Mobile devices are becoming more functional, thinner and having waterproof function. Therefore, heat is easily stored inside a mobile device. As a solution to the problem, heat conduction sheet was developed, but its heat diffusion effect is not sure. In this situation, simple analysis model was proposed for heat conduction sheet. In this report, cooling characteristics of heat conduction sheet were investigated experimentally, and validity of numerical prediction using the simple analysis model was verified.

Three-dimensional numerical analysis was performed to clarify the frequency response and heat transfer characteristics of the nanofluid to the gravity modulation under the microgravity environment. Gravity modulation was modeled as a sinusoidal oscillation of gravity. The frequency response of the nanofluid is good at low gravity modulation frequencies, so a heat transfer rate becomes high when the gravity modulation maximizes. Also, the heat transfer rate becomes maximum when the volume fraction of nanofluid is low. On the contrary, since the frequency response is poor at high gravity modulation frequencies, the time variations of the heat transfer rate are not observed. Therefore, the heat transfer rate is constant, and always the maximum at the low volume fraction. In the low frequency range, the time averaged heat transfer rate increases as the average temperature of nanofluid increases, and then the oscillation amplitude of heat transfer rate becomes large as the diameter of nanoparticle increases.

Impingement behavior of iso-octane spray injected from DGI nozzle was investigated. Adhesion behavior was evaluated by adhered mass and adhered area. Ground glass was used in order to evaluate the adhesion behavior. Adhered mass increased with increasing the injection period. The adhered film area was able to evaluate with ground glass. When fuel spray adhered on a ground glass wall, the light transmitted only through adhesion area of liquid fuel. This liquid film area where light was transmitted was observed from bottom direction. Adhered area of iso-octane spray on a ground glass wall was measured under injection pressure condition (Pinj= 3.0MPa) and two impingement distances (z= 30 mm and 50 mm) with dry wall and wet wall conditions. Fuel injection was varied by injection pattern. The total injection period was 15 ms for single shot injection (case1). As for the 3 shot split injection, interval of split shots was 5 ms in Case 2. Injection period of each split shot was 6.8 ms to keep the same total injection mass as the single injection. It means total injection period of 3 shot split injection was 20.4 ms. Area of fuel film was evaluated at during and after fuel injection by analyzing the bottom view image taken with a high speed camera. After injection finished, adhesion area still increased until a few milli-seconds elapsed under dry wall and wet wall conditions. It was the same as adhered behavior of case1 and Case2.

This study experimentally investigated the heat transfer characteristic of a fin with built-in closed-loop self-oscillating heat pipe by using surfactant aqueous solution. The fin part of test plate consists of 10 turns of small closed-loop meander channel. Two kinds of surfactants are used and the effects of surfactant concentration, base temperature of fin and fin thickness on the heat transfer performance of the fin with built-in closed-loop self-oscillating heat pipe are investigated. The result showed that the fin efficiency of surfactant aqueous solution case was improved due to the enhancement of boiling heat transfer by lower surface tension. When the base temperature of fin was higher, the effect of surfactant was not observed. On the other hand, when the base temperature of fin was lower, the surfactant aqueous solution case enhanced boiling heat transfer compared with water case. Moreover, the effect of surfactant concentration became larger. In the case of thinner fin thickness, it was found that the effect of surfactant was not clearly seen.

Surfactant solution flow is known for dramatic reduction in turbulent friction drag and heat transfer reduction effectiveness on temperature. When surfactant solution show drag reduction, thermal boundary layer ware also made near the heating wall. In the present study, the distribution of mean temperature and temperature fluctuation in the thermal boundary layer were measured with a fine-wire thermocouple and Two-dimensional channel. We found the relation with drag reduction characteristics to local heating of the channel and thermal boundary layer.

Recently, hydrogen has been paid attention as a clean energy because hydrogen has little environmental load and high energy conversion efficiency. However, hydrogen must be in high concentration when it is used for energy source such as fuel cells. In this study, we propose a simple hydrogen refinement method utilizing the Soret effect that the concentration gradient increases with the increase of the temperature gradient. We fabricated the device that focused on optimizing a single element of the network device manufactured in a previous study. In this study, we prepare several single element devices using experiments and CFD analysis. In the experiments, we measured two gases that were reduced concentration and increased concentration. In the analysis, we compared the hydrogen concentration at the outlet and checked the condition of re-mixing from velocity vectors and contour diagram. From the experimental results, the concentration improvement of about 0.1% was confirmed as the experimental value, and it was 1/10 of the theory value. From the CFD analysis results, the concentration improvement of 0.38% was confirmed in the small angled device, and the effectiveness was confirmed compared with the basic pattern.

This study focuses on the decomposition reaction characteristics of micro-glow corona with solid materials. Micro-glow corona is a very small plasma, which is able to be generated on the tip of a needle electrode at atmospheric pressure. In this study, a hollow electrode with an inner dimeter of 4 mm was used as a counter electrode to generate the micro-glow corona. In addition, a small plate electrode was set behind a solid dielectric sample to keep the micro-glow corona by barrier discharge. AC voltage at 100 Hz was applied to the needle electrode. When the gap distance between the needle electrode and sample was changed from approximately 0.5 mm to 10 mm, the discharge current and discharge onset voltage of the micro-glow corona were investigated. Deterioration was observed in a small area of the sample surface after discharge.

PM formation from hydrocarbon combustion field was troublesome problem for environmental emission and human health. It was formed from fuel rich combustion field under a certain temperature condition. The mechanism of PM formation is fuel pyrolysis and its partial oxidation. In this study, pyrolysis and PM formation behavior in a benzene mixture were investigated using a flow reactor system. As the result, it was conformed that benzene pyrolysis with zero O2 condition formed SOF like PM, whereas dry soot PM was formed under high temperature and O2 exist condition. SOF like PM under low temperature condition increased with an increase of O2 concentration in the mixture. Much of dry soot PM was formed under high temperature condition but it was oxidized with an increase of O2 concentration.

Porous filters are widely used as a means of removing harmful substances in the atmosphere or water. They realize the required functions by trapping and depositing harmful substances contained in the fluid inside or on the porous substrate. We developed a numerical simulation technique on the scalar transport field in the permeate flow of the porous layer using Lattice Boltzmann Method (LBM). Spatial variation of porosity and thermofluid propreties in porous layers were taken into account in the developed LBM model. A LBM simulation by the developed model on a permeate flow with chemical speies and heat transfer showed a good agreement with those calculated by finite element method (FEM).

Screen printing is a widely used technology in electronics manufacturing. To realize finer and higher aspect-ratio pattern with screen printing, massive efforts have been made. Nevertheless, as researches advance, problems such as insufficient filling have become the obstacle for further improvement of screen printing. To solve these problems, it is necessary to predict slurry behavior in screen printing process. Slurry generally has the property of thixotropy and the larger the shear rate of slurry is, the lower its viscosity is. The thixotropy makes it difficult to analyze the slurry behavior in screen printing process. In this study, we focused on the slurry behavior in ink reservoir right below the squeegee, which is fit to the simulation model in particle method. Meanwhile, we demonstrated the reliability of simulation result with a visualization experiment. As a comparison, we also carried out simulation and observation experiment with Newtonian fluid which had no thixotropy. The slurry was rolling in ink reservoir right below the squeegee. The flow rate distribution near the surface of the slurry in ink reservoir was revealed. It was found that from the area close to the substrate to the area far from the substrate, the change in the flow rate near the surface of the slurry in ink reservoir was significant than that of the Newtonian fluid. The thixotropy of the slurry was confirmed.

Photovoltaic (PV) modules are affected by environmental factors, such as operating temperature, solar radiation, and wind velocity. The effect of these environmental conditions will verify the conversion efficiency of PV module due to the increase of the PV module temperature. In this study, an evaluation system was constructed to control the module temperature. The conversion efficiency of the single crystal silicon cell was measured with the increase of the irradiation intensity by changing the module surface temperature. Experimental results showed that the conversion efficiency decreased to 8.1[%] by increasing the integrated power from 1000[W/m²] to 6250[W/m²]. The conversion efficiency is linearly affected by cooling the back surface.

In this study, the horizontal temperature distribution on a heated disc in a cyrindrical flow channel has been measured to undestand heat transfer in the chemical vapor deposition reactor. For air gas flow, the time course of temperature had both regular and irregular oscillation because of natural convection. The more the distance between the gas inlet and the heated disc made the more the amplitude of the oscilation. This tendency became more remarkable at the edge of the disc because the rotation speed of natural convection could increase with the distance. On the other hand, for hydrogen gas flow, the temperature at all positions was at almost steady state and higher than that for air flow. The reason would be why the Peclet number for the hydrogen was much less than that for air. For Rayleigh number Ra < 500000, the average Nusselt number Nu_av was almost 5 independently of Reynolds number and kind of gas. On the other hand, for Ra > 500000, Nu_av increased dramatically and approached to about 11. It was predicted that the growth rate at the edge of the disc could be greater than that at the center in these experimental conditions.

This paper describes a relationship between water content and thermophysical properties of printing papers. The general printing paper consists of lots of plant fibers. Hence the printing papers are open to influence of humidity. Due to the effects of humidity and surrounding temperature, the physical properties of the printing papers are affected and this causes change of the printing quality. In this report, in order to achieve an optimization of the printing process for the reduction of power consumption while improving the printing quality, we tried to evaluate the relationship between thermal conductivity of the printing paper and the water content. Especially, by using the combination of the steady state absolute thermal conductivity measurement method and Modelica simulation, we evaluated the effects of water content on thermal conductivity quantitatively.

The purpose of this study is to develop a new process for making a silicon plate thinner than 100μm. A silicon plate thinner than 100μm will became flexible and be utilized for flexible solar panels. If we can produce a silicon plate thinner than 100μm, solar panels could cover any surfaces. It creates new additional value of the panel products. In this study, we did the experiment using a substitute material (low melting point alloy). In our experiment, the molten alloy was pulled out from the narrow slit of the crucible and was solidified by ambient air cooling. Through this method, we can obtain the thin metal plate. We did also CFD simulation focusing on its solidification process. From the experiments, we obtained a partially thin plate with constant plate width in our experiment. Its thickness at thinnest point of the metal plate was 90μm. We need to make a more uniformly thin metal plate. We also reproduced the solidification process of molten alloy in CFD analysis. Because we conducted an air flow as an external force to the alloy which was in a liquid state, we need to consider this external force effect on the metal plate in the future. We report the current data including both the experiment and the calculation.

The demand of LNG is extending in recent years and requirement to store LNG with different density in same tank is increasing. When LNG with different density store in same tank, LNG is stratified. At this time, if tank is heated, LNG is occurred double-diffusive convection and phenomenon called as “Rollover”. “Rollover” caused generating evaporated gas, further LNG tank will damaged. Therefore we must consider “Rollover” when we design LNG plant. For that reason we need to create numerical tool that predicting rollover in LNG tank accurately. The purpose of this study is to establish analysis technology which can predict rollover. We calculated double-diffusive convection and evaluate density field of numerical analysis result by comparing subscale model experiment. Our experiment used two different density aqueous ethanol solution in subscale tank, and visualize density field by shadowgraph. And, we analyzed same condition in experiment condition except phase change by numerical analysis soft “ANSYS fluent”. Both analysis and the experiment result are formed density stratification in upper layer. On the other hands, in the lower layer, experiment result is confirmed “finger” and analysis result is not confirmed it. It is attributed to the mixing layer formed at the time of injection. It is specific phenomenon that occurs in the experiment and it is difficult to reproduce in numerical analysis. Therefore, it is necessary that to suppress mixing layer.

This study investigates the effects of combining supercharging and EGR in the operation of a small single cylinder DI diesel engine. The experiments used three kinds of C4/C5 bio-alcohol blended fuels, a blend of 30% 1-butanol and 70% gas oil (termed GB30), a blend of 30% 1-pentanol and 70% gas oil (GP30), and a blend of 40% 1-butanol and 60% coconut oil methyl ester (CB40). The boost pressures were varied from 100 kPa (naturally aspirated condition) to 130 kPa with a Roots blower type supercharger and the EGR rates were varied from 0 to 28.6% using a cooled EGR technique. All the alcohol blended fuels showed significant improvements in the trade-off relation between the NOx and smoke emissions at high EGR rates in the supercharged condition. Among the tested fuels, the CB40 fuel showed the largest reductions in smoke emissions while maintaining good engine performance with the supercharging and EGR.

In this study, a new method to calculate cooling loss is proposed. According to previous experimental data, the method which subtracts indicated work, friction loss, exhaust loss, etc., from input energy seems to be reasonable. However, in order to improve its accuracy, exhaust loss should be calculated more precisely. Hence, exhaust loss is calculated by tracking the state of in-cylinder gas from exhaust valve close to intake valve open using the law of energy conservation and mass conservation. In order to estimate the accuracy of this approach, various data acquired with several injection patterns and intake temperature were analyzed. When the main injection is divided and injected by two injectors with two separate common-rail systems, the reduction of cooling loss is verified both with conventional and new heat balance calculation method. In addition, when the main injection is reduced and, on the other hand, after injection increased, the cooling loss is also suppressed hence total thermal efficiency increased according to proposed calculation method.

The development and combustion of a small-volume diesel spray simulating a pilot injection was experimentally investigated in a constant volume vessel. Liquid and vapor phase of spray were visualized by Mie scattering method, and LIF method respectively under nonflammable condition. In addition, the spray combustion was also observed by high-speed shadow graph imaging. Experimental results show that the small-volume spray loses its momentum rapidly due to the throttle effect in nozzle seat section. Then, most of injected fuel remains around the nozzle exit, and it is vaporized as the result of thermal diffusion from entrained air.

Direct injection system is the technique for improvement of fuel efficiency in S.I. engine. The analysis of the spray structure is in particular important in a formation process of the air-fuel mixture. In this study, we conducted analysis of spray features injected from multi-hole nozzle for DISI engine. Here, in the experiment the spray features were grasped with High-speed video camera and Super High Spatial Resolution Photography (SHSRP), which was originally developed by the author's group. As a result, spray characteristics in the representative area were evaluated.

Supercritical DME spray combustion was observed in an optically accessible constant volume vessel under turbo charged engine-like ambient condition. Parallel light shadow graph and diffused light shadow graph method were applied to image the liquid and vapor phase behavior separately. The result shows that there is no significant difference in spray shape between supercritical and subcritical spray. This can be explained by the fact that the difference in volume between liquid and vapor is small at high pressure near the critical point, judging from the p-h and p-v diagram of DME. However, in the atmospheric ambient pressure and temperature condition, flash boiling was observed because of rapid volume expansion. The ignition timing of the supercritical spray was slightly earlier than the subcritical spray.

The effects of fuel injection timing and coolant temperature on soot and particulate emissions at stoichiometric mixture condition under heating mode were examined in a single cylinder spark ignition direct injection gasoline engine. Single injection was employed and the start of fuel injection timing was adjusted in the intake stroke. The gross indicated mean effective pressure and the 50% heat release angle were set to 0.7 MPa and 9 deg.ATDC respectively by adjusting the intake air pressure, injected fuel mass and ignition timing. Regardless of coolant temperatures, with advancing the injection timing close to the top dead center, the exhausted soot mass concentration and particulate number are increased, mainly due to more liquid fuel impinging the combustion chamber walls and resulting in wider and more rich fuel-air mixture around the walls. Regardless of fuel injection timings, with decreasing coolant temperature, the exhausted soot mass concentration and particulate number are increased. To maintain the same load and combustion phasing, more amount of liquid fuel should be injected, due to the lower in-cylinder temperature and wall temperture with lower coolant temperature, resulting in more unevaperated fuel and wider zone for rich fuel-air mixture near the combustion chamber walls. Compared to coolant temperature, the injection timing should be well designed to decrease the particulate matter emission.

The effects of DOC (Diesel Oxidation Catalyst) on nano-particle emission of a Diesel engine were evaluated by comparing the between each after-treatment system combination with and without EGR (Exhaust Gas Recirculation), in detail. The DPF (Diesel Particulate Filter) materials used in this research are SiC (Silicon Carbide) DPF and cordierite DPF. Then this paper presents the number and size distribution of the nano-particle with and without DOC by using BDF (Bio-Diesel Fuel) and JIS#2 Diesel fuel.

To maintain the performance of after-treatment devices, current diesel engine regulations require the use of on-board diagnostics (OBD). For diesel particulate filters (DPF), the pressure drop across the DPF is monitored to determine problems in the performance or PM over-accumulation. It is known that heavy accelerations during cold starting cause a sudden decrease in DPF pressure-drop. This appears to be caused by water condensed in the exhaust pipe, but no detailed mechanism has been established. The present study developed an experimental apparatus that reproduces heavy accelerations with high gas flow rate and a water supply. The results indicated that the sudden decrease in the DPF pressure drop is caused by a peeling-off and separation of the soot cake from the walls of the DPF, and the increase of the water flow rate causes the decrease of the DPF pressure drop.

Diesel engine vehicles are equipped with a particulate matter (PM) sensor for the on-board diagnostics (OBD) of the diesel particulate filter (DPF). It has been previously reported that a fraction of the ash generated by diesel engines can pass through the DPF, causing malfunction of the PM sensor. Recently, we reported that the main contributing factor for the occurrence of ash slip is condensed water passing through the DPF. However, the slip mechanism of the ash accumulated in the DPF is still not well understood. In this study, the slip mechanism of ash stored in a DPF has been investigated using a DPF, in which surrogate ash was stored. Quantitative measurements of the component of ash passing through the DPF were performed using HPLC, ICP-OES, and XRD, with varying the factors that influence the mass of the ash passing through the DPF, such as the pH of the water, the mass flow of water, and the mass of ash stored in the DPF. The mass of slipped ash increased with decreasing pH except the conditions where the pH was 1.7. When the mass of water increased, the mass of slipped ash increased. According to the experimental results, it is found that the rate of dissolution of the ash played the key role for the determination of the mass of the slipped ash.

Diesel Particulate Filter (DPF) is a very effective aftertreatment device to limit particulate emissions from diesel engines. DPF regeneration needs to be performed to avoid increased pressure loss. Injected fuel into the exhaust line upstream of the Diesel Oxidation Catalyst (DOC), hydrocarbons are oxidized on the DOC, which increases the exhaust gas temperature at the DPF inlet. It is also necessary that the injected fuel is completely vaporized before entering the DOC, and uniformly mixed with the exhaust gases in order to make the DOC work efficiency. However, ensuring complete evaporation and an optimum mixture distribution in the exhaust line are challenging. Therefore, it is important that the fuel spray feature is grasped to perform DPF regeneration effectively. In this report, the spray behavior sprayed from the swirl nozzle and the 6-hole nozzle was grasped by experimental analysis. Also, it is clarified the influence on the final HC concentration distribution from the difference in spray formation.

This article shows a research on the effect of in-cylinder flow on thermal stratified homogeneous charge compression ignition (HCCI) combustion to extend a high load limit of HCCI combustion. The study was conducted by three dimensional computational fluid dynamics coupled with simulation of chemical reactions. The in-cylinder temperature distribution was set as an initial condition. The in-cylinder flow was added before low temperature oxidation (LTO) and during high temperature oxidation (HTO), respectively. The results show that the in-cylinder flow before LTO leads to slow combustion due to heat loss to combustion chamber walls. The results also show that the in-cylinder flow during HTO is effective in fast combustion. This is mainly because in-cylinder flow expands hot burned mixture to unburned mixture, which accelerates the combustion.

In the previous study, it was shown that the ignition delay time of n-heptane/air mixture co-existing with propane was longer than the case of methane co-existence in a range of 800-900K, though octane number of propane was lower than that of methane. In this study, in order to investigate the effect of propane co-existence, chemical kinetic analysis of the ignition process of n-heptane/air mixture under co-existence of methane or propane was performed. As a result, low temperature oxidation (LTO) of n-heptane was suppressed by co-existing propane, because the reactivity of propane with OH radical was higher and propane consumed OH radicals than methane. The delay effect by propane was limited to a high temperature side of LTO range, since propane has weak LTO mechanism at a temperature range near 700K, which canceled out the OH radical consumption.

Spray mixing-controlled combustion in conventional diesel engines allow control of the heat release rate with the fuel injection rate. The low reactivity of gasoline enables a flame with an extended set-off length, the distance from the nozzle to the combustion zone, and enhances air-entrainment in the spray, maintaining the advantages of mixing-controlled combustion. However, it is difficult to control the compression ignition timing with a low reactivity fuel like gasoline. In the present study, a two-stage fuel injection strategy was employed to control the ignition with the interaction between intermediate species from the first injection and the air-fuel mixture from the second injection. Chemical reaction kinetics with CHEMKIN-PRO suggested that the ignition of PRF90 spray is promoted by intermediate species from hydrocarbons in the surrounding gas.

Hydrogen peroxide (H₂O₂) is an important intermediate species in the oxidation of fuels, whose concentration profiles contribute to the construction of the detailed chemical kinetic model of the fuels oxidation. Laser absorption spectroscopy in the mid-infrared wavenumber region is an effective technique for real-time quantitative measurements of H₂O₂ in the combustion field. However, spectroscopic parameters, such as a pressure broadening coefficient and a temperature dependent exponent, which are required for quantitative measurements, are not well known. In this study, appropriate absorption line for the measurements of H₂O₂ in the combustion field was determined in the 8 μm region and the spectroscopic parameters of the selected absorption line of H₂O₂ were obtained using a quantum cascade laser. The absorption line for the measurements of H₂O₂ in the combustion field was determined to be 1251.278 cm^-1(2.820×10^-20 cm² molecule^-1 cm^-1, ν6, 38 7 32 - 38 7 31). The pressure broadening coefficient and the temperature dependent exponent of the selected absorption line were obtained to be 0.100 ± 0.015 cm^-1 atm^-1 at 298 K, and 0.611 ± 0.065, respectively.

In this study, exhaust gas components emitted from spark ignition engine were analyzed using a comprehensive two-dimensional gas chromatograph (GC×GC) with a time-of-flight mass spectrometer (TOFMS). N-heptane was used as fuels. As a result of the analysis, the existence of components which were not considered in detailed chemical reaction model was clarified.

Since unused low-temperature waste heat at 150°C or below is large, effective utilization of low-temperature unutilized waste heat in the future is expected from the viewpoint of energy saving and CO₂ emission reduction. There are Organic Rankine cycle and Karina cycle as a power generation thermal cycle using low-temperature heat. However, these cycles have problems in terms of environmental aspects and safety. Therefore, we propose a thermal cycle using amine aqueous solution and CO₂. The gas component generated in this cycle consists of water vapor and CO₂, which has merit in terms of environmental aspects and safety. In this report, we mention the investigated result of the performance of low temperature thermal cycle using amine aqueous solution and CO₂, and show the experimental results of the cycle demonstration.

The distribution of boron in the fuel debris is one of the massive concern for the Fukushima Daiichi NPS decommissioning mainly because its distribution affects the hardness of the debris and possibility of the re-criticality. The distribution might be partially determined by the relocation behavior of the B₄C control blade. Thus, it is important to clarity the dominant factor for the variety of the relocation behavior. In particular, this study focuses on the initiation of the relocation in terms of the influence of the B₄C/SS mass ratio and SS clad thickness. The B₄C-control-rod simulant which consists of the real materials was melted and its relocation behavior was observed in a time-resolved manner with varying the experimental conditions. As a consequence, mainly two relocation modes were found depending on the B₄C/SS mass ratio and SS clad thickness. In the first mode, the B₄C/SS eutectic melt covered the surface of the specimen and large portion of the B₄C kept intact. In the second mode, the eutectic melt formed a large droplet while the specimen collapsed and large portion of B₄C was consumed for eutectic melting or enclosed in the droplet.

Relationship between Bunsen flame behavior and the density variation with transient variation in the fraction of components in the multi-component fuels has been investigated experimentally. Two blended gases which imitate natural gases were used as fuel, and air was used as oxidizer. To vary the composition of fuel transiently, the flow rate of each gas was varied linearly with mass flow controllers. The experiment was conducted under two conditions that fuel flow rate is constant and the equivalence ratio is constant. The transition time t_v was varied from 1 s to 30 s. The flow velocity was 0.8 m/s and the equivalence ratio before the transition was 0.85. The variation in the flame height was measured with a high speed video camera and the density of mixed fuel was measured with a density analyzer. Experimental results show that the density increased linearly at long t_v, while it varied discontinuously at short t_v due to the limitation of the response of the density analyzer. Under the condition of the fuel flow rate constant, the flame height decreased generally following to the density variation. On the other hand, in the case of the equivalence ratio constant, the overshoot of the flame height during the transition was observed. The magnitude of the overshoot was larger for shorter t_v. It is supposed that this is due to the time lag between the propagation of the air flow rate variation and the arrival of the fuel composition variation, at the point of fuel and air mixing.

To utilize waste glass fiber-reinforced plastic (GFRP) and to reduce water pollution in rivers and lakes, we aimed to develop a water treatment material that could purify polluted water. This is achieved by exploiting the porous nature and high permeability of ceramics produced by mixing crushed waste GFRP with clay before firing the resultant mixture. To evaluate the water-quality purification ability of ceramic, filtering tests of methylene blue (MB) aqueous solution on several kinds of ceramic samples made using GFRP containing 40% glass fiber were carried out. Then, the mechanism of ceramic MB absorption was examined by measuring ceramic specific surface area, pore size distribution, permeability and pH of the MB aqueous solution before and afire filtering. The ceramic made by mixing 60% GFRP with particle size of ~0.5 mm or less with clay before the mixture was fired at 1273K, exhibited a high MB absorptivity. The ceramic which possessed the largest specific surface area in ceramic samples had the highest MB absorptivity. The measured pH suggested that MB absorption was caused by ionic exchange. It is expected that ceramics made from clay and waste GFRP could be used as filter materials for water-quality purification.

To recycle silica byproducts and to moderate the heat-island phenomenon, a porous ceramic was made by mixing waste silica powder with clay before firing the resultant mixture. The high water-absorption capacity of the ceramic was used to produce a greening material of moss-covered porous ceramic. To examine the restraining ability of the temperature increase caused by solar-radiant heat on the moss-covered ceramic, the surface-temperature change of a moss-covered sample during solar-radiant-heat reception and the amount of water evaporated from the sample were measured simultaneously, and were compared with those of a mortar sample without moss in the water-absorbing state. To clarify the quantitative influence of the water-evaporation heat on the temperature change of the moss-covered sample, the sample temperature change was simulated by performing a thermal-conductivity analysis and by considering the heat of evaporation using finite-element-methods analysis. The experimental results confirmed that the moss-covered sample that could absorb sufficient water could constrain the temperature increase caused by solar-radiant heat for a long time compared with the mortar sample. The finite-element-simulation results indicate that the restraining effect on the temperature increase by the moss-covered sample resulted from heat of water evaporation. It is expected that the moss-covered ceramic with a high water-absorption capacity and a low conductivity could be used as a greening material on building rooftops.

To effectively utilize waste glass fiber reinforced plastic (GFRP), we have proposed a process that produces porous glass fiber-reinforced ceramics by mixing crushed GFRP with clay before firing the mixture. In this study, we aimed at developing water-permeable paving blocks that could prevent the inundation of roads caused by sudden heavy rain in urban areas by focusing on recent environmental issues because mixing crushed GFRP with clay enabled us to produce ceramics that possess high permeability and strength. In order to clarify the production conditions of the ceramics which meet both the strength and permeability criterions required for water-permeable paving blocks, various specimens were made by changing the mixing ratio of GFRP with clay, the particle size of GFRP and the firing temperature, using GFRPs containing 40 - 60% glass fiber. Bending strength, compressive strength and permeability tests were then carried out on the samples. The results indicated that in case of using GFRP containing 40% glass fiber, ceramics met the criterions of water-permeable paving blocks when the mixing ratio of GFRP, the particle size and firing temperature were 40%, 0.5 mm or less, and 1,100°C, respectively. In the case of using GFRP containing 60% glass fiber, ceramics met the criterions when each condition was 40%, 0.5 mm or less or 0.5 ~1.0 mm, and 1,100°C, respectively.

In many factories, there are machines and equipment generating heat in operation. In order to prevent excessive temperature rise, cooling water needs to be run through the machines. The cooling water is called equipment cooling water and is usually fed using chillers or refrigerators. But, due to they have compressors, the electricity consumption is high. The authors have been proposing “free-cooling system”, which can produce the cooling water using not those machines but cooling towers. In this paper, consideration is restricted to flow rate of cooling tower circulating water and cooling tower capacity in free-cooling. Resulting temperature and other various temperature values are calculated based on the heat balance inside the heat exchanger. It is found that a decrease in the circulating water to a certain extent has little influence on the cooling water temperature. On the contrary, that sometimes makes the temperature even lower in case of using a large capacity cooling tower.

A vibration mill, which had ring media in place of the ball medium of a conventional vibration mill, was developed for effective pretreatment of lignocellulosic biomass to produce the bioethanol. By the circular movement of a mill chamber on the vibration mill, the ring media might roll along the inner wall of the mill chamber. And the centrifugal force generated by the rolling motion of the ring media might act on the mill chamber wall to perform pulverizing of biomass. However, the actual movement of the ring media during pulverization was still unobserved. To observe a movement of ring media, a cover with observation window, which enabled visualization inside the mill chamber, was machined. The behavior of the ring media was recorded through the observation window by a high-speed camera with 420 fps. As a result, movements of two ring media contacted with an inside face of the cover were restricted. It was caused by a friction between side faces of ring media and the cover. Then thin ring media set at both ends of ring media and increasing number of the ring media at midsection increased active ring media contributing to pulverizing.

Recently, a lignocellulose conversion technology is required for biomass into fuels and chemical products. However, a pretreatment of lignocellulosic biomass is needed before bioconversion process, since it has the recalcitrant structure. In this study, the effect of the ozone treatment on the cedar powder was investigated by the lignin quantification test and the enzymatic saccharification test, in anticipation of combined a pretreatment of mechanical pulverization and ozone treatment. Before ozone treatment, the cedar powder was sieved into three particle size, using meshes of 2, 0.6 and 0.4 mm. And also the moisture content of cedar powder was adjusted for three conditions of 30, 40 and 50 %. As a result, the Klason lignin content in the cedar powder was decreased with the increasing ozone treatment time. And also the enzymatic saccharification efficiency of the cedar powder was increased. It was suggested that the enzymatic hydrolysis was improved by decomposed lignin. In addition, the cedar powder with high moisture content showed a good reactivity with ozone. On the other hand, the cedar powder with a small particle size did not react well with ozone. Therefore, when combining mechanical pulverization and ozone treatment, it was expected ozone treatment before pulverization to be better.

A vibration mill, called a “tandem-ring mill”, which has cog-ring media in place of the ball medium of a conventional vibration mill, was developed for mechanical pretreatment of lignocellulosic biomass. In this study, a production possibility of rice flour using the tandem-ring mill was investigated. The comminution tests of rice were carried out at different comminution media and rice loading. And the particle size and damaged starch of rice flour were estimated. As a result, a comminution force and comminution time were largely concerned with particle size and damaged starch of rice flour. Moreover, it was effective to control with comminution time based on the contact stress per unit weight of rice to suppress the damaged starch maintaining in fine particle size.