The objective of this study were 1) to develop the gas detector unit for installation on Drone and 2) to test the operational sensitivity of the developed device. The development steps included designing complying the electrical circuit testing the electrical system and online connecting system. Besides the operational sensitivity of the developed device was tested comparing the Gas Alert Micro 5 IR the reference gas detector device both in the laboratory and the field site. The results showed that the developed gas detector could detect carbon dioxide carbon monoxide and methane and displayed the results via Line notification every minute. Additionally carbon dioxide detection by MG-811 sensor gave the results similar to the reference device by 95 percent of significant level with the average amount of detected carbon dioxide in the laboratory and the field site were 700-915 ppm and 138-399 ppm respectively. However the measured results of carbon monoxide and methane from the develop device were relatively different to the reference device. Further study on carbon monoxide sensor and methane sensor calibration are recommended.

Reused cooking oil is the oil which is used more than one time and contains less than 25% (by weight) of polar compounds. Degenerative reused cooking oil is the oil which is used more than two times and contains more than 25% (by weight) of polar compounds. Major raw material of fried foods is oil. Therefore usefulness of consumed fried foods depends on the quality of cooking oil. When the oil is heated up while cooking chemical change occurs due to the reactions of hydrolysis oxidation and polymerization. These reactions cause degeneration of the oil i.e. black color rancid smell lower smoke point bubbled increased viscosity and generation of toxic substances called polar compounds. This substance can cause high blood pressure heart disease and coronary artery disease. Furthermore the reused cooking oil also contains polycyclic aromatic hydrocarbons (PAHs) - toxic mutagens which can cause cancer.

This research aims to study abrasive wear behavior of diffusion layer by pack cementation on low carbon steel. Chemical compositions of pack cementation include 42wt% Ferro-silicon 17wt% sand 3wt% NH4Cl 12wt% clay and 26wt% Liquid glass. The specimens were heated in the induction furnace at 950?C and 1050?C for 20 and 30 hrs. Microstructure of diffusion layer was analyzed with Optical and Scanning Electron Microscopy and hardness of diffusion layer was tested with a Vickers indenter. The abrasive wear tests were carried out in a Dry Sand Rubber Wheel abrasion machine according to ASTM G65 standard. Results showed that the heating temperature of 1050?C for 20 hrs. yielded high hardness level of approximately 394.26HV0.02 and low average wear resistance of 0.0751g. The worn surface exhibited deep grooves. On the other hand the heated treatment for 30 hrs. yielded the highest diffusion layer of approximately 910?m and the microstructure of Fe5Si3 ?1 and ?Fe.

This study was undertaken by using 10x10 m2 sampling plots chosen by stratified random sampling from 3 areas 50 plots for each area. Height and diameter of all trees with girth breast height (GBH) stem > 15 cm were measured. Aboveground biomass was estimated by allometric equation and the carbon stock was calculated by multiplying biomass value with conversion factor of 0.47. Result founded 4 tree species in 4 families. The Melaleuca cajuputi Powell had quite high density of 2091.31 tree/ha and other species found in some areas are Mitragyna brunonis Craib. Barringtonia coccinea Kostel. and Symplocos ferruginea Roxb with the density of 4.67 2.67 and 2.00 tree/ha respectively. Amount of aboveground carbon stock was 26.27 tonne C/ha. Mostly stem had higher carbon stock than branch and leaf at 19.92 4.94 and 1.62 tonne C/ha respectively. Average value of biomass carbon was 86.77 bath/ha.