It is already confirmed that Fiber-cement-stabilized soil is the best for the ground material because this soil has several features. However，in order to use this soil as cover soil for radiological contaminated soils in Fukushima Prefecture， the investigation on durability for erosion is indispensable. Therefore， the durability for erosion of fiber-cement-stabilized soil using tsunami sludge was experimentally investigated in this study. The experiment was carried out by using the submerged water jet erosion test apparatus manufactured according to Hanson et al. The critical shear stress for erosion and erodibility coefficient were measured. It was confirmed that the durability for erosion of fiber-cement-stabilized soil is much larger than the one of normal soil.
On March 11 in 2011, a very big earthquake occurred in Tohoku district in Japan. As a result, a large amount of tsunami sludge was generated and the radiation contamination due to the nuclear power plant disaster has also become a serious problem. Thus, it is necessary to decontaminate the radiation-contaminated waste and soil, and the radioactive pollutant will be stored at temporary storehouses. However, because covering with original soil or sheets deteriorate under rainfall or sunlight, it is preferable to further improve these ways. This study focused on Fiber-cement-stabilized soil method. This method is a new recycling method for high water content mud by using paper debris and cement. If the cover soil for radiation-contaminated soil can be produced from the tsunami sludge, we can make effective use of the tsunami sludge and store the radiation-contaminated soil securely. In order to investigate the durability for erosion and seepage behavior due to rainfall of the cover soil made of tsunami sludge, the outdoor test were carried out. As a result, it was cleared that the soil erosion loss almost did not occurred. Moreover, relationship between rainfall intensity and change tendency of pore water pressure was investigated.
This paper is concerned with the plant fluid mechanics. The displacement of the dandelion petal movement was measured by the optical displacement detector system. The petal movement speed was determined from the displacement measurements. The surface shape composed of petal cells in the folding and unfolding of dandelion flower head was measured with the color 3D laser scanning microscope. Non-contact measurement of surface roughness on the dandelion petal with laser acquisition of three-dimensional data was conducted over a long period of time. Surface cells showed expansion and contraction through the opening and closing of flower head. Fluid flow in petal cells with the flower head movements was discussed.
In order to produce bio-diesel fuel (BDF) effectively from triglyceride contained in coffee grounds, the solid catalyst method using calcium oxide was examined. Since commercially available calcium oxide has low catalytic activity, a method of converting the calcium oxide to calcium methoxide and/or calcium glyceroxide before esterification was tested. The method was applied to generate the BDF from unused canola oil. The produced liquid was analyzed both chemically and by the NMR, and it was revealed that the liquid was able to be called as BDF and esterification rate was about 80%. Extraction of triglyceride from waste coffee grounds was tried using hexane as a solvent, and 780 mL of triglyceride-rich oil was extracted from 8 kg of the waste coffee grounds. The oil was subjected to the BDF production using the calcium oxide and the BDF was produced at the esterification rate of about 75%. The coffee grounds after the extraction of the triglyceride-rich oil were applied to deodorants and solid fuels. The experimental results showed that the coffee grounds decreased the smell of cigarettes. Furthermore, it was also found that the coffee grounds were easily ignited and burned by adding some sawdust and wax to the coffee grounds.
In recent years, plant factories with indoor hydroponics come to attract attention with the development of low cost LED lamps. In addition, the fact of low food self-sufficiency rate in Japan makes it important to develop of plant cultivation technology for a stable food supply based on the engineering knowledge and conception. In this study, water remediation technologies utilizing the micro-bubbles and micro jet are applied to cultivate root vegetables in hydroponics. We aim to develop the automated indoor type of food production system with fully controlled environments. In this paper, we represent the results of the effect of dissolved oxygen on growth of root vegetables.
Three-dimensional measurement of displacement with Digital Image Correlation (DIC) method was investigated. A new method to measure three-dimensional displacement using a stereo camera is proposed. In the method, calibration test was made in advance and images of a stereo camera for surface of a flat plate were obtained by moving the plate in x, y and z direction from the base position. The author composed simple empirical equations to express relations between parameters for movement of images obtained with DIC and actual movement of the flat plate using the result of the calibration test. These empirical equations can be used as look-up equations (LUE) dominating directly relation between moving of images and moving of the object in three-dimension and three-dimensional displacement of the object can be calculated by solving the LUE inversely. This LUE expresses the relation between movement of images and displacement of the object and includes the effect of error of camera settings. Influence of these errors is cancelled in the measured result by this method. Measured results using this method for parallel translation and deflection of a steel beam showed that measurement of three-dimensional displacement is possible with sufficient accuracy.
For the purpose of recycling of waste glass fiber reinforced plastic(GFRP) and easing of heat island phenomenon, authors have previously proposed a greening plant that moss was planted on ceramic base made from clay and waste GFRP. In this study, the improvement of wind resistance performance of the ceramic base planted with moss was attempted by arranging indents on the surface of the ceramic base. Firstly, for the some ceramic bases which arranged indents of the dimension which differs on the surface, the flow of wind on the base surface was analyzed using FEM. From the FEM results, it was shown that wind resistance performance of a ceramic base with the indents consist of diameter 12mm and depth 4mm was superior to that of other ceramic bases. Secondly, wind resistance tests of the ceramic bases planted with moss were carried out and it was confirmed that for the ceramic base with good wind resistance performance obtained from the FEM results, the quantity of the moss that has been separated from the ceramic base was very small. From the above, it was clarified that wind resistance performance of greening plant with moss by arranging indents of the suitable shape on the surface of the ceramic base was improved.
The mercury target system is used for MW-scale neutron sources in the Japan Spallation Neutron Source. During this operation, cavitation damage is imposed on the mercury target vessel. It is very important to nondestructively evaluate the cavitation damage from the viewpoints of the structural integrity evaluation and lifetime estimation of the mercury target vessel. In this study, the cavitation damage was evaluated using a nonlinear ultrasonic method. First, the cavitation damage was imposed on plate specimens using an electro-Magnetic IMpact Testing Machine with 108 impact cycles. Nonlinear ultrasonic imaging was used to evaluate the damage. We found that the damping factor and higher harmonics of reflected waveforms from the damaged area can be used to evaluate the damage. An effective cavitation damage evaluation process has been developed based on our results. The evaluation process successfully detected minimal cavitation damage with peak-to-peak roughness of about 25 μm.
In this paper, influence of installation angle of the damper utilizing fluidity of particle assemblage on damping force of the damper is investigated experimentally. The experiment was performed under installation angles of 0 (horizontality), 30, 60 and 90 (verticality) degrees. It is found that damping forces under 30 to 90 degrees of installation angles are larger than that under 0 degree of installation angle when the piston of the damper moves downward. And maximum damping force takes largest value at 60 degree of installation angle. On the other hand, by using inner capacity variable damper which comprises spring, installation angle has any influence on characteristics of damping force of the damper.