In this study pH physical and microbiological qualities of clear and opaque plastic bottled drinking water produced in Buriram Province Thailand were investigated. Samples of bottled drinking water (N=22) were 8 clear plastic bottles and 14 opaque plastic bottles. Results showed that pH value of all samples were in a range of 6.04 ± 0.03 to 7.61 ± 0.01 in which 7 samples were not acceptable according to the criteria for drinking water in sealed containers declared by the Ministry of Public Health of Thailand. Coliform bacteria in all tested samples were less than 1.8 MPN/100mL and none of E. coli was detected. Therefore consumers of bottled drinking water produced from Buriram province should be aware of health safety because some drinking water products were unacceptable in terms of pH value.

This research aims to construct and evaluate efficiency of experiment set for work-piece analysis based on variety of cutting edge parameters of punch-die. The parameters included clearance punch shape and inclination of punch edge that related to cutting force error in diameter and deformation of work-piece. The developed experimental set was evaluated by 15 experts using 5-point scale questionnaire which was divided into two parts: content and worksheet and experiment set design. The efficiency evaluation was done by using the experiment set to teach a sample group of 15 students. Results showed that quality of the proposed experiment set was in the highest level with average score of 4.65 (SD = 0.47). The efficiency evaluation by teaching a sample student group revealed that the efficiency was 85.43/84.00 which was higher than the criteria of 80/80 in research hypothesis. Therefore it can be concluded that the constructed experiment set could be used to enhance students’ analytical thinking in punch-die work.

The objectives of this research are to construct and determine the quality and efficiency of a simple vibration experiment package. This experiment package design was based on free body diagram of content and main knowledge analyzed from behavioral objectives. Quality of the experiment package was assessed by 12 experts in 4 aspects which included theoretical sheet experimental sheet exercise sheet and experiment device design. The efficiency evaluation was performed by a sample group of 18 students. The exercise sheet was done by the students after finishing each teaching topic and examination sheet was done after finishing all teaching topics. Results showed that quality of the constructed simple vibration experiment package was in a high level of 4.8. Efficiency of the experiment package was 80.47/81.85 which was higher than specified in the research hypotheses. Therefore the experiment package could be applied to teach in any classroom with high students learning outcome.

There are three main purposes of this research. The first is to compare teachers ability in classifying content by students knowledge level before and after learning. The second is to study difference of pretest and posttest score according to students level. The third is to compare ability and determine efficiency in classifying content by duration of teaching experiences. Samples in this study were 30 teachers from Rajamangala University of Technology who leamed through CAI media (15 teachers) and who attended computer training course (15 teachers). The questionnaire was used to measure their ability in classifying content by students knowledge level. Results of the study can be concluded as follows: 1. Teachers ability in classifying content before and after leaming differed significantly at the level of 0.05. Howeverability in classifying content after leaming did not show significant statistical difference. 2. The difference in pretest and posttest scores showed that leaming with CAI could increase level of teachers ability in classifying more than attending training courses. 3. Teachers with different duration of teaching experience showed significant different ability in classifying content by students knowledge level at the level of 0.05. 4. Teachers with more than 7 years of teaching experiences showed the highest efficiency in classifying content.