Papers by Author: Min Jou

Abstract: Zinc stannate Zn2SnO4 (ZTO) nanoparticles were synthesized via a hydrothermal process utilizing sodium carbonate (Na2CO3) as a weak basic mineralizer. The samples were hydrothermally treated at 150, 200, and 250oC for 48 h. The X-ray diffraction (XRD) patterns show that the highly-crystalline ZTO nanostructure could be formed in a well-dispersed manner for the 250°C sample at a particle size of less than 50 nm. As determined from transmission electron microscopy (TEM) results, ZTO nanoparticles are face-centered cubic single crystals agglomerated together. The Raman spectra results showed that the ZTO nanocrystals have a spinel structure. Furthermore, photocatalytic activity was tested with methylene blue (MB) by UV irradiation. The ZTO synthesized by the 2 M Na2CO3 mineralizer at 250oC demonstrated excellent photocatalytic activity. The ZTO treated three different ways had three distinct UV-Visible absorption curves, which directly influences their corresponding photocatalytic activity.

Abstract: This paper discusses the magnetic drag force resulting from the relative motion of a permanent magnet moving along a finite dimensional conducting plate. The image method with imaginary eddy currents is investigated. Boundary conditions are established to ensure that the eddy currents vanished at the boundaries of the conducting plate. Magnetic drag force is computed based on the eddy current distributions using Lorentz force law. A test system is built to demonstrate the magnetic brakes arose from the electromagnetic interactions.

Abstract: Manufacturing engineering education is science & technology based subjects that are traditionally the hardest to teach online because of the need for providing practice & hands-on experiences at a distance. Therefore, this research aims to develop an e-learning system to teach manufacturing technology and to enhance the quality, scale, and breadth of technological education. The major results of this research are; (1).Establish interactive on-line teaching material for the computer-aided manufacturing courses including CNC coding method, CNC simulation. (2).Propose the interactive teaching strategies for the students to learn machining process planning through web-based learning system. (3).Integrate multi-media and virtual laboratory in the developed interactive e-learning system to enhance the effectiveness of machining education through web-based system. (4). Enhance students the ability to extract the manufacturing features from a mechanical drawing in either 2D or 3D. (5). Cultivate the principle of manufacturing process planning through the developed interactive web-based learning system. (6). Discipline CNC programming and CNC machining techniques through Internet.

Abstract: Coating technologies are widely used in manufacturing processes, to prevent products from deterioration due to the actions of water, air, or an acid, to improve the artistic functions of product. In advance of nano-technologies, the geometry of coating particles will be fabricated as designed. Therefore, the effects of the geometry of materials on the coating quality should be considered in manufacturing processes. Surface roughness is one of the major indicators of coating quality. The correlation of geometry of coating materials and surface roughness on the performance of coated electrodes is presented in this paper. Three types of geometries are analyzed which are spherical particles, uniformly distributed columns, and random types. Besides the geometry of coating materials, the impact force resulting from spray jet will alter the surface roughness and is one of the important factors to coating quality. Therefore, the stability of coating jet is also studied. The findings show that high frequency waves can be added into the flow to get neutrally stable condition which will improve the stability of impact force.