The aim of this research was determine total phenolic content total flavonoid content and antioxidant activity by DPPH and ABTS assay from leaves flower and stem of Crateva adansonii DC. subsp. trifoliate (Roxb) Jacobs that was extracted by Soxhlet method using ethanol dichloromethane and ethyl acetate as solvent. Leaves extract showed the highest total phenolic content and antioxidant activity. Ethanolic leaf extract showed the highest total phenolic content (157.13±0.32 mg GAE/g extract) and antioxidant activity by DPPH assay (53.64±3.78% (IC50 = 1.49±0.02 mg/ml)) and ABTS assay (76.51±0.97% (IC50 = 0.84±0.01 mg/ml)).When we considering solvent effect found that ethanolic extract showed the highest total phenolic content and antioxidant activity. Total flavonoid content ethyl acetate extract showed the highest total flavonoid content. Total phenolic content significantly correlated with antioxidant activity.

Metal casting with Green sand mold is essential for participation in the manufacturing industry that requires natural resources and chemicals as an element. This research studied the effects of the right mix of mangosteen shell powder on green sand mold. The objective is to study and analyze the mixture of moist sand formations consisting of natural sand bentonite mangosteen shell powder and water affecting the properties of green sand mold by experiment method. Starting from studying relevant information of natural materials that affect sand mold and planning experimental design by using the experimental design program for the trial version in the experimental design and analyze results. The results showed that mangosteen peel powder had an effect on the properties Compression strength and higher hardness of sand mold but does not increase the ability to release a lot of air permeability The optimum blend ratio was composed of 90% reused sand 7% bentonite 1% water and 2% mangosteen powder by weight air permeability. The hardness of the sand casting was 0.71 kg/cm2 47.36 and 94.06 Scale B respectively.

The purpose of this research was to study hot-melt adhesives from natural rubber (Standard Thai Rubber 20 STR 20). In order to improve the adhesion and melting properties of hot-melt adhesive to get the best glue formula from STR 20 the ethylene vinyl acetate content (EVA) paraffin wax (Wax) and petroleum resin (Resin) were varied from 25 50 100 125 and 150 phr (Part Per Hundred Rubber). It was found that the best adhesive formulas consisted of 100 phr of STR 20 25 phr of wax 150 phr of EVA and 150 phr of resin. For preparing hot-melt adhesive first the wax was heated and maintained at 160-170 ºC then cut the STR 20 into small pieces and slowly added the rubber into the melted wax until the rubber was completely melted. And then added resin and EVA and cooled to room temperature finally the results show that hot-melt adhesive was dark brown hard and odorless smooth texture and easy to melt with 514±14 centipoises of Viscosity at 150 ºC 82.49±1.4 lbf/in2 of shear strength and 2.06±0.02 kN/m of cleavage peel strength.

This study investigates three different types of power plant include a trilateral cycle (TLC) subcritical organic Rankine cycle (ORC) and supercritical ORC power plant driven by geothermal heat source with mass flow rate 1 kg/s and temperature of 100๐C 110๐C and 120๐C. with 27 substances were examined as the working fluid of the power plant. While the net power output of 4.78 kW and 7.74 kW is obtained from the subcritical ORC with RC318 as its working fluid when the heat source temperature are at 100๐C and 110๐C respectively. Meanwhile the net power output of 11.85 kW is obtained from the subcritical ORC with R227ea as its working fluid when the heat source temperature is at 120๐C. The net power output of 5.64 kW and 9.16 kW are obtained from the supercritical ORC with R218 as its working fluid when the heat source temperature are at 100๐C and 110๐C respectively. Meanwhile the net power output of 12.88 kW is obtained from the supercritical ORC with R143a as its working fluid when the heat source temperature is at 120๐C. Furthermore the net power output of 7.96 kW 12.27 kW and 17.38 kW are obtained from the TLC plant with heptane as its working fluid when the heat source temperature are at 100๐C 110๐C and 120๐C respectively.

This research aimed to study the production of a biodegradable film from Jicama starch (Pachyrhizus erosus (L.) Urbar) for plant bag application. The film was prepared by dissolving Jicama starch in water to the concentration of 5 wt%. To study the effect of the glycerol content the glycerol was added at 6 levels; 0 10 20 30 40 50 and 60 wt%. The film was casted in a molded and dried at 60 oC for 24 h. After drying properties of films; thickness water activity (aw) solubility tensile strength (TS) elongation (%E) puncture strength and the degradation of the films were evaluated. The thickness of the films was in the range of 0.16-0.28 mm. The aw of films ranged from 0.36-0.49. The water vapor permeability water solubility and flexibility of the film increased with the increasing of glycerol content. Tensile and puncture strength of the starch films tended to increased when the glycerol content decrease. After the films were buried under the ground (8-10 cm depth) for 12 weeks they were degraded by 100%. The Jicama starch film with 40 wt% glycerol showed the best overall properties.