his research work aimed to study the effects of the addition of sisal fiber and surface treatment by epoxy silane on the physical and thermal properties of polylactic acid (PLA). Specimens of PLA and unidirectional fiber-reinforced composite were processed by a compression molding machine and evaluated the physical and thermal properties by water absorption measurement and differential scanning calorimetry (DSC) analysis respectively. The result showed that water absorption tended to increase by adding sisal fiber whereas surface treatment of sisal fiber by epoxy silane improved water resistance of composites. The water absorption values at immersion time of 5 days were 0.89 1.13 and 1.26 % for PLA PLA/treated sisal fiber composite and PLA/untreated sisal fiber composite respectively. For thermal properties the addition of sisal fiber led to decreases in glass transition temperature and crystallinity. These were because the presence of continuous fiber might interfere with the crystallization of PLA. The surface treatment of continuous fiber with epoxy silane led to difficult crystallization. The good interfacial adhesion interrupted PLA alignment.

This research had the objective to design and develop power production from daily life leftovers for their highest benefit of utilization by using the principle of quality function development and power generator that changed mechanical energy into electric energy. In developing electric generator product from air conditioner condensing unit the researcher found that there were 4 important factors including speed installation distance size and cross-sectional area of the fan and the test was conducted between 8.00-17.00 hours. The researcher collected the data and analyzed the test result and found that the best result in the test was to install the product at the distance of 10 cm by using an 18 fan in order to acquire the best voltage and the data were collected so that they could be implemented in developing such product in the future.

Direct thermal decomposition mercury analysis is an efficient technique for determination of mercury in facial whitening creams. The analysis can be performed without any sample preparation. The samples can be weighed and placed directly into the analyzer. Thus there is no chemical waste produced in sample preparation. The time and energy used in sample digestion are saved as well. The calibration curve between mercury absorbance in terms of peak height and weight of standard mercury in the range of 0.1-10 ng was created. The calibration curve was linear followed the equation y=2.003x10-2X– 5.14x10-4 with coefficient of determination (R2) 0.9991. The precision in term of repeatability were 14% and 5.9% rsd (n=3) at 1.2 and 868 µg kg-1 respectively. The recoveries were between 88-110%. The detection limit (LOD) was 0.1 µg kg-1 (3sd/m n=10). The amount of mercury detected in 12 whitening cream samples sold in Chonburi province during the year 2019 were within the safety standard permitted in general cosmetics under the notification of the Ministry of Public except two samples were over the permitted standard.

Man Lueat (Dioscorea alata) flour is a biopolymer material that can be formed into an edible film. It can be contacted directly with food consumed and naturally biodegraded. The aims of this research were to study the effect of physicochemical mechanical and thermal properties of edible film from Man Lueat flour. The film forming solution was prepared by Man Lueat flour at 4% w/w. The glycerol was used as a plasticizer. It was studied at 3 different levels; 30 40 and 50% w/w of Man Lueat flour. The film forming solutions were formed using the solution casting method and dried at 50 °C for 16 h. Results showed that the glycerol content at different levels of the edible film from Man Lueat flour had no effect on the thickness color transparency and elongation at break. However the moisture content water solubility swelling property and water vapor permeability of the film tended to increase when increasing the glycerol content. In contrast the Young’s modulus and tensile strength of films tended to decrease significantly when the glycerol content increased. Thermal properties were found that decomposition temperature of films occurred 2 stage; the first stage occurs between 50 to 130 ° C and the second stage occurs between 263 to 315 ° C. The analysis of FT-IR showed that the different levels of glycerol affected the structure of the film (3278 cm-1). Therefore the edible film from Man Lueat flour can be applied as a food packaging material to protect the quality of food products.

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.