The aim of this work was to validate the sample preparation using a microwave digestion for determination of total arsenic in a spiked soil. Graphite fernace atomic absorbtion spectrophotometer (GFAAS) technique was used to determine the total arsenic using palladium nitrate Pd(NO3)3 as a modifier agent. The instrumental detection was performed under the condition steps of drying ashing atomizing and cleaning to be 100 1200 2250 and 2600 C. The external calibration curve was constructed using the automatic program based on the master standard of arsenic with 20 ppb. It was found that linearity range was in the range of 1 to 20 ppb with R2>0.999. Based on microwave digestion condition the sample preparation with and without HF was also compared the total arsenic in the spiked soil with a 10 ppb. The result shoewd that the arsenic content obtained fron the prearation with and without HF did not significantly diferent at the 95% confidence limit. The recovery was 80.3 and 82.3% for the spiked sample with 2.5 and 10 ppb respectively. The relative standard deviation was 2.15% (n=11). The results of this work can also confirmed that the preparation method using microwave digestion provided the more advantages such as rapid a little volume of reagents completely digestion.

Thailand is an agricultural country. So that the water resources are important. The water management is very important for keep the water used in necessary time. The monsoon is causes a heavy rain. The monsoon prediction by the mathematical model is important. The accuracy of the forecasts by the predictability measurement method is very important. In this research improvement the predictability measurement for the winter monsoon prediction in the Southeast Asia by the shallow water model. The data from The Bjerknes Centre for Climate Research (BCCR) University of Bergen Norway. The global climate model is Bergen Climate Model (BCM) Version 2.0 (BCCR-BCM2.0) of the Intergovernmental Panel on Climate Change (IPCC) are used. The data for run the model on 19 December 2059 from the WCRP CMIP3 is the initial condition. The model is run for 7 days forecast. The Lyapunov exponent (LE) is the predictability measurement method for verify the efficiency of the model and improvement the largest Lyapunov exponent (LLE) by limit theorems for verify the efficiency of the model too. The results to show that the shallow water model can be prediction the winter monsoon for 4 days forecast is accuracy when compare with the BCCR-BCM2.0 model and measure the accuracy by LE. In addition the improvement the LLE by limit theorems can be measure the accuracy of the winter monsoon for 4 days forecast to same as the LE. Therefore the improvement the LLE by limit theorems can be measure the accuracy of the winter monsoon prediction in Thailand by the shallow water model are suitable.

The objectives of this research are to propose a model for estimating and detecting rice yields in Thailand to investigate the factors related to the rice yields to find the trend and to construct the maps of rice yields in Thailand. A linear mixed model (LMM) including the spatial effects which follow the conditional autoregressive model (CAR) and the time effects which follow the first-order linear autoregressive (AR(1)) model is proposed. The estimated rice yields are used to construct the rice yield maps in Thailand. The dependent variables are the rice yield in each month of each province. The factors considered are rainfall average temperatures and regions. The results indicate that the factors enfluencing the rice yields are rainfall average temperatures and regions (North Northeast South East West Central region is a refrence region). The trend also effects the rice yields. The rice yeilds maps are easy for readers to identify which areas have high or low yields and easy to compare the yields among areas by looking at their different colors.

The aim of this work was to fabrication of Hydroxyapatite Glass-ceramic by adding ZrO2 for Dental Application. The glasses were prepared by conventional melting of the coprecipitation derived starting products and heat treated at different temperatures. The structure mechanical properties and microstructure of the samples were characterized by X-ray diffraction Vicker hardness energy dispersive X-ray analysis (EDXA) and scanning electron microscopy. The data showed that the samples with condition Li1-1450 and heated treatment at 830 C having high strength and proper crystallinity showed good translucency which comparable with that of the sample from factory. XRD analysis revealed XRD analysis revealed that the peak corresponds to the crystallization of Li2SiO3 SiO2or Li6SiO8which are important phases have effect to increasing the mechanical properties of samples.

The research team has isolated the cellulase producing microorganisms which have capability in producing extracellular cellulase enzyme for cellulosic degradation from leftover agricultural waste materials such as fruits and vegetables. After cellulosic material degradation the products mainly were sugar moiety being the starting materials for further alcohol fermentation and/or possibly being used in cultivation of common microorganisms. In the study when different 49 bacterial isolates were tested for their cellulase activity on Carboxymethyl cellulose (CMC) two bacteria Bacillus spp. CE08 and 49 were selected due to high cellulase activity and thus tested for the physical and chemical properties. Their 16S rDNA sequence comparisons were close to Bacillus sp. isolate obtained from the soil. Both isolates are common aerobic/facultative aerobic bacteria with the length of 1-3 μm Gram positive and preferring the fermentation of maltose and xylose to glucose while minimal degradation on sucrose and lactose contents. Their optimum digestibility was at 40°C pH 4.5 for the broth having unpurified extracellular cellulase activity at 3-4 μg /mg. The enzyme could use the substrateCMC the best but rice straw more slowly but better than grass. However the enzyme displayed the least digestion effectiveness on cotton. Both of these isolates are expectedly applied in the biological degradation process substituting chemicals that cause pollution problems to the environment. Additionally this is one promise way to bring value of agricultural waste to the community.