According to the research entitled “the innovative engine prototype powered by diesel and LPG as fuel for agricultural” in 2019 the problems found while using the engine were as follows: the accumulated heat in the auxiliary combustion chamber reached 300 C in case of gasoline engine use and a lot of black smoke in the exhaust was found at the speed higher than 1800 rpm in case of a diesel engine use. In order to extend the research and solve two foresaid problems the objectives of this study were 1) to develop an auxiliary combustion chamber for cooling 2) to develop a scalable gas-air mixing device and 3) to compare diesel and LPG consumption rates by modifying a small diesel engine Yanmar version TF120DI to install LPG fuel systems and ignition system. In addition a gas-air mixing device was modified while an auxiliary combustion chamber was developed to reduce the compression ratio to the same level as the gasoline engine for replacing the position of the original diesel fuel injector. This method could support LPG fueling only whose function was characterized by the function of a gasoline engine. The auxiliary combustion chamber could be removed and then installed a diesel injector to return using diesel fuel. From an experiment to compare the modified engine operating as a gasoline engine it was found that the temperature of the auxiliary combustion chamber and the temperature of the engine cylinder head of Honda GX160 were measured at the maximum speed of 182 C and 186 C respectively. It was found that carbon monoxide content was 0.41 % and 1315 ppm hydrocarbons. When used as a diesel engine it was found that the black smoke was exhausted at 1.5 % which was similar to the diesel engine before the modification. From the experiment of using the power engine for pumping water with an Irrigation propeller pump with the diameter of 8 inch at a constant engine speed of 1000 rpm it was found that the average diesel usage was 0.65 kg/hr or about 0.77 L/hr with the cost of 21.00 Baht/hr and if using LPG as fuel the average LPG consumption was 0.57 kg/hr with the cost of 13.71 Baht/hr which could save up to 34.71 % of costs.

This research aimed to experimentally study of solar panel efficiency with water cooling. Three mono-crystalline solar panels with the capacity of 80 W (for each panel) were used for this test. The first panel was a solar panel without water cooling. The second panel was a panel with water spray cooling. The last panel was a solar panel with water drop cooling. The cooling water flow rate was varied to 50 75 and 100 LPH. From the test it was found that the temperatures of all solar panels had the similar trends. The solar panel efficiency decreased when the temperature of solar panel increases. The solar panel efficiency increased when the cooling water flow rate was increased for both of water spray cooling and water drop cooling. For all water cooling flow rates the water spray cooling solar panel performed higher efficiency than water drop cooling solar panel. The highest solar panel efficiency in this test occurred when the water spray cooling flow rate of 100 LPH.

The objectives of this research were to study cellulose fiber extraction from rice straw with sodium hydroxide in various conditions (with 5 1 0 and 1 0 % of sodium hydroxide at room temperature 60ºC and 90 ºC for 0.5 1 2 and 3 hours) and to study rice straw nonwovens preparation by the wet-laid process. Oil wicking ability oil absorption ability air permeability morphology and physical properties of prepared nonwovens were investigated. It was found that the optimal condition for cellulose fiber extraction from rice straw was 5% of sodium hydroxide at 90 ºC for 2 hours. At this condition the cellulose fiber yield of 2 2% and the fiber length of 1 . 9 6 cm were obtained. The oil wicking ability and oil absorption ability of rice straw nonwovens increased when weight per unit area increased. Therefore oil absorbed into gaps between fibers of the nonwovens by capillary effect. Moreover the nonwovens could wick and absorb virgin palm oil better than fried palm oil because virgin palm oil has a lower viscosity than fried palm oil. The viscosity increased from derived lipid and other substances which dissolve and disperse increasing after frying food. The results indicated that the rice straw nonwovens had oil absorption ability.

The purposes of this research were to develop and to test performance of mini heat pump dryer for slice banana. Drying chamber of 0.48×0.47×0.39 m3 was designed and it could contain three trays. The three trays had dimension of 0.33×0.409 m2. A blower with 174.6 W motor of air condition was modify and could adjust flow rates of three levels for air cycle system in dryer. The air system had bypass air at evaporator. The refrigerant of R-134a and four main parts were used in the heat pump system. The four main parts were a 497 W hermetic compressor a 1800 W condenser an expansion valve and a 1300 W evaporator. Experiments for test performance of the mini heat pump dryer used close loop air system an evaporator bypass air of 60 % a temperature of 60 oC and various flow rates of 0.117 0.128 and 0.140 m3/s. Slide bananas of 400-500 g had an initial moisture content of 244-281 %dry basis and were dried until final moisture content lower than 6.24±0.007 %dry basis. It was found that the flow rates of 0.117 0.128 and 0.140 m3/s had coefficients of performance (COPh) of 3.32±0.066 3.88±0.031 and 4.24±0.08 respectively and had specific moisture extraction rates (SMER) of 184.5±11.85 186.2±8.17 and 200.1±21.34 g/kWh respectively. The flow rate at 0.140 m3/s was the best condition because it had high specific moisture extraction rate.

. In this study examination of label information physical and microbiological qualities was performed in 30 clear-plastic and 3 opaque-plastic bottled drinking water products distributed in city municipality of Ubon Ratchathani. Results showed that 12 clear-plastic (36%) and 3 opaque-plastic (9%) bottled drinking water samples had no expiry date on the product labels which were discordant to the criteria for drinking water in sealed containers imposed by the Ministry of Public Health of Thailand no. 383 (2017). Odorless appearances of all drinking water samples were observed. Values of pH in 4 clear-plastic (12%) and 3 opaque-plastic (9%) bottled drinking water samples were in the ranges of 6.21±0.00–6.29±0.03 which were below the allowable limit (pH 6.5–8.5). All bottled drinking water products contained numbers of total coliform and fecal coliform bacteria less than 2 MPN/100 mL and were devoid of E. coli. Therefore based on the quality of clear-plastic and opaqueplastic bottled drinking water products distributed in city municipality of Ubon Ratchathani 1 5 samples (45%) did not meet standard for drinking water in sealed containers declared by the Ministry of Public Health of Thailand (1981 and 2017) owing to no expiry date labeled on the products and pH value below 6.5.