We have optimized the conditions of electrical nucleation toward the sodium acetate trihydrate of supercooled latent heat storage device as a commercial product.
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Electrical nucleation ...was investigated by using a Ag anode with sodium acetate trihydrate crystals embedded on the surface in a supercooled aqueous solution of sodium acetate (45–54 wt%) as a latent heat storage device. Rapid electrical nucleation was achieved by applying a direct-current voltage of greater than 1.4 V. When the voltage was set to greater than 1.8 V, the induction time of the electrical nucleation increased as the number of operations increased. The Ag anode life increased when the voltage was less than 1.8 V. When the voltage was 2.0 V, the anode resistance increased as the number of operations increased, with the anode surface deteriorating and forming silver oxide. The repeat life of electrical nucleation at voltages less than 1.8 V was about two times longer than that at voltages greater than 1.8 V. The repeat performance of electrical nucleation and the stability of the supercooled solution were found to depend on the surface roughness, Ra, of the Ag anode. The Ra value was optimized to be in the range 0.6 ≤ Ra ≤ 1.0 µm.
This paper describes inner-water circulation DMFC (Direct Methanol Fuel Cell) system with low water cross-over MEA (Membrane Electrode Assembly). Water permeation controlled layer which has lower ...permeability (K~10 -14 m 2) than conventional micro porous layer (K~10 -13 m 2) was sandwiched between anode gas diffusion layer and anode catalyst layer. This layer blocks liquid water permeation from anode gas diffusion layer to anode catalyst layer and enhances water diffusion from cathode to anode. Water flux through the membrane can be changed from anode to cathode or cathode to anode based on operation parameters (air flow rate, cell temperature, fuel pump flow rate, anode circulation pump flow rate). The effect of operation parameters for water, methanol transport through the membrane and performance were examined experimentally. With these result, system operation method to control anode methanol concentration and solution volume by manipulating flux through the membrane was analyzed. As a result, the method to control methanol concentration by fuel pump flow rate and the method to control solution volume by air pump flow rate was established. This system enabled not only to achieve higher water and methanol utilization efficiency but also increased power efficiency without extra devices for cathode water condensation and recycling. DMFC total system volume was reduced for portable uses.
We report three cases of the ectopic sebaceous glands in the esophagus diagnosed by panendoscopy and biopsy. Each cases showed multiple, minute, jellowish and grannular elevated lesions ...endoscopically at the middle esophagus and diagnosed by histological examination of endoscopic biopsies. Esophagogram revealed multiple marginal filling defect with barium fleck. In 1978, Remakrishnan reported the first cases in which the ectopic sebaceous glands were observed endoscopically. It had been reported 29 cases of the ectopic sebaceous glands in Japan. We consider that the incidence of the ectopic sebaceous glands in the esophagus is not rare and the detection will be increased if we perform endoscopy carefully.
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