A heat transfer model of the evaporator in an absorption chiller was developed by modification of Nusselt's film theory. This liquid film model was found to agree with existing experimental correlations in the film Reynolds number region in which the tube is assumed to be fully wetted. Next, two-dimensional numerical computations of vapor flow in the evaporator/absorber were performed with boundary conditions of the evaporator and the absorber respectively derived from each liquid film model. The results showed that the velocity distribution around the evaporator and the velocity field between the evaporator and the absorber are different from those when the vapor evaporates uniformly on the surface of the cylinders in the evaporator.

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Silicon single crystal rods for semiconductors have mainly been manufactured by the Czochralski method, in which the quality of grown crystal rods is affected by the melt flow. In this study, experiments were carried out with a model system of the Czochralski melt under rotational horizontal magnetic fields. The temperature distribution in the melt was measured over a range of magnetic strengths and rotational rates of magnetic field. A pair of permanent magnets was used to generate the magnetic field, and a low rotational frequency (0.05–0.8 Hz) of the magnetic field was applied to the Czochralski melt. Asymmetric temperature distributions occur in the melt and rotate in the same direction as the crystal in the absence of a magnetic field or in a static horizontal magnetic field. Under a strong magnetic field or one rotating at a high rate, the temperature distributions rotate in the same direction as the magnetic field, even when this is opposite to the rotation of the crystal rod. The periodic temperature oscillation is caused by the rotation of the asymmetric temperature distribution in the melt. The oscillation period strongly depends on the rotational magnetic field.

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To improve the output performance of a desiccant humidity conditioner, a hybrid type combining heat and microwave irradiation was proposed, and the effect of heat and microwave irradiation on adsorbed water-vapor desorption from zeolites was studied.
Two kinds of zeolites (4A, 13X (DF-9)) with different pore distribution and water vapor equilibrium adsorption amount were used to investigate the effect of microwave irradiation on the water desorption rate. Experiments were carried out in a N₂ flow (flow rate of 1.62–6.36 m/min) type adsorption zeolite-packed column equipped with a microwave irradiator. Desorption performance of water from zeolites by microwave heating under the conditions of N₂ gas of 30°C with relative humidity 40% and microwave power of 800 W was compared with that for hot-air heating at 40–80°C and microwave power of 50 W. The following results were obtained.
1) The effect of microwave irradiation was found to be better than that of hot air heating for both zeolites. The amount of water desorbed from zeolite 4A, from which desorption is difficult, and from 13X (DF-9), which has a high water vapor adsorption capacity, was respectively 2.22 and 2.59 times larger by microwave irradiation than by hot air heating. This amount corresponded to that obtained by hot-air heating at 13–43°C higher than the zeolite bed temperature.
2) The desorption rate increased with the increase in pore size of the zeolites. Moreover, the desorption rate from zeolite of same pore size increased with the increase in the amount adsorbed.
3) The desorption effect of microwave irradiation was confirmed from the results of the temperature rise experiments during hot air heating and during microwave irradiation.
4) The desorption ratio showed a minimum value with respect to air flow rate.
5) For the same desorbed amount, the temperature of hybrid hot air and microwave irradiation type is lower than that of hot air heating. The microwave irradiation showed the effect of a maximum 16°C decrease of the heat source.

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The drying of thin film coating with a surface-wiping process was modeled numerically. A one-dimensional diffusion equation for a PVAc-toluene system was solved by taking into account temperature/concentration-dependent diffusion coefficients and solvent vapor pressures to obtain solvent concentration profiles. The numerical results revealed a peak in the concentration profile at a particular thickness in the wiping process due to diffusion of solvent from the wiping layer to the coating. The resultant increase in residual solvent contents gives rise to a significant drop in solution boiling point, leading to the occurrence of boiling periods during drying.

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To clarify the mechanism of coupling phenomena such as heat, mass (gas, water droplet) and electric charge transfer in a single-cell polymer electrolyte fuel cell (PEFC), in-situ temperature measurement under power generation was carried out by use of thermography, since temperature distribution plays an important role in coupling phenomena. By using a single cell filled with an observation window, the in-plane temperature distribution on the opposite side to the gas channel of the separator could be measured when the positions of the gas inlet and outlet of the cell and the gas flow rate at the inlet were changed. Gas flow rate at the inlet and outlet of the cell, gas temperature and dew point at the inlet of the cell, current and voltage were measured at the same time, and their relationship with temperature distribution was investigated. It was found that the high temperature region changed when the position of gas inlet and outlet of cell at cathode was changed. When the gas flow rate at the inlet was increased over that of normal operation, the temperature over the whole observation area decreased with increasing gas flow rate at the inlet due to the cooling effect of heat convection. When the stoichiometric ratio of H₂ was set at 1.00, the power generation performance and the in-plane temperature distribution did not change. However, when the stoichiometric ratio of O₂ was set at 1.00, a voltage drop was recognized. In addition, the high temperature region shifted from the area around the gas outlet to the area around the gas inlet. In-plane temperature distribution in the observation area was influenced by the gas flow in the channel and the gas flow pattern of the separator at the cathode. Thus, it became clear that the supply method of oxygen dominated the in-plane temperature distribution and reaction distribution.

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Paper friction materials are used for a multidisk wet clutch as part of an automatic transmission. The performance of these friction materials is known to influence the clutch greatly, and this performance deteriorates due to frictional heat generated in the contact surface at engagement. Therefore, control of temperature in the contact surface is required. In this paper, we focus on the effect of oil flow on contact surface temperature, and we carried out a numerical simulation of the heat transfer. As a result, it was shown that the heat transfer by and conduction was dominant in comparison with the heat transfer by the flow of the ATF, and that consideration of thermal resistance by the oil is important to predict engagement face temperature precisely.

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A continuous hydrothermal treatment reactor of continuous biomass–water slurry flow type was developed for a biomass saccharification process. The apparent viscosity of biomass–water slurry was measured for various biomass powder sizes and various slurry concentrations to clarify the operation conditions in the continuous system. Continuous hydrothermal treatment with a high concentration of biomass-water slurry was carried out at different operation temperatures and for different operation times. Hydrothermal treatment in a batch-type reactor was also carried out under the same operation conditions. Hydrothermal treatment results in the continuous reactor were compared with the batch system results. The apparent viscosity of slurry varied with powder size and slurry concentration. Slurry containing big woody powder showed high apparent viscosity at low shear rates. The apparent viscosity of slurry after hydrothermal treatment also varied with treatment temperature and was lower than that of untreated slurry. The solubilization ratio of woody components in water did not differ greatly between the continuous system and the batch reactor, but the glucose concentration in the solution was higher in the continuous system operated at high temperature for a short time. Moreover, a tube type continuous reactor, which can operate in shorter time than a tank reactor, yielded a higher glucose concentration at high operation temperature than the tank reactor.

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This work provides an integrated performance analysis of multistage solid oxide fuel cells (SOFC). Numerical analysis shows the effects of multi-layer-built cells compared with single cells, for stacks of up to 30 cells. A large deflection of electric current occurs at the both ends of cells because of the collectors attached there. The highest temperature occurs in the middle cell of multistage cells. The multistage SOFC with more than 20 cells is not considered to be risky because cell temperature reaches the maximum level with approximately 20 cells. The imbalance in flow rate for each cell, which is generated by temperature distribution, is less than 2 percent.

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The heat island problem has become increasingly serious owing to the concentration of population and industry in big cities around the world. Therefore, in this study, we focused on a heat shield paint which can reduce thermal storage in concrete buildings in summer. Under near-infrared heating, far-infrared heating and solar heating conditions, we clarified the thermal radiation characteristics of the heat shield paint.
In an experiment under sunlight heating, it checked that the heat-shield effect of the heat shield paint under near-infrared light contained in the sunlight of the strong time zone of solar radiation among daytime is large, and that the heat-shield effect before sunrise or after sunset is small. In the experiment under near-infrared heating, when the application state of a common white paint and a heat shield white paint was compared, the heat shield paint can control the heat flux which passes inside, and the painted surface temperature is also reduced. The experiment under far-infrared heating also checked some heat-shield effect. When the heat flux which enters into the painted surface of a building is equivalent, it becomes clear that the heat shield effect by near-infrared heating is larger than that of far-infrared heating. In addition, this tendency becomes remarkable with increasing solar radiation which enters into painted surfaces.

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The thermal and hydrodynamical characteristics of an externally insulated building with a vent layer were investigated numerically and empirically to verify the possibility of the thermal controllability. It was shown clearly that the room temperature can be controlled not only by the existence of the vent layer but also by the compulsory ventilation. Since solar radiation is strong in summer, the use of the vent layer as a further cooling function is possible by keeping the vent layer open. In addition, it is possible to intercept the rise of room temperature by operating the opening-and-closing valves attached at the inlet and outlet of the vent layer so that the heat is not transported to the interior on summer nights when the outside temperature is high. On the other hand, in winter, the energy burden needed for the maintenance of a comfortable indoor environment can be reduced by closing the vent layer.

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The mechanism of fuel NO formation from pyrrole type nitrogen and the effects of H₂O concentration on the reaction mechanism were examined experimentally using a flow reactor and by numerical simulation with a detailed kinetic model. It was found that when H₂O concentration is increased, the O radical is consumed and the OH radical is produced by the reaction O+H₂O→OH+OH. Consequently, the reaction HCN+OH, the reaction by which HCN is consumed, is promoted; and the reaction NCO+O→NO+CO, the reaction by which NO is produced, is inhibited.

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The top-heat-type heat transport loop is composed of a heated section, a cooled section, a reservoir, valves and pipes connecting these components. The working fluid is circulated inside the loop by utilizing its vapor pressure, and the heat is transported downward from the heated section to the cooled section. This paper describes fundamental experiments and theoretical analyses on the operational characteristics of the loop, and discusses the temperature difference between the heat sink and the reservoir, and that between the heat source and the reservoir.
In the experiments, the transient variations in temperature and pressure inside the loop were measured, and the liquid velocity was calculated from the results, thereby clarifying the fluid-flow characteristics inside the loop. Moreover, consideration is given to reducing the temperature difference between the heat sink and the reservoir. In the theoretical analyses, a mathematical model of the loop was formulated, and its validity was confirmed by comparing the numerical and experimental results. Analyses were also carried out for varying design and operation parameters of the loop in order to reduce the temperature difference between the heat source and the reservoir.

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The top-heat-type heat transport loop previously proposed is a thermal device composed of a heated section, a cooled section, a reservoir, valves and pipes connecting these components. By utilizing the vapor pressure, the working fluid is circulated and the heat is transported downward from the heated section to the cooled section. In the present study, the liquid return line of the loop, which consists of vapor and liquid pipes between the heated section and the reservoir, was simplified to improve its airtightness, and its operation was confirmed experimentally. Moreover, based on the experimental results, the main factor to reduce the temperature difference between the heat sink and the reservoir is discussed.

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For energy saving and CO₂ reduction during idling stops, this study focused on the exhaust gas and exhaust heat of running refrigeration/freezing vehicles. We proposed a novel system which stores the waste heat by means of a chemical heat pump and recycles it as coldness for air conditioning during an idling stop, and performed fundamental experiments of the system. As it is desirable for the reaction system to store heat at the final exhaust temperature of 423 K after passage over the exhaust gas catalyst, we used the calcium sulphate (CaSO₄) gas–solid chemical heat pump.
In the heat storing step, it was found possible to store exhaust heat in the temperature range around 393 K, and the effects of heat storing temperature on heat storing rates were clarified. In the heat releasing step, it was found that cold-heat of less than 278 K was recovered in an evaporator, while hot-heat was generated in the reactor.

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Heat transfer enhancement in a packed bed reactor equipped with a heat transfer tube was studied. Bundles of carbon fibers of high thermal conductivity were attached to the heat transfer tube not only to increase the effective thermal conductivity around the tube but also to improve the contact thermal resistance between the fibers and the tube. To disperse the carbon fibers in the reactor effectively, a spiral configuration was employed. The effect of the method of fixing the carbon fibers on the heat transfer rate was investigated, and a silver paste adhesive rather than an aluminum tape was found to be suitable to fix the fibers and to transfer thermal energy effectively. The spiral carbon fibers effectively improve thermal responses of the reactor because of their lower contact thermal resistance than a carbon fiber brush.

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A method to produce oxygen-rich air by use of rotary PSA (pressure swing adsorption) was devised to reduce the energy consumed in production of oxygen. A mathematical model of this rotary PSA was developed based on basic experiments, and simulation using the model clarified the basic characteristics and guidelines for design of the rotary PSA. The energy consumption of the rotary PSA thus designed was expected to be reduced by 50% compared with conventional low-temperature processing.

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In the thermal CVD method for processing of thin film, a complicated thermal-flow field based on natural convection is formed under the thermal gradient in the reactor, and this thermal-flow field prevents uniform growth on the substrate. As a means to control the natural convection in the reactor, the effect of the gradient magnetic field in a super-conducting magnet was numerically studied on the natural convection of paramagnetic fluid as the first step of research. The fluid is contained in a vertical cylindrical enclosure, which is cooled from both above and side isothermally. The lower end-plate has an isothermally heated disk in the center, while the outer part is thermally insulated. The magnetic field is replaced with that generated by the steady electric current circulating within a single circular electric coil. When the magnetic center is placed below the heated disk, convection is rapidly induced by the magnetic force. The heat transfer rate becomes almost twice that of gravitational natural convection for the conditions studied herein. In contrast, when the magnetic center is placed at either the central height of the enclosure or the upper end plate, the magnetic force rather suppresses the natural convection.

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A numerical study of unsteady heat conduction and radiative heat transfer in a dry transcription heating apparatus of decorative sheets was performed to investigate the effect of heater angle and temperature on the transcribed body. In the heating apparatus, eight heaters are placed above the transcribed body, with four of the heaters angled against the other four at angles of 0, 15 and 30 degree. While the average temperature of the transcribed body surface rose quickly with an increase in the heater angle, the heater angles has less effect on the surface temperature deviation of the transcribed body. In addition, when the heater temperature was varied from 473 to 553 K, the rise in the surface temperature of the body became faster and the temperature variation on the surface became larger with increasing heater temperature. Therefore, the heater placements should be investigated for more rapid heating with less temperature variation.

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The effect of the rheological property of fluids on mixing time in a stirred vessel was experimentally investigated using by the redox reaction of iodine and sodium thiosulfate. An aqueous solution of carboxymethylcellulose (CMC) was used as a non-Newtonian fluid having a weak shear-thinning rheological property, while an aqueous solution of glycerol was used as a Newtonian fluid. No significant difference in mixing patterns between CMC and glycerol solutions could be seen. When Re or Re_app>215, a cylindrical circulation zone appeared around the impeller axis, and this zone determined the mixing time. On the other hand, when Re or Re_app<195, no distinct cylindrical circulation zone was observed and the upper half of the vessel was initially decolorized. Consequently, mixing in the lower half of the vessel determined the mixing time. Non-dimensional mixing time of non-Newtonian fluid was shorter than that of Newtonian fluid under almost the same Reynolds number condition.

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The hydration rate of magnesium oxide in water was experimentally measured to clarify the effect of particle size on the hydration of soft-burned magnesia. The hydration rate of magnesium oxide was proportional to the ratio of residual magnesium oxide, and inversely proportional to the increasing ratio of the magnesium hydroxide generated. The hydration rate increased with reaction temperature and decreasing mean particle size. Hydration rate constants can be estimated from the Arrhenius equation incorporating a term of particle size.

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Microbubbles rapidly shrink and collapse on receiving physical stimuli. The impulses or OH free radicals produced by the microbubble collapse are considered to have a bactericidal effect, although the precise mechanism involved remains unknown. Among bactericidal agents, ozone is highly effective in inactivating many microorganisms.
In this study, the bactericidal effect of ozone microbubbles on Bacillus subtilis was investigated by changing parameters such as outlet pressure of pump, elapsed time, concentration of ozone fed and dissolved, and microbubble formation methods. By converting ozone to microbubbles, the high bactericidal effect was obtained with a small volume of ozone.

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We experimentally investigated the effect of organic substrates on growth of Spirulina platensis in heterotrophic culture. Organic substrates added to SOT medium were sugars, organic acids and amino acids. The specific growth rate of S. platensis is heighest in the medium with added glucose, but S. platensis did not grow well in the medium with added polysaccharides. In the medium with added α-ketoglutarate, succinate or fumarate, the specific growth rate of S. platensis was negative. The metabolic path was estimated from the experimental results.

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A model for hydriding-dehydriding reactions was constructed by considering the hydrogen concentration dependency of diffusion coefficient, the particle size distribution, and the shape variation of MmNi₅-based hydrogen-absorbing alloys was constructed. The effects of the diffusion coefficient and particle conditions on the rate of hydrogen absorption or desorption for MmNi₅-based hydrogen-absorbing alloys were numerically investigated by the finite element method by comparing calculated results with the available experimental ones for pure hydrogen. When the experimentally determined diffusion coefficient was used and assumed to be constant regardless of concentration, the calculated results were in a good agreement with experimental ones. In the desorption processes, however, the results calculated with a diffusion coefficient that was dependent on hydrogen concentration showed better agreement with the experimental ones than those calculated with a constant diffusion coefficient. Thus, like that of LaNi₅-based alloys, the diffusion coefficient of MmNi₅-based alloys seems to depend on the hydrogen concentration. When particle size distribution was considered, the termination time of hydriding-dehydriding reaction was longer than when average particle size was used and it was shown that the larger particles determined the termination time. From these results, it is important to consider the particle size distributions to estimate the hydrogen diffusion coefficient in the hydrogen absorption-desorption measurements. When shape variations were considered, the reaction rate increased with an increase in the oblateness for the constant projected area. Furthermore, the reaction rate of cubic particles was larger than those of spherical and ellipsoidal particles. Thus, the diffusion coefficient calculated on the assumption of spherical particles is expected to be larger than the actual one.

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The catalytic properties of 10 mass%Pt/ACC (active carbon cloth) catalysts for dehydrogenation of methylcyclohexane and hydrogenation of toluene were investigated by using a full-scale spray-pulse reactor. The feasibility of on-site hydrogen storage and supply using organic hydrides was studied. In methylcyclohexane dehydrogenation experiments, the conversion ratio and the hydrogen evolution rate at 598 K reached 0.85 and 40.2 NL/(g·h) respectively, but remarkable formation of the by-product benzene was detected. In toluene hydrogenation experiments, the conversion ratio and the hydrogen storage rate at 523 K reached 0.56 and 100.4 NL/(g·h) respectively. From Arrhenius plots, the activation energies of methylcyclohexane dehydrogenation and toluene hydrogenation were obtained 108.9 kJ/mol and 13.3 kJ/mol respectively. In dehydrogenation and hydrogenation tests for 100 h, the hydrogen evolution rate, hydrogen storage rate and conversion ratios were stable. It was estimated that the organic hydride system to store and supply 10 Nm³/h of hydrogen could yield 4.06 mass% and 351.9 Nm³-H₂/m³ of hydrogen storage capacity.

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