• Journal of Power Electronics
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• 제15권5호
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• pp.1348-1357
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• 2015

Under traditional unified power quality conditioner (UPQC) control, a UPQC series converter (SC) is mainly used to handle grid-side power quality problems while its parallel converter (PC) is mainly used to handle load-side power quality problems. The SC and PC are relatively independent. The SC is usually in standby mode and it only runs when the grid voltage abruptly changes. In this paper, novel UPQC coordinated control strategies are proposed which use the SC to share the reactive power compensation function of the PC especially without grid-side power quality problems. However, in some cases, there will be a circulating current between the SC and the PC, which will probably influence the compensation fashion, the compensation capacity, or the normal work of the UPQC. Through an active power circulation analysis, strategies with and without a circulating current are presented which fuses the reactive power allocation strategy of the SC and the PC, the composite control strategy of the SC and the compensation strategy of the DC storage unit. Both of the strategies effectively solve the SC long term idle problem, limit the influence of the circulating current, optimize all of the UPQC units and reduce the production cost. An analysis, along with simulation andexperimental results, is presented to verify the feasibility and effectiveness of the proposed control strategies.

• BMB Reports
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• 제48권3호
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• pp.127-128
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• 2015

Tumor metastasis involves circulating and tumor-initiating capacities of metastatic cancer cells. Hepatic TM4SF5 promotes EMT for malignant growth and migration. Hepatocellular carcinoma (HCC) biomarkers remain unexplored for metastatic potential throughout metastasis. Here, novel TM4SF5/CD44 interaction-mediated self-renewal and circulating tumor cell (CTC) capacities were mechanistically explored. TM4SF5-dependent sphere growth was correlated with $CD133^+$, $CD24^-$, ALDH activity, and a physical association between CD44 and TM4SF5. The TM4SF5/CD44 interaction activated c-Src/STAT3/ Twist1/ B mi1 signaling for spheroid formation, while disturbing the interaction, expression, or activity of any component in this signaling pathway inhibited spheroid formation. In serial xenografts of less than 5,000 cells/injection, TM4SF5-positive tumors exhibited locally-increased CD44 expression, suggesting tumor cell differentiation. TM4SF5-positive cells were identified circulating in blood 4 to 6 weeks after orthotopic liver-injection. Anti-TM4SF reagents blocked their metastasis to distal intestinal organs. Altogether, our results provide evidence that TM4SF5 promotes self-renewal and CTC properties supported by $CD133^+/TM4SF5^+/CD44^+^{(TM4SF5-bound)}/ALDH^+/CD24^-$ markers during HCC metastasis.

• Journal of Electrical Engineering and Technology
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• 제2권3호
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• pp.320-328
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• 2007

The sheath in underground power cables serves as a layer to prevent moisture ingress into the insulation layer and provide a path for earth return current. Nowadays, owing to the maturity of manufacturing technologies, there are normally no problems for the quality of the sheath itself. However, after the cable is laid in the cable tunnel and is operating as part of the transmission network, due to network construction and some unexpected factors, some problems may be caused to the sheath. One of them is the high sheath circulating current. In a power cable system, the uniform configuration of the cables between sections is sometimes difficult to achieve because of the geometrical limitation. This will cause the increase of sheath circulating current, which results in the increase of sheath loss and the decrease of permissible current. This paper will study the various characteristics and effects of sheath circulating current, and then will prove why the sheath current rises on the underground power cable system. A newly designed device known as the Power Cable Current Analyser, as well as ATP simulation and calculation equation are used for this analysis.

• 자원리싸이클링
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• 제15권1호
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• pp.58-65
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• 2006

폐플라스틱과 건조 슬러지를 원료로 제조한 RDF (Refused Plastic Fuel)를 순환유동층 보일러에서 연소 하는 새로운 개념의 기술이 개발 중이다. 연소시험을 통해 RDF의 연소특성과 배연특성을 연구하여 설계 자료를 확보하였다. 연소성은 양호하였으며 중요한 공해물질인 HCl 발생은 150ppm 미만으로 나타났다. 기존의 석탄용 순환유동층 보일러와 RDF 전용 순환유동층 보일러의 차이점을 분석하고 순환유동층 RDF 전용 보일러 공정의 개념 설계를 수행하였다.

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2005년도 추계정기총회 및 제26회 학술발표대회 고분자리싸이클링기술 특별심포지엄
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• pp.124-134
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• 2005

폐플라스틱과 건조 슬러지를 원료로 제조한 RDF (Refused Plastic Fuel)를 순환유동층 보일러에서 연소 하는 새로운 개념의 기술이 개발 중이다. 연소시험을 통해 RDF의 연소특성과 배연특성을 연구하여 설계 자료를 확보하였다. 연소성은 양호하였으며 중요한 공해물질인 HCl 발생은 150ppm 미만으로 나타났다. 기존의 석탄용 순환유동층 보일러와 RDF 전용 순환유동층 보일러의 차이점을 분석하고 순환유동층 RDF 전용 보일러 공정의 개념 설계를 수행하였다.

• Biomolecules & Therapeutics
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• 제25권4호
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• pp.367-373
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• 2017

This study was performed to evaluate whether microRNAs (miRNAs) in circulating exosomes may serve as biomarkers of drug-induced liver, kidney, or muscle-injury. Quantitative PCR analyses were performed to measure the amounts of liver-specific miRNAs (miR-122, miR-192, and miR-155), kidney-specific miR-146a, or muscle-specific miR-206 in plasma and exosomes from mice treated with liver, kidney or muscle toxicants. The levels of liver-specific miRNAs in circulating plasma and exosomes were elevated in acetaminophen-induced liver injury and returned to basal levels by treatment with antioxidant N-acetyl-cysteine. Circulating miR-146a and miR-206 were increased in cisplatin-induced nephrotoxicity and bupivacaine-induced myotoxicity, respectively. Taken together, these results indicate that circulating plasma and exosomal miRNAs can be used as potential biomarkers specific for drug-induced liver, kidney or muscle injury.

• 한국연초학회지
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• 제14권1호
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• pp.48-56
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• 1992

This studies were carried out to investigate the effects of leaf loading quantity and circulating air volume during bulk curing on the variation of physical and chemical characteristics in flue-cured tobacco. The results are as follows : 1. The content of sugar in cured leaves was decreased with more circulating air volume and leaf loading quantity at bulk curing. 2. Total nitrogen and protein nitrogen were decreased with less circulating air volume and more leaf loading quantity, while amino nitrogen was increased. 3. The contents of linolenic acid and linoleic acid were increased with more leaf loading quantity and oxalic acid and citric acid had a tendency of being increased in case of high circulating air volume. 4. In general, major aromatic compounds were increased through flue-curing. Relatively high content of solanone in case of lower air volume and less leaf loading were observed, while megastig matrienone was increased when leaf loading was small. 5. The more circulation air volume with leaf loading quantity caused lowering equilibrium moisture content and higher shatter index, which resulted in poor quality of cured leaves based on quality index, nitrogen number, taste index phillips index, and sugar-nicotine ratio.

• 대한기계학회논문집B
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• 제37권11호
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• pp.1031-1036
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• 2013

종래의 모터 펌프를 이용한 매트용 온수보일러는 큰 유량을 공급할 수 있지만 모터 펌프의 진동과 소음이 큰 단점이 있다. 모터 펌프를 사용하지 않는 매트용 온수보일러의 경우 소음과 진동이 억제되는 장점이 있지만 감소된 유량으로 인해 매트의 온도 편차가 큰 단점이 있다. 본 연구에서는 기존 펌프 없는 온수보일러가 가지고 있는 문제점을 개선하여 순환유량을 증가시킨 새로운 온수 보일러 방식을 제안하고 실험을 통해 그 성능을 입증하였다. 성능 실험 결과 순환 유량의 증가로 매트 온도 상승시간이 대폭 줄어들었으며 유입 온수와 유출 온수의 온도 편차도 많이 줄어들어 종래의 펌프 없는 온수보일러와 비교하여 성능 개선을 입증하였다.

• 한국연초학회지
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• 제8권2호
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• pp.19-27
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• 1986

This experiment was carried out to investigate the effect of circulating air volume to chemical composition of tobacco leaves during the bulk curing. The results were as follows : The decrease of circulating air volume prolonged curing time as the case of a 0.058m3/min. kg; but, no remarkable changes with a 0.11m3/min. kg and a 0.083m3/min. kg. When the circulating air volume was decreased, compared with 0.11m3/min. kg, sugar content was increased while total nitrogen and nicotine content showed a reduced values. In case of a 0.058m3/min. kg and a 0.083m3/min.kg, solanone and damascenone were high. Some of volatile neutral constituents and volatile organic acids were increased during curing process ; especially, their quantities were remarkably increased during the midrib drying stage. As circulating air volume decreased the equilibrium moisture content was increased, while leaf shatter index and filling capacity were decreased.

• 전력전자학회논문지
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• 제24권2호
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• pp.71-77
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• 2019

This study proposes a circulating current reduction method that uses high-frequency voltage compensation when carrier phase difference occurs between two inverters in MSIS. In MSIS, inverters are configured in parallel to increase power capacity and to increase efficiency by using inverters only as needed. However, in the parallel inverter structure, circulating current is inevitably generated. Circulating current increases the stress on the switch, adversely affects the current control performance, and renders load sharing difficult. The proposed method compensates for the output voltage reference of the slave module by using the high-frequency voltage so that the switching pattern of each module is matched even in asynchronous carriers. The validity of the proposed method is verified by simulations and experiments with 600 W IPMSM.