The objectives of this research were the determination of sorption isotherms and the comparison of mathematical models to determine a suitable model in different temperature ranges for Khao Dawk Mali 105. This experiment was made by placing samples in containers which were contained saturated salt solutions to control the humidity in the ranges of 5.32 – 84.34 %RH and the hot air oven was used to provide temperature conditions at 25 and 70 oC. The samples were in containers until the mass of samples was constant so the equilibrium between the samples and the surrounding was reached and then the equilibrium moisture content was determined. The experiment found that for the same relative humidity in the air when the temperature increased the equilibrium moisture content would decrease and for the same temperature in the air when the relative humidity increased the equilibrium moisture content would increase. Furthermore the comparison of models by analysis from R-Squared (R2) and Chi-Square (χ2) in each temperature found that Henderson model was a suitable model at 25 oC and Chung & Pfost was a suitable model at 70 oC.

This research proposes an application of resistive and capacitive soil moisture sensors to investigate the influences of paddy temperature on the electrical signal received from sensors when tested with paddy moisture in the range 9.2 - 22.75%wb at 40 - 80ºC to determine the relationship between paddy moisture and electrical signals. It was found that the mean signal values between 20 - 40 seconds from both sensors were inversely linear correlation with the moisture content of the paddy. Temperature is the factors that influence the measured electrical signal. R2 Adjust R2 (95% confidence interval) and RMSEC showed that the model developed from the resistive sensor signals was accurate in calculating the moisture content of paddy between medium to high temperature in range 60 - 80ºC more than the low temperature range. While the capacitive sensor signals model is accurate in calculating paddy moisture between low to medium temperature in range 40 - 60 ºC. Therefore the resistive soil moisture sensor is possible and more suitable for applying as a paddy moisture sensor in the high temperature drying processes than a capacitor soil moisture sensor.

This research developed a new model to determine the moisture diffusion coefficient for the thin-layer paddy drying with the spouted free-fall bed dryer. The design and construction of the dryer was done to experiment with the drying kinetics. The experiment has studied under conditions of hot air temperature of 60-150 °C the initial paddy mass of 5 - 15 kg and hot air velocity of 19 m/s. The results showed that the higher hot air temperature and the lower initial paddy mass resulted in a significant reduction in drying time. The experimental results were used to calibrate 12 of the most popular thin-layer drying models to find a suitable one considering based on the root mean square error (RMSE) chi-squared value (χ2) and the correlation coefficient (r). It was found that the popular thin layer drying model was able to accurately predict the effect of the moisture ratio considering both the influence of hot air temperature and the initial paddy mass in linear models. The highest accuracy was RMSE = 0.0279 χ2 = 0.00084 and r = 0.9938. In addition the experimental results have been used to synthesize the new diffusion moisture coefficient which is a function of initial paddy mass temperature and drying time. This developed model was based on an exponential function with only 7 model constants. The simulated results observed that the new model achieved the average error only 1.8 percent compared with the best model that uses up to 24 model constants.

In order to maintain food and materials including drying products at the original dried condition silica gel can be one choice for absorbing moisture. Most silica gel is packed in an Parcel made from plastic which is difficult to naturally degrade thus causing environmental problems. This research therefore have developed packaging material from agricultural waste corn husks for absorbing moisture from food rice. From the study it was found that the corn husk paper had characteristic of smooth paper surface. When making it into a corn fiber Parcel its maximum moisture absorption from saturated humidity was 9.22±0.92% and it could absorb the moisture from the rice stored at room temperature when compared to the plastic sachet at 8.26±0.50% and 9.30±0.08% respectively. When coated with kaffir lime oil extract the corn husk Parcel had the capability in anti-fungus commonly habituated in corn husks up the concentration of 15000 ppm. It could naturally be degraded within 12 days. Therefore with these advantageous qualification the natural Parcel made of corn husk paper harboring silica is for moisture absorption as sustainable and environmental conservation material.

Nowadays Thailand is realizing the economic value of earthworms. Earthworm farming is a driving force that can stimulate the Thai economy. The objective of this project is to measure the humidity and temperature properties of the worms the two boards are circuit boards in microcontroller. These are the WeMos D1 ESP8266 board and NodeMCU ESP-32S board. The WeMos D1 ESP8266 board to measure the amount of water and temperature of of the soil and can turn the water supply on or off automatically. The NodeMCU ESP-32S board has a database system to collect real-time humidity and temperature data. The data is processed and displayed via a web interface. The experiment showed that in regard to earthworm farming the soil moisture alert system in the earthworm closet has a temperature accuracy of 28.5°C. The top soil has a humidity accuracy of 65% the middle soil has a humidity accuracy of 67% and the lower soil has a humidity accuracy of 67%. This allows the ideal moisture and humidity levels for the propagation of earthworms to be maintained. The alert system displays the temperature and humidity in the earthworm closet and can turn the water supply off if the soil moisture level gets too high for the worms - this can all be monitored via the web application. .