室温磁気冷凍技術は高効率な次世代ノンフロン型空調冷凍技術として注目されているが，一部の用途を除き実用に耐えうる冷凍能力の実現には至っていない．本研究では磁気冷凍機の冷凍能力向上を目指し，Active Magnetic Regenerator に則った冷凍サイクルの改良に着目した．数値計算から得られる冷凍能力を目的変数とし，山登り法を用いて室温磁気冷凍機における最適な冷凍サイクルを，冷凍温度幅とAMR 寸法が異なる複数の場合について探索した．その結果，磁気冷凍機で一般的に用いられることが多いブレイトンサイクルとエリクソンサイクルを複合した冷凍サイクルを用いた場合に高い冷凍能力が得られることがわかった．
The effect of pre-treatment at subzero temperature of grains on the grinding process was investigated in respect of physical properties of particle. The average particle size of ground soybean and black soybean powders decreased as pre-treatment temperature decreased. The theoretical model that described grinding characteristics revealed that the freezing as pre-treatment is effective on grinding process. In all grain samples, the Bond’s constant and work index showed lower values as the pretreatment temperature decreased. The scanning electron microscopy was used for observation of surface damages on the particles by grinding process. Some cracks were seen on the surface of particles of soybean powder ground with freezing pretreatment. On the other hand, the particles of black soybean powder showed no fractures. The freezing as pre-treatment of grains prior to grinding process is effective to controlling their grinding characteristics and microstructure damages.
Nowadays, fluorescence spectroscopy has been used as a potential method for nondestructive quality measurement of food materials. Fluorescence fingerprint (FF) of adenosine 5’-triphosphate (ATP) has been observed during the quality assessment of different raw food materials. Although the fluorescence spectra of ATP can be affected by various factors including pH, the details are not clarified yet. Thus, the study attempts to demonstrate the effects of pH (5.0-8.0) on the FF data of ATP standard solutions (10, 5 and 1 µmol/mL for both frozen and non-frozen states). The results of the present study revealed that the strength of the fluorescence signal was influenced by not only the concentration of ATP but also by the pH of samples. The highest fluorescence intensities were observed from the non-frozen ATP solutions at pH 5.0 for each concentration which declined drastically with increasing pH. The majority of frozen ATP samples showed the similar trends of wavelength conditions to get highest fluorescence intensity. Small pH changes affected the intensity and spectral characteristics of FF and it even shifted the peak wavelength conditions. The implementation of this method would be a help to ensure the validity of FF and optimize it as a technique that can be used to verify the effects of pH on many constituents of food.