Entity

Time filter

Source Type

Taoyuan, Taiwan

Peng D.-X.,Army Academy
Industrial Lubrication and Tribology | Year: 2014

Purpose-Chemical mechanical polishing (CMP) has attracted much attention recently because of its importance as a nano-scale finishing process for high value-added large components that are used in the aerospace industry. The paper aims to discuss these issues. Design/methodology/approach-The characteristics of aluminum nanoparticles slurry including oxidizer, oxidizer contents, abrasive contents, slurry flow rate, and polishing time on aluminum nanoparticles CMP performance, including material removal amount and surface morphology were studied. Findings-Experimental results indicate that the CMP performance depends strongly on the oxidizer, oxidizer contents, and abrasive contents. Surface polished by slurries that contain nano-Al abrasives had a lower surface average roughness (Ra), lower topographical variations and less scratching. The material removal amount and the Ra were 124 and 7.61 nm with appropriate values of the process parameters of the oxidizer, oxidizer content, abrasive content, slurry flow rate and polishing time which were H2O2, 2 wt.%, 1 wt.%, 10 ml/min, 5 min, respectively. Originality/value-Based on SEM determinations of the process parameters for the polishing of the surfaces, the CMP mechanism was deduced preliminarily. © Emerald Group Publishing Limited. Source


Huang Y.-S.,Chung Cheng Institute of Technology | Sung C.-C.,Chung Cheng Institute of Technology | Sung C.-C.,Army Academy
IEEE Transactions on Industrial Electronics | Year: 2010

This paper presents a new methodology for designing and implementing position control for permanent-magnet linear synchronous motor (PMLSM) systems. We utilize both a new function-based sliding-mode control (SMC) method and direct thrust control (DTC). It has been established that chattering is a problem in conventional SMC and stems from discontinuous control. However, the new function-based controller allows designers to employ fuzzy membership functions directly. The advantage of the proposed method is that the chattering phenomenon can be reduced and/or completely eliminated. The design of the control method for the proposed system can be performed without the need for great expertise as it does not require the use of very complicated techniques. It should be noted that we have managed to control the inherent flux linkage problems associated with PMLSMs. To our knowledge, this is the first work that combines the new SMC with DTC techniques in order to create a position control for a real-world PMLSM. Simulation and experimental results verify that the proposed method can achieve favorable control performance with regard to parameter variations and external disturbances. © 2006 IEEE. Source


Hsu N.-F.,Army Academy | Chang M.,Chung Yuan Christian University
Materials Chemistry and Physics | Year: 2012

This work presents a rapid and simple synthesis procedure for ZnO nanowires (NWs) array by using the vapor-solid (VS) method. Experimental results indicate that the length and diameter of the grown ZnO NWs are associated with the temperature effect, while the growth density of NWs is strongly related to gas flux during the VS process. Additionally, the synthesized ZnO NWs possess specific crystalline qualities, making them highly promising for piezoelectric device applications. Therefore a piezoelectric type nanogenerator based on the ZnO NWs is also designed in this work, with a high output of piezoelectric current of 0.6 μA cm -2 obtained as well. Our results further demonstrate the feasibility of applying piezoelectric energy via the rapidly grown ZnO NWs array. © 2012 Elsevier B.V. All rights reserved. Source


Liao C.-C.,Army Academy | Liao C.-C.,Chung Yuan Christian University | Chung T.-W.,Chung Yuan Christian University
Chemical Engineering Research and Design | Year: 2013

A transesterification reaction of Jatropha curcas oil with methanol in the presence of KOH impregnated CaO catalyst was performed in a simple continuous process. The process variables such as methanol/oil molar ratio (X1), amount of catalyst (X2) and total reaction time (X3) were optimized through response surface methodology, using the Box-Behnken model. Within the range of the selected operating conditions, the optimal ratio of methanol to oil, amount of catalyst and total reaction time were found to be 8.42, 3.17% and 67.9min, respectively. The results showed that the amount of catalyst and total reaction time have significant effects on the transesterification reaction. For the product to be accepted as a biodiesel fuel, its purity must be above 96.5% of alkyl esters. Based on the optimum condition, the predicted biodiesel conversion was 97.6% while the actual experimental value was 97.1%. The above mentioned results demonstrated that the response surface methodology (RSM) based on Box-Behnken model can well predict the optimum condition for the biodiesel production. © 2013 The Institution of Chemical Engineers. Source


Sogut Z.,Army Academy | Oktay Z.,Balikesir University | Karakoc H.,Anadolu University
Applied Thermal Engineering | Year: 2010

In this study, heat recovery from rotary kiln was examined for a cement plant in Turkey. At first, an exergy analysis was carried out on the operational data of the plant. Results indicated the presence of 217.31 GJ of waste heat, which is 51% of the overall heat of the process. Then a mathematical model was developed for a new heat recovery exchanger for the plant. It was determined that 5% of the waste heat can be utilized with the heat recovery exchanger. The useful heat obtained is expected to partially satisfy the thermal loads of 678 dwellings in the vicinity through a new district heating system. This system is expected to decrease domestic-coal and natural gas consumption by 51.55% and 62.62% respectively. CO2 emissions may also be reduced by 5901.94 kg/h and 1816.90 kg/h when waste heat is used instead of coal and natural gas. © 2009 Elsevier Ltd. All rights reserved. Source

Discover hidden collaborations