An in situ technique for monitoring of contaminant transport was developed in this study. The experimental results showed that three resistivity cones which are equipped to measure pore water pressure can be used to determine the hydraulic gradient, flow velocity and direction of the groundwater and permeability. The technique proposed can monitor the in-situ contaminant plume in the soil.

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Effects of a jet perturbation on mixing performance of an air-jet array were investigated experimentally. The jet array consists of three same-sized parallel jets, and the mass flow rate of the central jet is perturbed in a pulsatile or a sinusoidal cycle with the frequency, fr = 0, 1 or 2Hz. The aligned jets issued simultaneously without the jet perturbation (fr = 0Hz) shows good mixing performance in comparison with the jet array of three arithmetically-superimposed single jets. The flow condition with the jet perturbation (fr = 1 or 2Hz), on the other hand, is alternately changed, laminar or turbulent, in one cycle of the central jet perturbation. The time-averaged velocity profiles of the jet array obtained under certain perturbed conditions demonstrate an adverse change of the mixing performance at the locations near the nozzle and far downstream. Phase-averaged velocity profiles were thoroughly examined in order to understand such a mixing mechanism of the multiple jet flow.

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This paper describes the measurement of particle behavior inside a spouted bed by use of the Nuclear Magnetic Resonance Imaging (NMR Imaging or MRI). The tagging method and the phase method, which are the velocity measurement technique of MRI, are employed to measure the particle velocity distribution in a cylindrical spouted bed. The deformation of the particle layer is clearly visualized by the tagging method. The radial distribution of the vertical component of the particle velocity is obtained by the phase method. A discrete particle simulation is also performed.

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In recent years, many researchers study on characteristic concentrations of particles in turbulent flows. However, it is difficult to observe experimentally interactions between the particles and turbulent vortices because of strong non-linearity of turbulence. In the present study, we focus on the elementary step of an interaction between single vortex tube and a solid particle in a solid-liquid two-phase flow. Burgers vortex is chosen as single vortex tube. Burgers vortex is the simplest model of turbulence.

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The motion of particles in fluid flow in a jig separator was investigated numerically and three-dimensional flow in the jig was calculated by the SIMPLE algorithm. The motion of particles was expressed by the BBO-type equation. The contact forces among particles were calculated by a discrete element method (DEM) extended to particles with size distributions. The results of simulation showed that two types of spherical particles with a difference in density of 10 kg/m³ but the same diameters could be classified (separated). In addition, particles with the same settling velocities and different diameters could also be classified (separated). To analyze the motion of particles in the jig, we derived an equation for the response time of the particle that included added mass, gravity, and drag forces.

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The effects of surfactant additives on the pressure drop and the gas-liquid interfacial structure are experimentally investigated in horizontal two-phase flow. The surfactant used in the experiment is n-Hexadecyltrimethylammonium Chloride mixed with a counter-ion sodium salicylate, and is called CTAC hereafter. Simultaneous measurements of liquid holdup and differential pressures are conducted for two test tubes with inner diameters of 13.5mm and 5.0mm. The slug flow regime is affected by the addition of CTAC. The CTAC acts as a foaming agent, and many fine bubbles are suspended in the liquid phase, which leads to the reduction in the average liquid holdup for liquid slug region. The intermittent flow with CTAC additive is called "foam-slug flow" in the present study. The drag reduction is observed in the foam-slug flow regime, and is achieved up to 30%. The drag reduction range is correlated with friction velocity, and the upper limit of friction velocity for drag reduction range is found to be 0.1m/s in both test tubes. In annular flow, an increase in frictional pressure gradient is observed. This is due to the increase in wall shear stress caused by the decrease in the liquid holdup.

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The floating system which can carry the material by non-contact has a problem that the transported materials vibrate and contact with the floating device. In this report, we observe concerning the change of the pressure distribution which occurs due to the movement of the material using the belt device that simulated the moving material and which has the static pressure tap. As a result, we show that the influence to the pressure distribution with the movement of the conveying material is larger than effect caused by simple shearing stress.

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A device was proposed to separate sponge balls from water, used in the cleaning system of heat exchangers. This experimental study was conducted to investigate the operational behavior of the centrifugal separator, aiming at improving its efficiency. The circulation behavior of a single particle (simulating the sponge ball) in the rotating flow generated inside the transparent scale-down model of the centrifugal separator was examined. It was observed that the tendency of the particle moving away from the circulation center in radial direction became stronger with increasing flow rate. Furthermore, the separation efficiency was found to depend strongly on the ratio of the flow rate conveying particles to the inlet flow rate. This dependence became less significant with the increase of the inlet flow rate.

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The flow through an abrupt expansion pipe has a large annular vortex region just after the expansion. The negative pressure in this region causes a large flow resistance, drag. Some flow control is needed to reduce the flow resistance. In this study, the reduction of the flow resistance by mounting a small ring shaped obstacle on the downstream pipe wall is newly proposed and examined. The backward flow in the vortex region was decreased by mounting the obstacle. The optimum combination of height and location of obstacle is h/H = 0.8 and L/H = 2.07 (h: height of obstacle, L: distance between obstacle and expansion, H: step height of expansion part), respectively. In this case, the flow resistance is reduced by 26% than a normal abrupt expansion pipe, and it is nearly equivalent to the 30 degree diffuser. This is a simpler method than using diffuser, particularly for a large scale pipe or duct system.

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This study deals with a sensing method of gas-liquid twophase flow in a horizontal pipe on the basis of statistical processing of differential pressure fluctuations. The experiment was carried out using nitrogen gas and water as working fluids. The flow pattern and void fraction and the velocity of gas phase were measured by PDF and cross-correlation of differential pressure fluctuations, respectively. The velocity of liquid phase, average void fraction, and flow quality were derived using a conservation law. The results suggest that the method is feasible for increasing the efficiency of an air conditioner.

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High performance Mg based hybrid five-layered composite laminates were fabricated by means of sandwiching the AZ31 Mg foils with the Carbon/PEEK prepregs, in which the nanoparticles SiO2 were uniformly spreaded at the interfaces, through hot press. The basic mechanical properties of the cross-ply hybrid laminates were obtained by tensile tests, and they were found in good agreement with the prediction by the rule of mixture. Then, the response due to constant stress amplitude tension-tension (T-T) cyclic loading at elevated temperature up to 106 cycles was investigated.The received S-N curves, when normalized by their corresponding ultimate strength, were found very close to each other. That strongly hints the higher resistance to fatigue of cross-ply hybrid laminates at higher temperature is accomplished.

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The effect of low energy laser peening (LP) without coating has been studied on metallic materials. A highly penetrable neutron beam was used to evaluate the overall distribution of residual stress. Compression in the top surface and its thermal stability were non-destructively confirmed through precise experiments with synchrotron radiation. The three-dimensional (3D) image of fatigue cracks was clearly reconstructed by micro tomography (μCT) with phase contrast technique. It was shown that the growth of the cracks was retarded for the laser-peened materials.

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The in-plane tensile stress-strain properties of two kinds of commercial paper and a kind of paperboard were determined in a compact testing machine equipped with an optical extensometer. Copy paper, sack paper made from unbleached kraft pulp and paperboard were tested at about 25°C and two different relative humidity of 25% and 55%. A dumbbell or dog-bone type specimen specified in the JIS Z 2201for sheet materials was used in the tension tests, instead of a constant-width strip specimen specified in the ASTM D828-97. Tension specimens were cut in three different orientations from each type of paper and paperboard on a paper cutter, following a steel plate. The thickness of paper and paperboard was carefully measured with a high-precision digital micrometer under a constant pressure. The tensile properties were shown to vary greatly, depending on the specimen shape and size, test direction, ambient relative humidity and strain rate. The Ramberg-Osgood equation was used to model the nonlinear stress-strain behavior.

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Phase-shifting digital holography is a new method to measure the displacement distribution on the surface of an object. In this paper, to miniaturize the equipment for practical use, we propose a calibration method with reference plane. The reference plane is installed on the piezo stage which is movable in three axes directions with very small amount. Deformation and strain measurement using spherical wave can be realized with this calibration method. The result for the deformation measurement using this method was shown.

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For the fabrication of Micro Electro-Mechanical System (MEMS), film fabrication process combined with photolithography is thought to be one of the fundamental techniques. However, the physical properties of films and membranes strongly depend on their processing routes. For designing MEMS as engineering products, the control of physical properties such as the coefficient of thermal expansion (CTE) and hardness are important. However the CTE measurement of thin films is very difficult because the magnitude of displacement to be measured is about 1⁄10000 of the thickness of the specimen, i.e., of the order of nano-meter for specimens with micron-meter thickness. In this study the measurement of CTE of several ten micron meter-thick metal thin film based on an optical interference was attempted using a Laser Scanning Confocal Microscope (LSCM). The specimen was set between two alumina single crystal plates as optical flats. He-Ne laser is reflected from the bottom surface of the upper optical flat (which is transparent) and the top surface of the lower optical flat, and these two rays interfere either constructively or destructively, resulting in the formation of interference fringes. It was shown that by counting the number of fringes observed using LSCM, the expansion of a specimen as thin as a few-tenth micron meter can be detected.

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A method was developed for determining the directions of the principal-stresses over an entire model from color photoelastic fringes obtained in a semicircular polariscope. The polariscope was composed of a circular polarizer and an ordinary liner polarizer. A model was illuminated with circularly polarized light and the light transmitted from the model was analyzed with only the rotation of analyzer so that phase-stepped color photoelastic fringes were obtained and the map of the principal-stress directions was later deduced from them. The effectiveness of the method was investigated with color photoelastic fringes of a circular disk under diametric compression. Results showed that the method was effective to determine the principal-stress directions with reasonable accuracy.

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In the steelmaking processes such as the desulphurization process, it's requested to disperse low density particles in the reaction vessels quickly and uniformly. In mechanical agitation, when the impeller is placed at an offset position, an inclined vortex is generated under some specific conditions and it increases the agitation efficiency significantly. In the present study, we have investigated the effect of low density particles on the inclined-vortex formation under mechanical offset agitation. As the number of low density particles on the bath surface increases, the vortex formation becomes difficult. Empirical equations are proposed for the vortex initiation time and the vortex arrival time to the impeller.

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A water model is studied to simulate physical phenomena in the Lintz-Donawitz (LD) steel converter. The depression in the liquid, due to the impinging gas jet, is measured by means of a video camera. Image processing tools together with a non-linear mathematical model based on the physics of the liquid-gas system are used to describe the cavity profile. Under the assumption that the cavity profile is stationary, a quantification of the uncertainty of the depth and diameter estimates is given. The variance of the estimates is experimentally shown to decrease by 50% under the assumption that the cavity depth and diameter oscillations can be described as a sum of a small number of sine waves.

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In the iron and steelmaking industries efficient agitation of molten metal and slag is of essential importance. The main agitation methods currently employed can be classified into three types; gas injection, electromagnetic stirring, and mechanical agitation using an impellor. Injection gases such as Ar are expensive and yet the agitation efficiency is not necessarily high in the gas injection agitation. The electromagnetic stirring processes currently used are too expensive and their use is very limited to special cases such as the continuous casting process. In addition, the efficiency of the mechanical agitation is not so high. Therefore, alternative, cheap and effective mixing methods are required. As one of candidates for the methods, a novel agitation method using a swirl motion of a bottom blown liquid jet is proposed in this study. The characteristics of a swirling liquid jet in a bath with low-density particles on its surface are experimentally investigated. This method is applicable also to wastewater and sludge treatments.

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A cylindrical bath is strongly agitated by a swirl motion of a bubbling jet. This swirl motion is useful for wastewater treatment. Wastewater sometimes contains sludge in it. So far, the effect of sludge on the swirl motion has not been investigated. Air, silicone oil, and spherical particles are used in this study as the models for a mixture of ozone and air, wastewater, and sludge, respectively. The density of the particles is lower than that of silicone oil, and accordingly, they initially float on the bath surface. In the presence of the swirl motion, they are carried deep into the bath due to strong mixing ability of the swirl motion. The occurrence condition and basic characteristics of the swirl motion are investigated. An apparent kinematic viscosity is introduced for correlating the period, amplitude, starting time, and the damping time of the swirl motion. Empirical equations are proposed for these quantities.

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The purpose of the present study is to develop a simple removal method of dioxins⁄furans (dioxins) from a combustion gas at low cost. Removal method of suspended matters in gas (as a cold model) and dioxins in exhaust gas (as a hot model) has been investigated by gas injection into water; the mechanism is that the suspended matters in the gas gather on gas-liquid interface.In the cold model, the removal ratio of fine particles (R_P) by injecting gas into water was correlated well by the following equation: R_P (%) = 100 X { 1-exp(-0.8•S_S•t_C )}, where Ss (1⁄cm) designates a specific surface area of bubbles, and t_C (s) a residence time of bubbles in water.In the hot model under combustion experiments of poly vinyl chloride, the removal ratio of dioxins (R_D) by injecting the exhaust gas into water was estimated as: R_D (%)=100X{ 1-exp(-0.8•S_S•t_C•C_D0^0.07)}, where C_D0 (ng⁄cm³(s.t.p.)) designates dioxin’s concentration in the exhaust gas before injection into water.

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A new type of electrochemical random signal analysis technique was applied to galvanic corrosion of anodic oxide films formed on 6061-T6 aluminum alloy in NaCl containing 0.5 kmol⁄m³ H₃BO₄ ⁄ 0.05 kmol⁄m³ Na₂B₄O₇ solutions. The effect of the anodic oxide film structure on the galvanic corrosion resistance was also examined. During incubation (before localized corrosion started), both current and potential change slightly from the initial value. The incubation period of porous type anodic oxide specimens is longer than that of barrier type anodic oxide specimens. During localized corrosion, the current and potential changing with fluctuations, and the potential and the current fluctuations show good correlation. The slope of the PSD of both potential spectra of anodized specimens is about minus one ( -1 ), after the localized corrosion has started. This technique allows observation of electrochemical impedance changes during localized corrosion.

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The reactor vessel involving batch operations has been widely used in the ferrous and non-ferrous production processes. In their processes, more than one liquid phase are usually contained in the vessel, and it is desirable to discharge each phase separately as fast as possible. In separating co-existing two kinds of liquids, the liquid of the bottom layer is usually discharged through a nozzle located at the bottom of vessel. However, as lowering the liquid-level by discharging the liquid, a swirling flow generates, and the rate of discharging the liquid decreases. Moreover, the liquid of the upper layer is caught by the swirling flow, and the upper liquid begins to discharge along with the bottom one. In the present study, the efficient discharge method of liquid in a cylindrical vessel type reactor by the prevention of a swirling flow generation was examined through water-model experiments. It is confirmed that to lengthen the nozzle shortens the water discharging time if the generation of air-core is prevented. Then, the larger the initial angular velocity of water surface and the shorter the nozzle length, the higher the water level at which air-core arises. The effect of the initial angular velocity is much larger than that of the nozzle length. The prevention of the generation of the air-core is one of essential factors in separating coexisting two liquid phases perfectly at high speed. The gas injection is effective for preventing the generation of air-core.

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A newly developed bottom gas blowing method consisted of bottom nozzle with double or triple annular tubes was presented to improve the flexibility of the bottom gas flow rate and the bottom blowing stability. Hydrocarbon blowing through the inner tube of the bottom nozzle realized stable stirring without over cooling of the nozzle. By using bottom gas blowing method mentioned above, iron oxidation was suppressed in the last stage of the blowing and (T.Fe) content which meant iron content existed as iron oxide in the slag was decreased.

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