http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Decreasing biotoxicity of fume particles produced in welding process
Yu, Kuei-Min,Topham, Nathan,Wang, Jun,Kalivoda, Mark,Tseng, Yiider,Wu, Chang-Yu,Lee, Wen-Jhy,Cho, Kuk Elsevier 2011 Journal of hazardous materials Vol.185 No.2
<P><B>Abstract</B></P><P>Welding fumes contain heavy metals, such as chromium, manganese, and nickel, which cause respiratory diseases and cancer. In this study, a SiO<SUB>2</SUB> precursor was evaluated as an additive to the shielding gas in an arc welding process to reduce the biotoxicity caused by welding fume particles. Transmission electron micrographic images show that SiO<SUB>2</SUB> coats on the surface of welding fume particles and promotes particle agglomeration. Energy dispersive X-ray spectroscopy further shows that the relative amount of silicon in these SiO<SUB>2</SUB>-coated agglomerates is higher than in baseline agglomerates. In addition, <I>Escherichia coli</I> (<I>E. coli</I>) exposed to different concentrations of pure SiO<SUB>2</SUB> particles generated from the arc welding process exhibits similar responses, suggesting that SiO<SUB>2</SUB> does not contribute to welding fume particle toxicity. The trend of <I>E. coli</I> growth in different concentrations of baseline welding fume particle shows the most significant inhibition occurs in higher exposure concentrations. The 50% lethal logarithmic concentrations for <I>E. coli</I> in arc welding particles of baseline, 2%, and 4.2% SiO<SUB>2</SUB> precursor additives were 823, 1605, and 1800mg/L, respectively. Taken together, these results suggest that using SiO<SUB>2</SUB> precursors as an additive to arc welding shielding gas can effectively reduce the biotoxicity of welding fume.</P>
A Novel Three-Phase Voltage-Doubler Soft-Switching Active Filter
Maoh-Chin Jiang,Jing-Jhu Jhan,Kuei Wu-Chang,Huang-Kai Fu 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5
A novel three-phase voltage-doubler soft-switching active filter (VDSSAF) comprising four main switches and four auxiliary switches is proposed in this paper. All main switches in the proposed VBSSAF operate at zero-voltage-switching (ZVS) turn on, while the auxiliary switches operate at zero-current-switching (ZCS) turn off. The reduction in the number of switches can also increase the reliability, since the control circuits are thereby reduced to two sets. The proposed VBSSAF can compensate the current harmonics, improve the power factor and balance the unbalanced nonlinear load. Moreover, a critical value of the capacitor voltage magnitude on the DC side and a critical value of the reactor inductance on the AC side for successful harmonic current tracking are also derived for design applications. Some experimental results of the VBSSAF, rated 400 W and operated at 40 ㎑, are provided to demonstrate the performance.
A Novel Single-Phase Soft-Switching Unipolar PWM Inverter
Maoh-Chin Jiang,Wei-Shiang Wang,Huang-Kai Fu,Kuei Wu-Chang 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5
A novel single-phase soft-switching unipolar PWM inverter (SSUPI) using a simple auxiliary resonant unit is proposed. All main switches of high-frequency arm operate at zero-voltage-switching (ZVS) turn-on, while the auxiliary switches operate at zero-current-switching (ZCS) turn-off. All main switches of low-frequency arm operate at 60 ㎐ to greatly reduce switching losses. As a result, commutations of the main power devices occur with low losses. Consequently, higher efficiency is achieved. Moreover, a unipolar PWM scheme is used to reduce the output voltage harmonics. Some experimental results of the proposed SSUPI, rated 500 W and operated at 40 ㎑, are presented for demonstration.
The back contact modification in high-efficiency Cu₂ZnSn(S,Se)₄ solar cells by a thin MoO₃ layer
Septia KHOLIMATUSSADIAH,Cheng-Ying CHEN,Wei-Chao CHEN,Yi-Rung LIN,Shao-Hung LU,Meng-Chia HSIEH,Jan-Kai CHANG,Chih-I WU,Ruei-San CHEN,Kuei-Hsien CHEN,Li-Chyong CHEN 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8