• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.11
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• pp.1059-1064
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• 2001

This study Investigates the effect of the wave form of pulse energization on the collection characteristics of a wide plate spacing electrostatic precipitator. For the semi-pulse energization, the peak current and voltage of the energization increases with increase of the pulse period, and the corona current increases, as pulse ratio decreases. For the micro-pulse energization, the corona current increases with increase of the pulse voltage. The collection efficiency of semi-pulse and micro-pulse energization is larger than that of DC charge.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.1
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• pp.31-37
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• 2004

In this paper, the analysis result of the switching surge in substation including GIS(Gas Insulated Switchgear) has been described using the EMTP(Electro Magnetic Transient Program) program. After performing the modeling of the input data, we have reviewed the energization overvoltages of GCB(Gas Circuit Breaker) without closing resistor in 345kV network, according to the conditions of simultaneously operating switch and statistically operating switch. Firstly, it can be known that the energization overvoltage of single line is higher than that of parallel energized line. Secondly, the maximum energization overvoltage obtained in statistics switch is higher than one in simultaneous switch. From these results, it can be known that the phase-to-earth energization overvoltages of $\alpha$-$\beta$ section are less than 2.2 p.u when closing resistor is eliminated. Therefore, it is possible to consider the circuit breaker eliminated the closing resistor in $\alpha$-$\beta$ section.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.133-136
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• 1991

New phase-energization strategies are proposed to minimize torque ripple of closed-loop controlled 2-phase Bifilar Hybrid step motors. Lead angle and conduction angles are important parameters in minimizing torque ripple factors. The phase-energization control strategy that minimizes torque ripples for the given average torque is proposed. In this paper, Fourier series are applied to produce the average torque. The strategy is performed by controlling both lead angle and conduction angle of the input voltage wave-form for each phase.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.305-307
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• 1998

One of the merits of superconducting magnet system is that it has persistent current mode, in which the current can be constant without any external power supply. The problem is that when we energize the magnet we can not reach the target current with constant current source, in principle. It needs another energization methods, in which it can be energized with reasonable accuracy and time. This paper suggests two energization methods for a superconducting magnet with persistnet current mode and the comparisons of the two are made with respect to the accuracy and the time.

• The Bulletin of The Korean Astronomical Society
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• v.34 no.2
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• pp.25.1-25.1
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• 2009

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1482-1485
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• 2004

Electrostatic Precipitators have been used widely in industry, and play an important role in environmental protection. Electrostatic Precipitators (ESP) can be operated with a high collection efficiency and low pressure drop. Pulse energization is a technique to cope with high resistivity dust, and this results in lower power consumption. In this paper, Pulse energization ESP to use subway station air clean in subway station, design and test a pulse power supply for ESP.

• Safety and Health at Work
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• v.5 no.3
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• pp.158-160
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• 2014

Investigation and analysis of accidents are critical elements of safety management. The over-riding purpose of an organization in carrying out an accident investigation is to prevent similar accidents, as well as seek a general improvement in the management of health and safety. Hundreds of workers have suffered injuries while installing, maintaining, or servicing machinery and equipment due to sudden re-energization of power lines. This study presents and analyzes two electrical accidents (1 fatal injury and 1 serious injury) that occurred because the power supply was reconnected inadvertently or by mistake.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.04a
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• pp.157-158
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• 1999

• Journal of Microbiology and Biotechnology
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• v.13 no.1
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• pp.90-98
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• 2003

In vivo $^31p$ Nuclear Magnetic Resonance ($^31p$NMR) and metabolic studies were carried out on an acetic acid tolerant mutant, Zymomonas mobilis $ZM4/Ac^R$, and compared to those of the parent strain, Z. mobilis ZM4, to evaluate possible mechanisms of acetic acid resistance. This investigation was initiated to determine whether or not the mutant strain might be used as a suitable recombinant host far ethanol production from lignocellulose hydrolysates containing various inhibitory compounds. $ZM4/Ac^R$ showed multiple resistance to other lignocellulosic toxic compounds such as syringaldehyde, furfural, hydroxymethyl furfural, vanillin, and vanillic acid. The mutant strain was resistant to higher concentrations of ethanol or lower pH in the presence of sodium acetate, compared to ZM4 which showed more additive inhibition. in vivo $^31p$ NMR studies revealed that intracellular acidification and de-energization were two mechanisms by which acetic acid exerted its inhibitory effect. For $ZM4/Ac^R$, the internal pH and the energy status were less affected by sodium acetate compared to the parent strain. This resistance to pH change and de-energization caused by acetic acid is a possible explanation for the development of resistance by this strain.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.10
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• pp.908-913
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• 2004

This study investigates the effect of the wave form of pulse energization and dust concentration on the collection characteristics of a moving electrode electrostatic precipitator (MEEP). Under the same specific corona power, the collection efficiency of the MEEP for the lower dust concentration ($2g/m^3$) becomes higher than that for the higher concentration ($10g/m^3$). Both the collection efficiency and specific corona power increase with increasing pulse period for the same value of applied voltage. The collection efficiency of MEEP is higher than that of the conventional fixed plate electrode electrostatic precipitator.