Indikasi Kerusakan Dingin pada Mentimun Jepang (Cucumis Sativus L.) Berdasarkan Perubahan Ion Leakage dan PH

In this study, the chilling induced in Japanese cucumber (Cucumis sativus L.) stored at chilled temperature and the changes in its quality during storage period were examined. Change in ion leakage and pH were used as indicator of chilling injury symptopms. The sample of cucumber were stored at 5ºC (chilling) and 25ºC (non chilling). Percentage of ion leakage for cucumber stored at 5ºC was higher than that at 25 ºC at storage time of 3, 6 and 9 days. The increase in the rate of ion leakage at 5ºC indicates the chilling induced of cell membrane. The increasing tendency of pH was observed for cucumber stored at 5ºC with the value at storage time of 9 days were higher than that at 25ºC. The increase in pH could be thought as the change in acid content which indicate the occurrence of chilling injury. Changes in ion leakage and pH indicate the change in membrane permeability which related to chilling injury

Transmission electron microscopic observations of nanobubbles and their capture of impurities in wastewater

Unique properties of micro- and nanobubbles (MNBs), such as a high adsorption of impurities on their surface, are difficult to verify because MNBs are too small to observe directly. We thus used a transmission electron microscope (TEM) with the freeze-fractured replica method to observe oxygen (O2) MNBs in solutions. MNBs in pure water and in 1% NaCl solutions were spherical or oval. Their size distribution estimated from TEM images close to that of the original solution is measured by light-scattered methods. When we applied this technique to the observation of O2 MNBs formed in the wastewater of a sewage plant, we found the characteristic features of spherical MNBs that adsorbed surrounding impurity particles on their surface