Abstract: Refractive index and Abbe number are major physical properties of optical materials including glasses and transparent polymers. Refractive index is, in fact, not a constant number and is varied as a function of optical wavelength. The full refractive index spectrum can be obtained using a spectrometer. However, for optical component designers, three refractive indices at the wavelengths of 486.1 nm, 589.3 nm and 656.3 nm are usually sufficient for most of the design tasks, since the rest of the spectrum can be predicted by mathematical models and interpolation. In this paper, we propose a simple optical instrumental setup that determines the refractive indices at three wavelengths and the Abbe number of solid and liquid materials.
Abstract: Early detection of hazardous or flammable gasses/volatiles reduces the potential risks to personnel, such as development of respiratory problems. A simple robust resistive sensor device is presented with a sensing film of poly (styreneco-maleic acid) containing carbon nanotubes as the conductive medium. The response of the sensor was assessed with several volatile solvents and an industrial printer ink. All vapours were detected by increased resistance of the sensor film, and the ink vapour elicited the largest response. A warning system for volatile solvents could be based on this sensor design for use in industrial environments.
Abstract: This paper proposes a comparison between two methods of voltage regulation of over sending-end voltage in case of the load located near a substation. The first method is using tab change of power transformer and the other is the installation of voltage regulator in a factory. In the process, voltage level is completely measured before and after the installation of techniques, and is slightly decreased until it approaches to the lowest demand of loads, which can normally operate in the plant. The sequent test results show that the first method, sending-end voltage control via voltage regulator, can reduce squandered energy up to 8.3%, can also save energy up to 6.8% which is higher than the result of adjusting power transformer tap.
Abstract: The research purposes to design, analyze and build a report (MDR) integrity. To use as the MDR prototype in accordance with international standards for industrial factories. The MDR is important to the operator of equipment, the factories, and petrochemical industry because of it is an index for the quality assurance, quality control of fabrication and planning of maintenance management (material upgrade/ equipment change) for safety during equipment operation. When the equipment has a problem we can check for cause from the fabrication history data on MDR. A survey was developed for people concerned with the MDR, totaling 141 people from 58 factories in Thailand industrial sector for find out the demands and problems on using the MDR. The result shows that preparation of the MDR can cost more than a week of time, with no clear pattern of standard format and require manpower more than 3 peoples. In summary, the development of the MDR prototype by comparative data between, the manufacturer, the Ministry of Industry of Thailand and the American Society of Mechanical Engineers (ASME). The specialists who have the experience in the MDR to determine the completeness and validate all content in the MDR 15 chapters.
Abstract: This article presents theory of The design of medium sized voltage capacitor in order to improve the Power Factor Value to AC motor. In present, the electrical power system has focus on improving the Power Factor significantly because it is the major key to increase or decrease the applicable expenses. The power system that has low power factor will have a lot of loss to system, especially when electrical voltage is on voltage medium. When power factor has been adjusted, the system can take more loads and electrical power loss is decreased. It also decreases voltage in power line and decreases electrical bills at the same time. This article presents the theory to analyze data from motor that needs to adjust a power factor so that it pass electricity authority standard by considering the efficiency of the motor so that the consumers do not have to pay the penalty of the Power Factor Value differences to the Electricity Authority. Furthermore, it can help decrease the bills of unstandardized electrical power which occurred in the system and enable the system to take more loads at the same time.
Abstract: The beautiful colors of the rainbow have always fascinated humans and especially children are inspired to various artworks such as drawing, canvas painting, poster, wall decals and so on. Since refraction and reflection of light cannot be seen taking place in raindrop during rainbow formation, children are unaware of all these details. Although throughout the year past, there are many literatures on theoretical and mathematical aspects of rainbow formation, however there are very few studies in education context to teach about this phenomenon to the children in particular by observing and measuring. Therefore, in this paper we are proposing a model that can be used for hands-on learning with high school students about the formation of spectrum in glass sphere. With the help of the model students can see the angle at which different color lights are deviated by the glass sphere and finally, students can also relate the concept learnt from this lesson to real life phenomenon about spectrum formation by rain drop.
Abstract: Teaching of science is an endeavor to translate abstract scientific concepts into the concrete ones which can be accessed by students. Among others, one practical method is the use of a hands-on model that allows students to manipulate materials and examine targeted phenomena. In this study, a hands-on model called “seesaw balancing” was proposed to demonstrating effects of “moment of force” in a classroom. By using the seesaw balancing as the main part of a structured inquiry activity, a single group pretest-posttest research design was employed in this study. With the purposive sampling technique, 50 grade 9th students who have never experienced in topic of moment of force participated in the study. The paired-sample t-test indicated a significant enhancement of students’ conceptual understanding after the treatment of structured inquiry laboratory at .05 significant level. Moreover, attitude questionnaire reveals the students have positive view towards the hands-on model as they perceived the model is interesting, suitable with the level of the students, help them to do self-learning, and safe to handle, respectively.
Abstract: Recent advances in computer technology have led to the creation and development of computer-assisted instruction (CAI), which are rapidly assuming a prominent role in many fields of education. The development process includes analyzing lesson and users, designing computing lesson and assessment techniques, constructing computing lesson and assessment tools, and evaluating the lesson through users feedback. In this work, we aim to (i) Develop computer-assisted instruction of immune system organs and immune system diseases, and (ii) Examine efficiency of the developed CAI. A total of 142 secondary school students was involved in the study. Pretest-Posttest and Satisfaction questionnaire for the students towards the CAI were used as research instruments. The quantitative data was analyzed by t-test, and the qualitative data was analyzed by content analysis. The paired-sample t-test indicated a significant enhancement of students’ understanding after the using of developed instruction at .05 significant level. Moreover, the students were very satisfied with the developed CAI.
Abstract: We developed the interactive multimedia lesson for Michelson Interferometer experiment to compare learning achievement between students who learn with and without the interactive multimedia and to study student’s satisfaction of the interactive multimedia lesson. Michelson Interferometer experiment is the lesson in the Intermediate Physics Laboratory for the second year of Applied Physics students of the Rajamangala University of Technology Thanyaburi. In this experiment, students have to count numbers of light fringes to determine the wavelength of He-Ne laser. We also developed a light counting device providing better experiment results with only 0.032% error compared to counting only by eyes. The efficiency of the interactive multimedia lesson evaluated by 3 experts both in content and production technique of the courseware was 4.45 meaning that the developed the Interactive Multimedia lesson was qualified at a good level. The Interactive Multimedia had the effectiveness at 92.12:80.38 which was higher than standard criteria set (80:80). The post-test scores of students who studied with interactive multimedia were significantly higher than the pre-test score at .05 level, and the student’s satisfaction of the interactive multimedia lesson was 4.25 which students most preferred the Interactive Multimedia Michelson interferometer experiment at a good level.
Abstract: Sound wave cannot be seen. It is difficult to measure the speed of sound wave directly. The purpose of this study was to design and develop an educational experiment setup for measuring the speed of sound in air at a fixed pressure by the resonance method, which a surface of water will be used in reflecting sound wave from a function generator to produce resonance, which will be detected by human ear. In this study, wavelength of sound in air tube of pipe was adjusted by changing of water level. The water level was controlled with submersible pump and the gravity. The experimental data were statistically analysed by means and percentage errors. The range of percentage errors compared between the experimental value on 5 different frequencies and the theoretical value of the speed of sound is 0.07 to 0.32. This finding indicates that this experiment setup’s efficiency is adequate for demonstration that the speed of sound in air can be measured by the resonance method and the sound wave with different frequencies travel at the same speed. Measurement of the speed of sound can be performed accurately and easily even though its production cost was so low with using the least experimental tools.