This research work was to study the effect of moisture on mechanical properties of wood/polyvinylchloride composites (WPVC). WPVC specimens in ratio of PVC and wood (100:100 by weight) were prepared by using twin screw extruder. The water conditions for WPVC specimen immersion testing were varied for temperatures of 30-70 oC and specimen immersion time of 0-120 h. The moisture effect was investigated by measuring flexural properties and hardness of WPVC as comparing with case of PVC specimen. The result suggested that flexural modulus of WPVC tended to decrease with increasing time of water immersion and then remained unchanged at immersion time of more than 72 and 48 h for water temperature of 30 and 70 oC respectively. The decrease rate in flexural modulus enhanced when water temperature increased. Flexural modulus of PVC slightly changed with increasing both immersion time and water temperature. Flexural strength for both PVC and WPVC specimens were found the change at water temperature of 70 oC only. Flexural strength of PVC tended to slightly increase with increasing immersion time whereas flexural strength of WPVC slightly decreased with increasing immersion time. Hardness of PVC specimen in cases of both water temperature of 30 and 70 oC slightly increased with increasing immersion time. For WPVC hardness tended to decrease with increasing immersion time and water temperature.

For this work PM10 were collected from 7 stations within the area of North Phra Nakhon campus Rajamangala University of Technology Phra Nakhon Thailand. The samples were collected within 24 hours from January to April 2015. The result shows that the concentrations of PM10 values are in the range of 0.06 - 0.16 mg/m3 and average PM10 of 0.09 mg/m3. The maximum PM10 were found in front of the university. The comparison of maximum PM10 with the standard value of Pollution Control Department (PCD) was slightly over but did not affect human health.

This research work was to study the effect of surface treatment of natural fiber and the effects of type and content of natural fiber on the development of acoustic material from natural rubber foam /natural fiber composites. The surface treatment used for this research work was sodium hydroxide (NaOH) treatment. NaOH Concentrations and treatment times were varied from 0 to 15 %wt. and 0 to 30 min respectively. Natural fibers used for this work were bagasse fiber (BF) and oil palm fiber (OPF). The suitable condition for surface treatment was estimated by fiber length and diameter (L/D) ratio and morphology of natural fiber. The result suggested that L/D ratios tended to increase when NaOH concentrations and/or treatment times increased except for NaOH concentration of 15 %wt. L/D ratios of OPF after surface treatment were changed more than those of BF. The suitable conditions of NaOH treatment for BF and OPF were NaOH concentration of 10 %wt. and surface treatment times of 30 and 10 min respectively. The effects of fiber type and content on sound absorption properties of natural rubber foam /natural fiber composites were investigated by cell characteristics sound absorption coefficient DMA analysis and bulk density. Both treated BF and OPF with suitable treatment condition were varied from content of 0.0 to 10.0 %wt. The result showed that the cell size of composites tended to decrease with addition of natural fiber whereas number of foam cell per unit volume increased. After adding natural fiber more than 2.5 %wt. cell size of composite foam and number of foam cell per unit volume tended to change the inverse direction. Natural fiber in composites enhanced the sound absorption efficiency. Sound absorption coefficient of composites adding BF was more than that of composite adding OPF. The addition of natural fiber enhanced the elasticity of composites and that increased sound absorption efficiency. NaOH treatment led to creation of strong interfacial bonding between natural fiber and natural rubber and enhanced the sound absorption efficiency. Density of NR composite foam increased with increasing natural fiber content.

The purpose of this research was characterized the noises at North Phra Nakhon campus Rajamangala University of Technology Phra NakhonThailand. The instrument of this study was instrument noises. Volume of noise levels were measured in terms of 15 hr and equivalent sound level (Leq 9 hr). 10 samples of noise levels were collected at Rajamangala University Technology Phra Nakhon from 10 stations. The results shown that the average noises volume of 9 hours were in range of 63.10 to 71.20 dBA by measuring station with highest mean of monitoring Station Building Civil Engineering in the area of Electrical Engineering and Mechanical Engineering were found 67.68 and 67.39 dBA respectively. The results of this study indicated that volume of noises in Rajamangala University of Technology Phra Nakhon were a little bit more than the standard of Pollution Control Department of Thailand and weren’t affected to teaching and learning in North Phra Nakhon campus.

The objective of this research is to propose a new way to fabricate a composite material for future bone replacement development via growing apatite crystal on silk fibroin fiber. Apatite crystallization on silk fibroin fiber was prepared by precipitation reaction between Ca(NO3)2 solution and (NH4)2HPO4 solution adjusted pH by NH4OH solution. In this work Effect of solution concentration and initial pH values was investigated on apatite crystals. Chicken eggshells were used as calcium source by heating sufficiently powdered eggshells at 1300 °C for 4 h to acquire CaO powders made Ca(NO3)2 solution by dissolving in 65% HNO3 solution. Prepared Ca(NO3)2 solutions were adjusted concentration as 3 levels and were adjusted different pH values of 7 8 and 9 respectively. For processing of apatite crystallization silk fibroin fibers were immersed in Ca(NO3)2 solutions for 30 min. After that (NH4)2HPO4 solutions were added in silk fibroin fibers immersed in Ca(NO3)2 solutions. Reaction time was fixed about 1 min before cleaning to remove impurity precipitates on surface of silk fibroin fiber. Finally apatite crystallization on silk fibroin fibers occurred. The obtained result can conclude morphologies of apatite crystals on silk fibroin fibers was sheets sphere and flower. Solution concentrations and initial pH values directly influenced on Ca/P ratio of obtained apatite crystals by Ca/P ratio increases as increased solution concentrations or increased pH values. Finally research silk fibroin fibers were woven as two patterns of plain weave and twill weave and they were investigated Young’s modulus and tensile strength. The result indicates that Young’s modulus of silk fibroin fiber sheets woven as twill weave and as plain weave were about 616 MPa and 425 Mpa and tensile strengths of them weave were about 40 Mpa and 72 Mpa respectively. The optimum condition of growing apatite crystals on silk fibroin fibers was sample of CP19. Design of silk fibroin fiber with plain weave was an optimum pattern for future biomedical applicaions.