Nitrogen is an essential nutrient for plant growth. When the plants have been grown for a long-term effect to decreased nitrogen in soil and insufficiency of the plant growth. One biological method for increasing the nitrogen content in soil is utilize of free nitrogen-fixing bacteria Azotobacter. Therefore the objective of this research was to search natural material suitable for Azotobacter fixation. The 10 natural materials were observed physical structure and investigated the ability of natural materials for Azotobacter fixation. The results showed that water hyacinth and bagasse stalks were fixed the Azotobacter of 2.43x108 and 1.94 x108 CFU per gram of each natural material respectively. After that the selected fixed Azotobacter of water hyacinth and bagasse stalks were studied the growth of Brassica Chinensis. This experiment was designed to 4 treatments. The first treatment was mixed of water hyacinth stalks and the Azotobacter. Second treatment was mixed of bagasse stalks and the Azotobacter. The third treatment was the Azotobacter only. The last treatment was soil only. The results indicated that the average of plant growth include height leaf number root length fresh weight and dry weight of the mixed of water hyacinth stalks and the Azotobacter had significantly higher growth rates than other treatments. The total nitrogen was also increased 1.4 fold in the soil. All results suggest that the water hyacinth stalk is alternative for the fixation of the free nitrogen-fixing bacteria Azotobacter as induce nitrogen in the soil and plant growth promotion.

The study of nutrient components in co-composted sludge from Serm Suk Co. Ltd. applied on Brassica chinensis growth had the objective to reduce the amount of waste from beverage processing which the factory did not eradicate properly. This experimental research helped reducing the problem of sludge eradication by using the sludge as a fertilizer. The experiment was divided into 2 sets. 1) The dried leaves and garbage 2) The dried leaves garbage and sludge. All sets have 60 . Collect data every 5 days. The growth rate of each part was measured including the height of trunk and number of leaves. Found that in the set 2 was the best nutrients the values are as follows organic matter is 30.64% (w/w) carbon is 17:11% (w/w) the ratio of carbon : nitrogen is 22:1 total nitrogen is 0.80% total phosphorus is 0.43% and pH is 6.35. It also affected to the growth of the Brassica chinensis better than set 1 and set 3. The growth of the highest level at average at 7.7 cm and the average number of leaves at 4. This set was the best ratio for growing Brassica chinensis and reducing the waste from factory as well.

This research presents the design and construction of molten brass to form the basis of induction heating. It is heated by the half-bridge voltage source in series resonant load by transferring the heat energy through the graphite crucible for 300 grams melting of the brass in 10 minutes. The system is controlled to operate at a higher frequency than the resonance frequency mode with the input three-phase AC voltage 380 V 50 Hz through a rectifier into a DC voltage to be supplied to the inverter supply voltage half-bridge about 35 kHz switching frequency at the rated power 4.5 kW

The objective of this research is to investigate microstructure and mechanical properties of brass welded by diffusion welding process. The diffusion welding (DW) of brass welded over lap joints bonding parameters were pressure at temperature 500 650 and 800 0C contact pressure of 12 MPa and holding time for 60 minutes respectively. The microstructure mechanical properties and behaviour during bonding were investigated. The results show that in weld zone (Bond Line) diffusion of atom the brass significantly. The mechanical properties after diffusion welding process increased higher temperature