Ming Der Jean

Evaluation of Light Irradiation on Decolorization of Azo Dyes by Tsukamurella sp. J8025

In the previous study, the dye decolorization was investigated by Tsukamurella sp. J8025 under the static condition at 30°C. The object of this study was to evaluate the influence of light irradiation with 15W low-pressure mercury lamp on dye decolorization. Three kinds of common culture medium Luria-Bertani (LB), Tryptic Soy Broth (TSB), and Yeast extract-Malt Extract (YEME) were used in this study. Strain J8025 was cultivated in different media added with methyl orange, and the rate of color removal was determined by measuring the absorbance at specific wavelengths. The experiments proved the decolorization efficiency after 48h under light irradiation in LB medium was up to 40%, that in TSB medium was up to 50%, and that in YEME medium was up to 68%, respectively. The decolorization process needed glucose as an energy source to support the bacterial growth and promote the decolorization rate. Due to the salt contained in the dye-wastewater, the effect of salt was investigated. The results showed nearly 98% color was removed after 48 h in the presence of 1% NaCl under light irradiation, but the decolorization was inhibited by high concentrations of salt. The results indicated a strain J8025 coupling with the light irradiation could be potentially used to improve the dye decolorization.

Improving the Performance of HVOF Sprayed WC-Co Coatings Using Statistical Design

This study reports the statistical optimization of experiments, designed by Taguchi, to improve the wear-resistance of the tungsten carbide/cobalt-based coatings applied using high-velocity oxygen-fuel (HVOF) spraying processes. In this study, a group of needlelike textures appeared in the HVOF WC-Co coatings. The structures were evenly distributed and compacted closely, showing a more dense and homogenous configuration. The coating that formed with a large amount of pores, microcracks and unmolten particles was much looser, and the interface was locally prone to defects. The coatings were obviously not homogenous. Experimental results show that the wear-resistant coatings are highly dense, with an elastic lamellar structure. The tribological properties were significantly improved and the surface textures showed uniformity, in a molten droplet flattened formation. A homogenous, morphological structure, with local small aggregation, was more obvious after HVOF WC-Co coating. Accordingly, it is clear that the surface properties determined proved favorable to the mechanical properties of the WC/Co coatings. In addition, we compared the linear models with the quadric models, using RSM methods, in all the experiments. Statistically, the linear models produced an average error of 8.285％, while the quadric models generated an average error of 1.399％. It is clear that the RSM models successfully fitted the HVOF WC-Co coating process and the quadric models yielded more accurate predictions than the linear models, in most cases. The proposed procedure was applied to HVOF spraying of WC-CO coatings. The results demonstrated its feasibility and its effectiveness in improving the HVOF WC-Co coating.

On the Hardfacing Performance Optimization after Plasma Transfer Arc Experiments

The paper describes response surface methodology (RSM) based on design of experiments and analysis of variance (ANOVA) as a statistical design while developing a robust plasma transfer arc (PTA)coating process. Based on ANOVA, The relative important parameters with respect to surface at hardness values were identified in the Taguchi design, where they were further used in predictors. In addition, we applied three-dimensional graphs in RSM to develop a robust PTA response surface yielding the desired-better area of a treated layer. In this study, a quadratic polynomial with a Box-Behnken design is utilized. The results reveal that RSM provides the effective methods as compared to the traditional trial-and-error method for exploring the effects of controlled factors on response. A very good agreement was observed, as evidenced by R-squared value, 90%, between the predicted and the experimental data, and its error percent is found to be approximately 3.801% in the PTA-coating process. It is clear that RSM model demonstrated better accuracy in predicting surface hardness for PTA-coating process. Accordingly, RSM based on design of experiments was used as statistical PTA-coating design tools combined with the hardness model. Device zone optimization and yield enhancement have been demonstrated.

Analysis of Surface Properties of Diamond-Like Carbon Films by a Sputtering Deposition

A new approach with adaptive network-based fuzzy inference systems (ANFIS) based on experimental designs was used to model and characterize the tribological behaviors of diamond-like carbon (DLC) films deposited by a magnetron sputtering system. An orthogonal array experiment was introduced and the effects of deposited parameters on the films were systematically explored. The films were analyzed by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). In this study, a group of highly developed hillock-like textures appeared and a lower wear volume loss became visible in the DLC films. Furthermore, the predicted values and experimental results, in which the ANFIS effectively predicts the tribological behaviors of the DLC films, are similar. It was experimentally confirmed the ANFIS predictions agreed with the experiments. Therefore, the experimental results demonstrate the tribological properties on DLC multilayer films are accurately predicted by ANFIS, thereby justifying the reliability and feasibility of the approach.

Desirability-Based Performance Optimization of Wear-Resistant Coatings by HVOF Sprayed WC-Co Experiments

This study presented the desirability function based on Taguchi designed experiments to solve multiple responses statistical optimal problems for the tungsten carbide/cobalt (WC-Co) coatings of high-velocity-oxygen-fuel (HVOF) processes. The eight control factors based on L18 arrays were conducted and the multi-responses of wear-resistant coatings such as hardness, deposited thickness and wear rate were evaluated simultaneously in the desirability-based experiments. Based on desirability analysis, the optimal settings have been identified, and the impacts of control factors are determined by analysis of variance on the multi-responses. Further, a confirmation run was conducted to validate the tests. Experimental results have shown that the hardness increased by 16.61% and the deposited thickness improved by 10.50%, while the wear rate decreased by 34.03%. It was clear that confirmation tests are greatly improved by way of the desirability-based multi-responses on HVOF WC-Co experiments, and these findings achieved the desired values on wear-resistant coatings. The proposed procedure was applied at HVOF sprayed WC-Co experiments, and the implementation results demonstrated its feasibility and effectiveness to maximize hardness, make a target of deposited thickness value and minimize wear rate by a HVOF.

Application of Micro-Tube Water-Cooling Device for the Improvement of Heat Management in Mixed White Light Emitting Diode Modules

This paper introduces a module using the RGB-based LED design to improve the thermal management of a mixied white light LED and describes a system for heat dissipation in illuminated, high-power LED arrays. Mixed light LEDs can be produced by combining appropriate amounts of light from the red, green and blue LEDs in an array. A LED cooling system, using a micro- tube water-cooling device, was fabricated. Recycling water in the system, gave more efficient convection and the heat created by the LEDs was easily removed, in the experiments. It was shown that micro-tube water-cooling systems rendered an improvement in thermal management that effectively decreases the thermal resistance and provides very good thermal dissipation. Furthermore, the results of experiment and simulation demonstrated that a micro-tube water-cooling system is very effective in heat dissipation in LEDs and the fabrication of practical micro-water tube cooling devices for mixing light LEDs was feasible and useful

Structural Properties, Modeling and Optimization of Tribological Behaviors of Plasma Sprayed Ceramic Coatings

This study used Taguchi plasma-sprayed experiments to determine the surface wear-resistant performance optimization of yttria partially stabilized zirconia (ZrO2/8Y2O3) coatings. Eight control factors based on L18 arrays were conducted and the wear-resistant properties of coatings were evaluated in the experiments. Based on analysis of variance, the optimal settings have been identified, and response surface methodology is utilized. Further, the contour nature of the quadric function is conducted to validate the tests in the Taguchi designed experiments. The experimental results obtained show that using an experimental design strategy with the proposed quadric model is useful not only for predicted optimal process parameters to achieve a desired quality but also for process optimization. Several response plots were generated to examine parameter effects on the response profiles. In addition, microstructures of the worn surface were examined, revealing a dense texture and highly anisotropic properties in the coatings with high anti-wear behavior.

Optimization of Tensile Properties Based on Spin Tool Shoulder Geometry for Friction Stir Welded 6061 Aluminum Alloy

This study reported the statistical optimization based on Taguchi designed experiments to improve the tensile properties of 6061 Aluminum alloy by the friction stir welding (FSW) experiments. The morphology and the structure of the friction stir welded experiments were characterized by scanning electron microscopy. Based on analysis of variance, the impacts of control factors have been identified for the tensile strength of 6061 aluminum alloy by friction stir welding. Experimental results revealed that the defect free butt joints could be obtained by cylindrical-screw type of tool shoulder and the joints made with a cylindrical-screw type resulted in better tensile properties compared to the other two shoulder geometries. Furthermore, it was clear that the tensile properties are greatly improved by friction stir welded experiments in the Taguchi design, and these findings have achieved the desired values in regard to the friction stir welded Experiments. The proposed procedure was applied at friction stir welded experiments, and the implementation results demonstrated its feasibility and effectiveness to enhance the tensile properties by FSW .

Study of Magnetic Fields of Magnetron Sputtering Affecting CrN Films

This article presents the distribution of the varying magnetic field and its effect by magnetron sputtering on mechanical properties of CrN films. The magnetic field variations in the sputtering processes were explored, and the strength of magnetic field in the unbalanced magnetic sputtering systems is controlled. In addition, the microstructure, composition and surface properties of CrN films prepared by magnetron sputtering were investigated. At a GDMT of 27mm, the highest wear rate value and hardness values seems to be appeared, while the higher critical force value appears to occur at 49mm GDMT during 18 tests. The experimental results have showed that in the enhancement in overall intensity at the gap distance of 27mm between magnet set and the target surface (GDMT), magnetic field strength varied having a significant influence on the CrN structures was readily noticeable, while the wear scar curve at 49mm GDMT possessed better tribological properties than those of the others. Thus, magnetic field variations play a crucial role in determining the properties of the films

Design and Optimization of Surface Properties for Diamond-Like Carbon Films by Sputtering Depositions

Analysis of mechanical properties of diamond-like carbon (DLC) films based on experimental designs was reported to optimize characterize by a magnetron sputtering. An orthogonal array experiment was introduced and the effects of deposited parameters on the films were systematically explored. The films were analyzed by scanning electron microscopy (SEM). Friction and wear tests were carried out using a pin-on-disk tribometer. In this study, the two stages such as adhesive and abrasive wears for tribological properties are clearly visible among L18 tests, where at the higher wear volume losses exist an abrasive wear while the less wear volume losses appear an adhesive wear. A slightly worn surface with a glassy carbon phase appeared and a lower wear volume loss became visible in the DLC films. Through the optimal design, the experimental results demonstrate the tribological properties on DLC multilayer films are increased by a magnetron sputtering, thereby justifying the reliability and feasibility of the approach.