The objective of this research is to develop a small and low-cost weather station. The station will be wireless transmit and receive data via radio signals. The 45mW solar cell will be used as a solar irradiance sensor which is very expensive for the weather station and the PIC18F97J60 controller will control the transmitter and receiver system. Moreover the author has developed the weather monitoring software by using LabVIEW. After testing the measurement percentage errors with the reference weather station the results showed that the relative humidity measurement error is equal to 3.106% the temperature measurement error is equal to 0.685% the wind speed is about 4.527% the wind direction measurement error is equal to 5.236% and the solar irradiance measurement error is equal to 0.501%. The longest working distance between the weather sensor and receiver unit is equal to 145 meters.

This research aimed to determine the optimal sand mold mixture’s ratio by using return sand bentonite water content and new sand component. Then the properties of the mixture according to the standards of American Foundrymen’s Society include the ability of compactability moisture content permeability and green compressive strength. This study applied mixture experiments and response surface methodology to determine an optimal sand mold mixture components condition. After the experiment and linear programming it indicated that the condition was at return sand (95.5387 %) bentonite (1.130102 %) water content (2.331196 %) and new sand (1 %). The green sand mold has compactability (58.37923 %) permeability (73.80148 %) moisture 6.5 % and green compressive strength (0.53 Kg/cm2). At this condition the cost is 11.31579 baths per kilogram.

Thesis is the development of radio-controlled lawn mower which can move and cut the grass in the desired environment and dangerous to human. The objective is to develop a radio-controlled lawn mower. The results showed that the rate of fuel consumption of controlled lawn mower in to cutting grass. The height of the grass at 6 8 and 10 cm. It has the average fuel consumption is 113 117 and 123 ml. The average time in the mowing is 6.6 8.01 and 9.69 minutes

This paper presents a study of heat exchanger design for improving the performance of ice maker by using waste water from ice factory. The heat exchanger was made of stainless steel and had 4.023 m2 of heating surface. After using the heat exchange in the waste water pond which the temperature was 0 C the temperature of feed water was decreased from 28 C to 22 C. The COP of the ice maker was increased and the factory can save energy consumption 52034 kWh/year or 61993 baht/year. The payback period was 0.5 year

In this paper the printed loop antenna is proposed for high frequency radio frequency identification (HF-RFID) systems (13.56 MHz). The proposed antenna is designed on the printed circuit board (PCB). The antenna structure consists of printed semi-spiral loop with rectangular structure patch at the middle of loop. It can provide the magnetic field distribution to cover the operating area with various directions that can improve the communication performance between reader and various tag orientations. From the measured results the proposed antenna has more efficient than the printed spiral loop antenna