The objective of this paper is to present experimental results on absorption characteristics of irradiation energy absorbed on the narrow channel wall of a regenerated desiccant rotor. Energy absorption rate was measured in conditions of different channel lengths, incident irradiation angles, temperatures and humidity. The results indicated no influence of ambient temperature and humidity on energy absorption rate, and showed symmetry with respect to the irradiation incident angle. In addition, two prediction models were proposed and examined to evaluate the absorbed energy distribution rate. Both models reproduce the measurements well. Among them, the prediction model based on view factor in radiative heat transfer is simpler than the other. These models are useful to predict desorption rate of water vapor in a desiccant rotor in which concentrated solar irradiance is used to heat and desorb from the rotor wall.
Freeze denaturation of myofibrillar protein prepared from winter silver carp and its suppression by sucrose when frozen as mince and washed mince was investigated. The ATPase activity and salt-solubility of myofibrillar protein were measured as the indices of myosin denaturation. Sucrose at 8% was used as cryoprotectant. All samples (with and without sucrose) were frozen at different freezing -rates (1, 0.1, 0.01°C/min) and then stored at -40°C, -20°C, and -10°C for one month. Ca2+-ATPase activity decreased to near 50% just by freezing for the washed mince, while the remaining activity for minced meat was about 80%. Addition of sucrose suppressed the Ca2+-ATPase inactivation by freezing and kept near 100% activity regardless of the freezing rate. Myosin denaturation was determined by the frozen storage temperature, showing high remaining activity for the samples stored at lower temperature (-40°C). However, decrease in Ca2+-, Mg2+-ATPase activity and salt-solubility upon frozen storage was almost completely suppressed by adding 8% sucrose, even if the storage temperature was -10°C. These results indicated that sucrose at 8% was sufficiently high for protecting myosin denaturation. It is also suggested that the utilization of surimi is promising for the unstable winter silver carp.