Behavior of Ompok Hypophthalmus Reared Under Different Photoperiod

Fish behavior is affected by environmental condition, including photoperiod. Tounderstand the effects of different photoperiod toward O. hypophthalmus behavior, astudy has been conducted in Oktober 2015. The fish was reared in fiber tanks size100cm X 50cm dan height 40cm with water circulation system. The tanks were placedunder plastic tents that were completed with light bulb and timer to adjust the time.There were 5 treatments applied, namely Control (natural photoperiod), 24 hours dark(24D), 16 dark and 8 hours light (16D8L), 8 dark and 16 hours light (8D16L) and 24hours light (24L). Fish behavior was monitored hourly for a 72 hours periodcontinuously. Swimming and schooling activities, fish position and respons to light andfood were noted. Results shown that the photoperiod clearly affects the behavior offish. During the dark, fish tend to be in the surface, swimming actively, do not form agroup, sensitive to light and very agresive to take food provided. In contrast, during thelight period, fish less active, tend to form a group in the bottom of the tank, lesssensitive to light and less aggresive in taking food. Based on data obtained, it can beconcluded that photoperiod is affect the behavior of fish in general

Design of Portable Beverage Cooler Using One Stage Thermoelectric Cooler (TEC) Module

The Portable Beverage Cooler (PBC) has been designed to satisfy the need of cooler apparatus that could be carried easily. The utilization of this apparatus was intended to minimize the environmental damage affected by vapour compression refrigeration system using CFCs Refrigerant. The peltier effect from thermoelectric module was utilized in this PBC and called as Thermoelectric Cooler (TEC). Furthermore, heat-sink and fan were needed to ensure the cooling effect continously worked. To achieved the objectives of this machine (portable, environment-friendly, low watt, affordable), the design consideration are heat load, insulating material, weight of components, electric consumption, and dimension of the cooling box. The results of the design shows the PBC cooling box dimension is 6 cm x 6.5 x 15 cm. The insulation of the PBC cooling box are polyurethane foam and polystyrene expanded with thickness 6 mm and 5.3 mm, respectively. The alumunium plate was applied as inner wall to enhance the cooling capacity of cooling room temperature. In this PBC was used one stage of TEC that could yield cooling room temperature until 15 oC in 30 minutes operation by consuming 20 W of electricity