. This research aimed to study the acidification processes of carving vegetable using acid conditioning machine under emperature and pressure control which was developed in this study. Four acidification procedures were done at normal atmospheric pressure (method 1) under vacuum pressure for 10 (method 2) and 20 min (method 3) and vacuum pressure alternating with normal atmospheric pressure for each of 1 hour. There were two main parts of acid conditioning machine including the temperature controller inside the pickle tank and heat conductor tank and the pressure controller inside the pickle tank. The pickling temperature was stabled at 40oC under the pressure of 0.5 Bar. PLC (Programmable Logic Controller) program was used to write the ladder for controlling all processes and display through SCADA system. The results showed that the acidification method by soaking the carved-rose carrot under vacuum pressure alternating with normal atmospheric pressure showed the shortest time to equilibrium by 7 hours. Then the carved-rose carrot was packed in the glass jar followed by sterilized in boiling water for 15 minutes and stored at room temperature for 7 days. Total bacteria count Escherichia coli and Yeast-mold were not exceeded than the standard limit. Staphylococcus aureus was not detected throughout the storage periods

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 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.

The objective of this research is to study the combustion behavior of a gas-saving burner S-10 using computational fluid dynamics (CFD). The simulation model was created using Fluent 6.3 in 3D-model of the same size of the burner. LPG pressure of 4 psi was released for this study. The combustion behavior was shown in temperature contour and velocity vector. The CFD results were verified by measuring the temperature around the burner head with a vessel. From the study it was found that the CFD’s results of flow velocity and combustion temperature distributions were validated with the experimental values. The CFD’s result errors were less than 10.35% and 11.87% comparing with the velocity and temperature measurement respectively. The fluid flow and combustion behaviors can be described by this CFD model. Moreover the CFD model of the gas-saving burner S-10 can be applied to improve the thermal efficiency of the burner in the future.

The objective of this research is to study the combustion characteristic of a low-pressure vertical port burner using computational fluid dynamics (CFD). The simulation model was created using Fluent 6.3 in 3D-model of the same size of the burner. The CFD results were verified by measuring the temperature around the burner head and a vessel. Moreover the results of conventional vertical port burner having the swirl angle of 90o and the inclination angle of 90o (CB-S90I90) and two swirl port burners (SB) being SB-S90I13 and SB-S30I90 were compared. The temperatures obtained from CFD and experiments were similar which the error was less than 9%. From the CFD’s results the temperature and heat flux of the SB-S90I13 burner were higher than those of the CB-S90I90 burner. The maximum temperature and heat flux of SB-S90I13 burner were 1445 K and 5291 W/m2 respectively. It was implied that the combustion characteristic and heat transfer to the vessel of SB-S90I13 burner was better than that of CB-S90I90 burner. It was resulted that the thermal efficiency of SB-S90I13 burner was better than that of CB-S90I90 burner which was the percentage energy saving of 6.93%.