This thesis presented the design and construction of an adaptive active band-pass filter by using a tachometer circuit. The main part was the multi voltage-mode filter circuit based on an operational transconductance amplifier which could automatically adjust the center frequency to adapt to the input signal frequency by the tachometer circuit. The frequency error value in the center frequency was set to be ≤ 3% of the input signal. Furthermore the proposed filter could support the input signal in the frequency range of 10 Hz - 10 kHz. From the simulation and experimental results of the proposed prototype filter it could respond to the frequency according to the theory of the band-pass filter and the error in choosing the center frequency which was 1.45 % and 2.6 % respectively (below the set error value of 3 %). Therefore the proposed filter could be used for real application. The working principles of the proposed prototype filter could also be applied to the noise attenuation circuit of an electrocardiogram machine. Moreover this research could be used as a guideline study for those who want to develop other types of adaptive active filters for higher efficiency.

This study was conducted to determine the effects of plant growth regulators on in vitro propagated plantlets and microrhizome inductions of Curcuma comosa Roxb. for an efficient development of plant regeneration. In vitro sprouted shoots (2 cm length) of C. comosa were incised in longitudinal section and subcultured on MS media supplemented with 3 mg/L BA for shoot multiplication and plant regeneration. Subsequently the regenerated plants were transferred to MS medium with various concentrations of plant growth regulators; BA (1 3 5 mg/L) kinetin (1 3 5 mg/L) and TDZ (0.5 1 1.5 mg/L). The result showed that MS medium supplemented with 3 mg/L BA was the most effective in shoot induction with the significantly maximum average number of 2.11 shoot buds per responding explant. Moreover MS medium supplemented with 1 mg/L BA produced the longest average of shoot bud explants (12.99 cm) while the basal MS medium induced the longest average of root multiplication (6.63 cm). Furthermore microrhizome induction was produced under in vitro conditions derived young shoot buds upon transfer to MS medium containing various combinations of 1 3 and 5 mg/L BA and 30 60 and 90 g/L sucrose concentrations. The optimum combination in the induction of significantly highest average length of both stem (18.32 cm) and root (7.52 cm) multiplication was obtained on MS basal medium supplemented with 1 mg/L BA and 30 g/L sucrose for 4 weeks. Although microrhizome formation was not produced by the different amount of BA and sucrose in induction medium starch accumulation was found at the base of the stem explants cultured on MS medium containing 60 and 90 g/L sucrose concentrations. Additionally in vitro propagated C. comosa plantlets through microrhizome induction were grown under greenhouse conditions for 4 weeks and further developed into normal plants resulting in successfully high survival rates of 66 – 100% in the cultivated C. comosa.

The research aims to investigate the possibilities of crushed oyster shell (OS) not have to go through the process of burning as a substitution cement for concrete blocks. The cement was replaced with crushed oyster shell not process burning (OS) at 0% 10203040 and 50% by the weight of the binder. After that the concrete blocks were tested to determine the compressive strength and moisture absorbed of the concrete blocks cured for 7 142856 and 90 days The result showed that the compressive strength of the concrete blocks which replaced cement with OS (at the proportion of 10% by the weight of the binder) at 28 days had the compressive strength and water absorbed accordance with the TIS 58-2533 on non-load bearing concrete blocks.Moreover the concrete blocks which replaced cement with OS at the proportion of 20 % and 30 % had the compressive strength equivalent to 28 days compressive strength of TIS 58-2533 standard at 56 and 90 days respectively and decreased when the percentage in addition to OS in concrete blocks of 40 and 50 %. Tested results also showed that the water absorbed of concrete blocks increased when the percentage of replacement of OS in binder increased at 10 20 30 40 and 50%. The economical of concrete blocks it has manufactured unit cost is 2.60 baht. Whereas the concrete block containing crushed oyster shell at 10-30% it has manufactured unit cost at 2.12-2.44 baht respectively.

The objective of this research was to evaluate the antioxidant and glucosidase inhibitory activities of 9 fresh and dried local vegetables extract from Kong Ra District Phatthalung Province such as Barringtonia acutangula (L.) Gaertn. Archidendron jirinaga Nielsen Scientific name: in process (Neang-rok: local name) Oroxylum indicum (L.) Kurz Ficus semicordata J.E.Smith Ficus oligodon Mig Ficus sp. Ficus obpyramidata King and Ficus fistulosa Reinw. The antioxidant activities were determined by DPPH radical scavenging. Results indicated that dried crude extract of Oroxylum indicum (L.) Kurz exhibited the highest DPPH radical scavenging activity at the final concentration of 5 mg/ml revealed the DPPH activity as 92.25%. Moreover the extracts were studied for their glucosidase inhibitory activities compare with authentic drug Acarbose Results indicated that dried crude extract of Ficus sp. exhibited the highest inhibitory activity revealed the inhibition activity as 85.46%. Thus these local vegetable might be possible new sources of glucosidase inhibition and antioxidants so there are suitable for use as functional food in the future.

The objective of this research is to study the suitable factor level for the improvement of annealing furnace for rolled coils steel sheet. The experimenting has been performed to find suitable oxygen level by 5 annealing furnace experiment. The research has been started by collection the combustion. After that the burning adjustment by changing combustion technology with 5 levels of BGCV control valve open as 23% 40% 50% 75% and 100% has been implemented. The combustion adjustment data are recorded analyzed and compared with incomplete combustion value. The research result has been found that after improvement the combustion value. The percentage of oxygen level are improved to the better quality which standard at MV0-49% equal 2.5-4 O2% and MV50-100% equal 1.5-2.5 O2% conclusion 1 furnace as follows at the MV23.1% MV40% MV50% MV75% and MV100% level of oxygen as 2.5% 3% 3% 2% 1.5% and level of carbon monoxide as 0 ppm 2 ppm 2 ppm 2 ppm and 0 ppm respectively. Resulting of fuel energy consumption in the annealing process has been reduced around 225608 baht /year/furnace. Therefore it can depict that energy saving and annealing furnace efficiency improving are increased. The modified parameters will be applied to be the new standard reference values for the further engineer’s operational manual.