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.

Aluminium alloys was used in the automotive parts industry increased for compensate steel parts material due to its lightweight and good surface. Since aluminium alloys are there relatively low mechanical properties although they can be deformed easily but the major limitation is their low formability. Especially the less bending radius which is often bending surface damaged easily. In the present work five-difference ratio of sheet thickness and bending radius for study to the bendability of cold rolled aluminum alloys AA6016 at low bending radius. The bending test by Air-bending method according to ISO 7438: 2010. To compare the results every 15 degrees. The mechanical behaviour surface roughness microstructure and damage evolution in the fillet region were analysed by experimental research. The experiment clearly showed that the Spring-back angle and bendability tend to decrease as the bending angle and material thickness increase. Due to the high tensile stress on the bending surface it effected to the surface roughness increases rapidly and led to the damage on the specimen bending surface. The initial cracks occur on the middle of the outer surface curvature and propagation in the shear plane pattern to the middle of the sheet thickness along the grain boundary. This is the consequence of plastic deformation by bending test.

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.

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.

In this work solar erythemal ultraviolet radiation (EUV) which affects human skin and skin cancer was investigated at Songkhla province (7.2°N 100.6°E). EUV was converted to UV index then the data was used for model development and forecasting of hourly UV index using Artificial Neural Network (ANN). The ANN model has one input layer two hidden layers and one output layer. This input layer consists of extraterrestrial erythemal ultraviolet radiation solar zenith angle aerosol optical depth and cloud index which affect ultraviolet radiation and the output layer is hourly UV index. The results show that hourly UV index obtained from ANN and that from the measurement are in reasonable agreement with root mean square difference of 12.8% and mean bias difference of -2.4%. For forecasting of the hourly UV index the data for 7 days earlier was used for forecasting the next UV index for one day or nine-hour (08:00 am.-16:00 pm.). Multi-layer perceptron and back propagation algorithm were used in the model forecasting. The results show that the UV index from the model forecasting is reasonable agrees with UV index from measurement with root mean square difference of 17.0% and mean bias difference of 0.3%.