An experimental study is carried out to clarify the effect of the electric field on freezing initiation of supercooled water in a soft PVC (polyvinyl chloride) tube. It is selected for the reason that the hydrophobe of PVC is thought to maintain the supercooled state of water easily, in condition that the electric field is not applied. As water and silicone oil is filled in the tube, a triple-phase boundary is formed inside the tube. The electric field is applied from the outside of the tube by use of a pair of wire electrodes, which is set up in parallel to the axis of the tube. The experimental condition is -5℃ in temperature and 35kV DC in voltage. As a result, the PVC tube is, to some degree, effective to keep supercooled state of water steady. The electric field causes large amplitude oscillation of the triple-boundary in the tube. Application of the DC electric field is effective to initiate freezing of supercooled water, even if the water is filled in PVC tube of low wettability to water. Relative frequency of freezing initiation obtained is 1.0, and all samples began freezing within 10 seconds after the electric field had been applied.

In this research, the author proposed a supercooling phenomenon reduction PCM that suppresses the decrease in latent heat by installing a PCM with a small supercooling degree on the heat transfer surface side of the PCM with a large supercooling degree. As a result, it was shown that the supercooling phenomenon reduction PCM can reduce the supercooling degree by forming and growing solidified crystals even when the temperature is higher than the supercooling release temperature. Furthermore, the calculation results for predicting the cooling and heating characteristics of the supercooling phenomenon reduction PCM were in good agreement with the experimental values.

In this paper, we developed a magnetic field generating coil for finding out an effective magnetic field for supercooled freezing of biological tissues under the magnetic field. The range of the frequency and the magnetic flux density of the inducing magnetic field was expanded by reducing the resistance compared with the previous coil. The upper range of the frequency increased from 2 kHz to 10 kHz and that of the magnetic flux density increased from 0.3 mT to 2.0 mT. We evaluated the magnetic field dependency of the degree of supercooling of the porcine ovarian tissues using the developed coil. In supercooled freezing, it is reported that the growth of the ice crystals, which is a cause of cell destruction, was suppressed with the increase of the degree of supercooling. This result indicates that increasing the degree of supercooling may enable to prevent cell destruction. Therefore we evaluated the effect of the magnetic field by measuring the degree of supercooling. As a result of the measurement, the averages of the degree of supercooling at 10 kHz frequency of 2.0 mT magnetic field increased the most from 9.1 ± 1.7 °C for without magnetic field to 10.5 ± 1.7 °C.

一般にPCMは、冷却過程において凝固開始直前に

近年、ナラ枯れ被害が高標高、寒冷地へ拡大する傾向が見られる。寒冷地では、カシノナガキクイムシ幼虫が越冬できずに死亡することが示唆されている。そこで、本種の低温耐性を解明するため、越冬中の本種幼虫および成虫の

一般にPCMは、冷却過程において凝固開始直前に