled with a regional-scale meteorological model.

Satellite Analysis of Volcanic Clouds and Transport of Acidic Substances from Mt. Aso and Mt. Sakurajima

The satellite images of volcanic clouds in Kyushu, Japan during September–November 1989 were studied in connection with the mountain site measurement of atmospheric qualities at Unzen-Nodake and the SO2 concentration data at Aso Volcano Museum. The images strongly indicate that many high concentration events of SO2 were the results of the long-range transport of volcanic gas from Mt. Aso and Mt. Sakurajima to these stations. Brief comments on the 2000 eruption of Miyake-jima volcano are added.

Effect of Pipe-Diameter Ratio on Heat Transfer and Flow Characteristics of Impinging Jet from Coaxial Circular Pipe

The impinging jet is widely used in the industrial field, as high heat transfer characteristics are obtained in the vicinity of a stagnation point on the object surface. In this paper, the heat transfer characteristics on the impinging wall after being blown off through a coaxial circular pipe were examined by changing the pipe-diameter ratio and the velocity ratio. As a result, the optimum values of the pipe-diameter ratio and the velocity ratio were found in the given conditions. The influence of the pipe-diameter ratio and the velocity ratio on the flow structure was clarified by the flow visualization.

Study on Particle Transport Characteristics of Doublet Type Suction Nozzle

In the pneumatic transportation, it was proposed by the authors that the effective and stable feeding of the particles can be attained by mounting the injection flow at the center of the suction nozzle. In this paper, we examined the influence of pipe diameter ratio on the nozzle performance. As a result, it was found that the optimum pipe diameter ratio exists. The various particles movement from different pipe diameter ratio was clarified by the flow visualization nearthe suction nozzle.

Study on Hydraulic Transport Characteristic by Discharging Plates

In the hydraulic transportation of lquid-solid flow in the conduit, to transport the particles that had piled up, the discharging plates were proposed by the author. In this paper, the installation interval of the plates was changed and the flow of the particles was examined by the flow visualization. As a result, it was found that the optimum installation interval of the plates exists, a downward jet flow influences the transportation of the particles when the interval of the plates is too wide and the jet flow in the direction of the flow influences when it is too narrow.

Thermal Fluid Flow Transport Phenomenon Over Vertical Slot-Perforated Flat Fins With Heat Sink in Natural Convection Environment

A theoretical study is performed to investigate unsteady thermal and fluid flow transport phenomena over vertical slot-perforated flat fins with heat sink, which are placed in a natural convection environment. Emphasis is placed on the effects of Rayleigh number and fin pitch on heat transfer performance and velocity and thermal fields. It is found from the study that (i) in the high Rayleigh number region, the alternating changes in the fluid flow take place for larger fin pitch, (ii) the alternating flow in the space area between two fins is mutually interacted by the corresponding one from the adjacent in-line plate fines, resulting in an amplification of heat transfer performance, and (iii) heat-transfer performance is intensified with an increase in the fin pitch, whose trend becomes larger in the higher Rayleigh number region considered here.Copyright

Visualization of Timewise Luminosity Fluctuation of Jet Diffusion Flames

Free jet diffusion flame photographs were taken by high-speed video camera. Propane was used as fuel. Flame images are digitized into 24-bit full color images by using commercial software. The digital color image is decomposed into 8-bit images of the Red, Green and Blue components and moreover each component is converted into decimal ASCII data by means of our program. In this study, the Red component luminosity fluctuation is investigated for five different fuel exit velocities. The ASCII data of 3000 frames are stored into Microsoft Excel and the time-averaged value and fluctuation intensity of luminosity are calculated by our program based on the Visual Basic Applications Edition (VBA) in Excel. These results are recomposed into 8-bit BMP images and visualized as the density slicing pseudo color images.