This research objectives were to study and compare students’ behavior of electric energy saving. The samples were 900 students at Rajamangala University of Technology during 2007 academic year. They were selected by multistage random sampling. The tools used in this research included questionnaires and rating scales. The data were analyzed by statistical package program with mean standard deviation and t-test. The research finding were as follows; (1) students’ behavior of electric energy saving in 3 aspects: personal electricity consumption behavior behavior of electric energy saving in their families and behavior of electric energy saving for their community were at an average level and (2) as for students with different of genders educational levels the educational level of father and the educational level of mother there was a statistically significant difference.

The amount of dissolved oxygen (DO) in aquaculture ponds is considered to be one of the most important aspects for the survival of fishes. The water in aquaculture ponds is stratified into distinct layers with different DO caused by differences in temperature. This temperature difference occurs when the surface layer of water heated by the sun becomes hotter than the lower water layer. Since the top layer is in contact with the air it contains the most DO. On the other hand the deepest layer is isolated from the air it contains the lowest amount of DO. This study proposed an aeration system called a Solar Circulating-Water Aeration System (SCWAS). The SCWAS uses solar thermal energy to create a natural water circulation. In other words it provides an upward current of water from the bottom to the pond surface and a downward current from the surface to the bottom. This circulation creates the movement of surface water and then increases the DO content of the surface water. This water circulation moves highly oxygenated surface water to the bottom layer forcing low oxygen water from the bottom up to the surface where it can absorb oxygen. To evaluate this design concept the numerical simulations of the system were conducted using ANSYS Fluent software. According to the simulation results the SCWAS can provide the natural water circulation. It was found that a flow rate of 2.24 L/s is obtained when the ratio between the draft tube inlet (r) the draft tube outlet (R) the base (L) is 1: 2: 3. In addition an SCWAS prototype was built and installed in a tilapia aquaculture system. A calibrated measuring system was installed to investigate the prototype performance. The experimental results indicate that the average DO values at the water surface and at the bottom of the pond increased by 1.45 and 1.40 times respectively compared with those of a pond without SCWAS. Economic analysis shows that the payback period of SCWAS is 4.58 years and its investment cost is 17.49% less than that of the paddle-wheel aerator.

This project presents an electric bicycle equipped with Solar Cell which will charge the battery with a solar panel. To be used to drive electric bicycles electric bicycles can be powered by two systems that are powered by the users cycling and from brushed DC motors from battery charging with solar panels the test will be tested by charging the panel with a time interval that the output voltage value From the solar panel which time interval is closer to the actual panel at 24 volts and charged into the batteryto test whether the electric bike can actually be used by a test drive starting with a displacement speed of 10 and 20 km/h at a distance of 100 meters. Using experiments with weight sizes of 50 60 and 70 kg respectively it was found that electric bicycles can actually be used. However the above project has been made into two parts. is the part that charges the battery from the solar panel and the second part is a separate electric bicycle.

This research is to develop and experiment the hybrid solar dryer by using cultivated banana as the ingredient in the experiment. The objective is to design create and test the hybrid solar dryer that using heat energy with infrared heater. The result from the experiment of drying cultivated banana at night-time by using heat energy from infrared heater is found that at night-time experiment cultivated bananas moisture is decrease more than at day-times experiment for 61.25 %. The temperature inside the hybrid solar dryer at night when using heat energy from infrared heater is at 49.1-55.0°C. Using heat from sunlight together with infrared heater cause the cultivated bananas moisture to decrease better approximately 27 % when compare to drying with heat energy by only sunlight.

This paper presents a mathematical simulation to compared to operations a small distributed photovoltaic power plant in the distribution system. Practices transmission of electric power by small distributed solar energy With the PVSyst and IEC 61724 mathematical modeling programs the main objective was to study the % performance ratio photovoltaic power plants 5.95 MWp connected in the distribution system of the Provincial Electricity Authority voltage level 22 kV. Therefore this paper is presented as a mathematical simulation compared to operations a small distributed photovoltaic power plant in a distribution system. The results of the study show that the operation of small distributed solar power plants increases the efficiency to be able to produce the maximum electricity and continuously. The system was able to produce the highest power of 8954.9 MWh/year and had an average annual efficiency ratio of 77.84% receiving the highest solar radiation intensity and the highest annual total energy output of approximately 1837 kWh/m2