In this research palm oil fuel ash was utilized as a pozzolanic material in blended Portland cement mortar. The mortar was tested on the normal compressive strength and the negative effect of carbonation in indoor environment using the accelerated carbonation test of 5% CO2 in 50% relative humidity. Three palm oil fuel ash fractions of different fineness viz. coarse original palm oil fuel ash (CPOA) medium palm oil fuel ash (MPOA) and fine palm oil fuel ash (FPOA) were used for the study. Ordinary Portland cement (OPC) was partially replaced by these palm oil fuel ashes at the dosages of 20% and 40% by weight of binder. The results showed that the incorporation of the ashes affected the strength and the carbonation depths of mortars. The strengths of mortar slightly decreased with the increases in the dosage of the ash. The fineness of ash on the other hand improved the strength and the carbonation of the mortars. The mortars containing FPOA exhibited high strength and relatively low carbonation in comparison to those using coarser MPOA and CPOA. The use of FPOA resulted in a strong and dense mortar owing to the increased packing effect and pozzolanic reaction. It was therefore demonstrated that the FPOA could be used as a pozzolanic material to replace part of Portland cement for use in the indoor environment.

In this paper the effects of carbonation on pore structure of blended pozzolan cement pastes were investigated. Ordinary Portland cement _OPC_ was partially replaced with ground palm oil fuel ash _POA_ ground rice husk ash _RHA_ and classified fine fly ash _FA_. The strength total porosity specific surface area and pore size distribution were tested. In general incorporation of pozzolans increased the total porosity of blended cement pastes in comparison to that of OPC paste. Carbonation of pastes under 5% CO2 and 50% relative humidity _RH_ for 28 days resulted in filling of the pore voids and possible attack on calcium silicate hydrate _CSH_ depending on the type of pozzolan used. After carbonation total porosity decreased and specific surface areas of the blended pozzolan cement pastes reduced indicating the infilling of voids. Pore size distributions of POA and RHA pastes were different to those of FA pastes. Large pores of the POA and RHA pastes were increased indicating coarsening of pores owing to possible attack on CSH. It is possible that POA and RHA were highly reactive and hence their uses resulting in severe carbonation compared to use of FA.

This paper presents the analysis of electric field by using FEMLAB simulation tool to find the optimal electric field and component designs. Design of Cable terminator is tested by finding PD Value with IEC standard. This paper also proposes the electric stress when we design the cable terminator includes SF6 insulator. The modeling design is very useful for High Voltage engineers to find the optimal solution of Cable terminator design.

The objective of this research is to study the factors of resource and investment affecting to the number of post graduate students of Rajamangala University of Technology Phra Nakorn. The samples of this research are to survey the group of lecturers from 9 faculties by answering the questionnaires.

A microstrip folded ring resonator sensor for measurement of dielectric constant in a compact area of material under test is proposed. The resonant characteristics of resonator vary with dielectric constant of material. Limitations in the microwave frequency response performances of the proposed sensor have been carefully studied in a range from 500 MHz to 3 GHz. It has been found that the proposed sensor has great potentials for practical applications in view of low cost and monolithic integration capability with a driving circuit.