The objectives of this research are to propose a Bayesian model for spatial time series analysis to apply the proposed model to forecast a monthly rubber yield in Southern provinces of Thailand and to compare the performance of the proposed model with the classical Holt-Winters Additive Exponential smoothing. The proposed model is a linear mixed model (LMM) with spatial effects which follow a conditional autoregressive model (CAR). Dummy variables are used for seasonal effects. A Bayesian method is used for parameter estimation. The estimated monthly yields are used for the monthly rubber yield forecasting. The dependent variables are the rubber yield in each month of each province. The data are secondary data at a provincial level. The factors considered are spatial effects heterogeneity effects and seasonal effects. The results show that the factors influencing on the amount of rubber yields are spatial heterogeneity and seasonal effects. The proposed model is proper and forecast accurately. Using the mean absolute error (MAE) the proposed model has a better performance compared to the classical Holt-Winters Additive Exponential smoothing in both model fitting and model validating. The proposed model should be the first consideration for spatial time series forecasting.

This research aims to develop the Para-rubber floor tiles mixed with ethylene vinyl acetate plastic wastes (EVA plastics) from the factories. The study use Para-rubber STR 20 at 100 phr with various contents of EVA plastics (e.g. 0 5 10 20 40 and 80 phr) and then mixed with chemical substance at constant ratio include zinc oxide at 5 phr stearic acid at 2 phr sulfur at 3 phr mercaptobenzothiazole at 0.5 phr and diphenyl guanidine at 0.2 phr. The samples are ground by two-roll mill and formed by compression molding at 150 degree Celsius with 30x30x0.2 cm of dimension. The properties of the Para-rubber floor tiles are tested under ASTM standard. From the results it is found that the Para-rubber floor tiles mixed with 10 phr of EVA plastics is the suitable ratio for using as the rubber floor tiles and rubber wall tiles in building. This ratio can increase the hardness and wear resistant properties and decrease the density and thermal insulation properties when compare to the Para-rubber floor tiles without EVA plastic.

This research aims to study the properties of PMA asphalt shingle roof mixed withnatural latex by various contents of natural latex to PMA asphalt (e.g. 0.0 0.5 1.0 1.52.0 2.5 and 3.0 by weight). The heat pot was used to mix the mixture with lower than160 degree of Celsius. The PMA asphalt shingle roof mixed with natural latex sampleswere cast in 20 x 20 x 0.5 centimeter of dimension and added the fiber plate and stoneflake to reinforce and decorate the roof plate. The properties of the roof plates weretested under ASTM standard. From the results it is found that all samples can resist thetemperature higher than 200 degree of Celsius and the increasing of natural latex (lowerthan 1.5 of ratio) can improve the hardness property while the tensile strength andelongation properties are decreased. However when the amount of natural latexincreased to 2.0 of ratio the tensile strength are increased. After compare the PMA asphalt shingle roof mixed with natural latex (2.0 of ratio) and the general shingle roof found that the researched shingle roof can use as well as the general shingle roof and more tightly. The research results can develop to the PMA shingle roof products and replace the import shingle roofs.

Degumming process is a fundamental process for silk yam and silk fabric finishing. The main objective is scouring the substrate such as silk gum (sericin) wax and fatty acid from silk fiber. The principle of degumming process is destroying the peptide linkage of amino acid in sericin structure into a small molecule which is soluble in water. The hydrolysis reaction performed by acid alkaline enzyme surfactant as soap and high pressure steam process. The conventional methods favor degumming with soap and sodium carbonate. This process has a problem on the surface area of silk. Proteolytic enzymes can answer this problem but it seldom use because of a specific condition and high cost. For this reason the insteading of papain enzyme from dry latex of Carica payapa Linn. was decided to use for silk degumming at any condition study. This research was concerned with the silk degumming using papain enzyme form dry latex of Carica payapa Linn. The degumming process was performed at the temperature vary from 55 -85 degree Celsius time fromlO to 40 minutes and the amount of dry latex ranging from 0 to 4% owf in order to study the suitable condition for degumming and surface morphology. The efficiency of degumming process was evaluated by determination of tensile strength and stainiqgJest with dire~~ dyes (C.1. Direct Red 80~StaIDing result.will be opposed to degumming efficiency. The result was revealed; the appropriate conditions for silk degumming with dry Carica payapa Linn. s latex were recommended as follows : the amount of dry latex solution of 4 % owf at 75 degree Celsius for 30 minutes. The degummed fibers leaves lustrous soft and surface smooth. This condition does not have effect to tensile strength and fiber surface.

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.