고전압 대전류 송전에 적합한 절연관 부스바 소개

박병준,Park, Byeong-Jun 한국열병합발전협회 2011 열병합발전 Vol.80 No.-

고전압, 대전류의 송전을 위한 기존의 케이블 포설법과 부스덕트 시공법상 발생하기 쉬운 여러 문제점에 대한 보완 개선되어 새롭게 개발된 HiViPS (High Voltage/Current Insulation Pipe Bus-bar System)라는 복합 차폐 절연관 부스바(Complex Insulation Pipe Tubular Bus-bar)를 소개한다.

오픈소스 CFD 코드 $OpenFOAM^{(R)}$에 대한 소개와 사용법 상(上)

박병준,Park, Byeong-Jun 한국수자원학회 2011 물과 미래(한국수자원학회지) Vol.44 No.11

준설토 배송관로 내에서의 개질재 혼합효율에 대한 CFD 해석

박병준,강병윤,정민철,신재렬,Park, Byongjun,Kang, Byungyoon,Chung, Minchul,Shin, Jaeryul 대한토목학회 2015 대한토목학회논문집 Vol.35 No.5

본 연구는 준설매립과정에서의 관중혼합 거동을 3차원 전산유체역학(CFD, Computational Fluid Dynamics)을 통해 분석한 연구로 준설토 배송관과 개질재 주입관이 합류하며 발생되는 이상(2-phase)유체의 혼합효율을 사전 평가함으로써 관중혼합 양상을 고찰하는 물리실험의 시행착오를 줄여 경제성을 증진시키는데 연구목적을 두고 있다. 수치해석에 이용된 CFD 코드는 OpenFOAM$^{(R)}$이고, 몇 가지의 기본가정 하에 배송관-주입관의 관경과 합류각을 변화시켜 총 18가지 경우에 대한 삼상(3-phase)유체 거동을 모의하였다. 그 결과 혼합효율에 대한 우열은 있었으나 그 차이는 미미하였고, 모든 경우에서 각 재료 사이의 경계층이 뚜렷하게 형성되었다. 이러한 현상을 극복하기 위한 보완 실험을 통해 경계층 파쇄(破碎)를 위한 관 내 부속 구조물이 고안되었으며, 본 연구에서 제시된 구조물은 단거리 배송관로 내 준설토와 개질재의 혼합효율을 크게 향상시킬 수 있음을 확인할 수 있었다. This study utilised Computational Fluid Dynamics(CFD) for preliminary assessment of mixing efficiencies of 2-phase fluids in a pipe at which a slurry flow and an injected solidifier join, for the purposes of reducing trial-and-error-based instances of physical experiments and conducting the overall research in an economical way. Using OpenFOAM$^{(R)}$, we simulated behavior of 3-phase fluids under 18 different settings generated by changing diameters of a dredged soil transportation pipe, a quality improving material injection pipe and the confluence angle. While difference in mixing efficiencies amongst the instances was insignificant, discernible boundary layers amongst the materials were observed in all of the instances. In order to break the boundary layers, we designed a substructure inside a pipe and found out that it could remarkably improve mixing efficiencies particularly for short distance applications.

외상성 저안압황반병증 환자에서 유리체강내 공기주입술로 치료한 1예

박병준,신현진,김형찬,Byeong Jun Park,Hyun Jin Shin,Hyung Chan Kim 대한안과학회 2013 대한안과학회지 Vol.54 No.12

Purpose: To report a case of traumatic hypotony maculopathy treated by intravitreal air injection.<br /> Case summary: A 20-year-old female presented with decreased visual acuity in the left eye 2 days after trauma. Best corrected visual acuity (BCVA) was 0.5 and the intraocular pressure (IOP) was 5 mm Hg. Indirect ophthalmoscopy revealed chorioretinal folds in the macular area. Gonioscopy showed angle recession from 4 to 7 o’clock. Initially, pressure patching and conservative management were performed on the left eye 10 days after examination. However, deterioration of the chorioretinal fold was observed without any change in IOP. Finally, intravitreal air injection (0.5 cc) was performed 10 days after the start of conservative treatments. Following air injection, the normalization of IOP and gradual reduction of chorioretinal fold was observed. BCVA improved to 1.0 and IOP was maintained between 12 and 14 mm Hg for 24 months after the air injection.<br /> Conclusions: Intravitreal air injection may safely and effectively treat traumatic hypotony maculopathy.<br /> J Korean Ophthalmol Soc 2013;54(12):1935-1938

열전지용 황철석(FeS₂) 입자크기 변화에 따른 전기화학반응 메커니즘

박병준,Park, Byeong June 한국전기전자재료학회 2017 전기전자재료학회논문지 Vol.30 No.4

Pulverized $FeS_2$ (pyrite) gives different discharge test results with as-received $FeS_2$ electrodes. The as-received $FeS_2$ electrode shows three voltage plateaus during the discharge test. However, the ball-milled $FeS_2$ electrode shows two voltage plateaus. To interpret this result, the effect of $FeS_2$ particle size on electrochemical reactions is investigated by unit cell discharge tests, SEM and XRD. As a result, it is found that the transition reaction product ($Li_2+xFe+xS_2$) of $FeS_2$ explains the difference. The as-received $FeS_2$ reacts according to three reaction steps ($FeS_2{\rightarrow}Li_3Fe_2S_4{\rightarrow}Li_2+xFe_1+xS_2{\rightarrow}LiFe_2S_4$). However, ball-milled $FeS_2$ reacts without the $Li_2+xFe_1+xS_2$ stage. In this study, this result is explained by the difference in electrochemical reaction mechanism. The as-received $FeS_2$ has a larger radius than the ball-milled $FeS_2$. Therefore, the lithium ion has to diffuse into the $FeS_2$ unreacted core, and $Li_2+xFe_1+xS_2$, the transition reaction product of as-received $FeS_2$, is formed during this stage.

TRANSFER OF FOREIGN GENES INTO THE BRADYRHIZOBIUM JAPONICUM AND INOCULATION EFFECTS

박병준,김용웅,김광식,김길용,이용한 ( Byeong Jun Park,Yong Woong Kim,Kwang Sik Kim,Kil Yong Kim,Young Hwan Rhee ) 한국토양비료학회 1990 한국토양비료학회 학술발표회 Vol.1990 No.44

당뇨환자에서 당뇨망막병증과 베바시주맙 안내주입술이 맥락막 두께에 미치는 영향

박병준,정혜원,김형찬.Byeong Jun Park. MD. Hye Won Chung. MD. PhD. Hyung Chan Kim. MD. PhD 대한안과학회 2013 대한안과학회지 Vol.54 No.10

Purpose: To evaluate the effect of diabetic retinopathy on choroidal thickness and the changes of choroidal thickness after intravitreal bevacizumab injection (IVB) in diabetic patients. Methods: The present study included 105 patients (105 eyes). Patients were classified into 6 groups: control group (A); no change (B), mild (C), moderate (D), and severe (E) non proliferative diabetic retinopathy (NPDR); and proliferative diabetic retinopathy (PDR) (F), with 15 diabetic patients in each group. All patients underwent enhanced depth imaging spectraldomain optical coherence tomography (EDI OCT) to evaluate choroidal thickness. An additional 15 patients (15 eyes) with diabetic retinopathy treated with IVB were also included. These patients underwent EDI OCT before and 1 month after IVB. Results: Mean choroidal thickness was significantly thinner in the moderate and severe NPDR, and PDR groups compared with the control group. Moreover, when comparing sequential stages of diabetic retinopathy progression, the choroidal thickness in the moderate NPDR stage and PDR stage was found to be significantly thinner than in the mild and severe NPDR, respectively. Additionally, choroidal thickness was 187.3 μm before IVB and significantly decreased to 168.9 μm 1 month after IVB (p < 0.05). Conclusions: Choroidal thickness is related to the severity of diabetic retinopathy and is significantly decreased after IVB. J Korean Ophthalmol Soc 2013;54(10):1520-1525

35 kWh급 플라이휠용 초전도 베어링의 댐핑 특성평가

박병준,정세용,한상철,한상진,이대화,한영희,Park, B.J.,Jung, S.Y.,Han, S.C.,Han, S.J.,Lee, D.H.,Han, Y.H. 한국초전도학회 2012 Progress in superconductivity Vol.14 No.1

Superconductor flywheel energy storage system (SFESs) is an electro-mechanical battery with high energy storage density, long life, and good environmental affinity. SFESs have been developed for application to a regenerative power of train, the storage of distributed power sources such as solar and wind power, and a power quality improvement. As superconductor bearing is completely passive, it is not necessary to control a system elaborately but accurate analysis in mechanical properties of the HTS bearing is very important for application to SFESs. Stiffness and damping properties are the main index for evaluation the capacity of HTS bearings and make it possible to adjust rotordynamic properties while operating the rotor-bearing system. The superconductor bearing consists of a stator containing single grain YBCO bulks, a ring-type permanent magnet rotor with a strong magnetic field that can reach the bulk surface, and a bearing support for assembly to SFESs frame. In this study, we investigated the stiffness and damping properties of superconductor bearings in 35 kWh SFESs. Finally, we found that 35 kWh superconductor bearing has uniform stiffness properties depend on the various orientations of rotor vibration. We discovered total damping coefficient of superconductor bearing is affected by not only magnetic damping in superconductor bulk but also external damping in bearing support. From the results, it is confirmed that the conducted evaluation can considerably improve energy storage efficiency of the SFESs, and these results can be used for the optimal capacity of superconductor bearings of the SFESs.

에너지 저장장치용 슈퍼커패시터 이온 도핑 제어를 통한 에너지 밀도 향상 연구

박병준,유선미,양성은,한상철,노태무,이영희,한영희,Park, Byung-jun,Yoo, SeonMi,Yang, SeongEun,Han, SangChul,No, TaeMoo,Lee, Young Hee,Han, YoungHee 한국전력공사 2019 KEPCO Journal on electric power and energy Vol.5 No.3

최근 전력 계통에 사용되는 주파수 조정용(F/R) 에너지 저장장치에 대하여 높은 에너지 밀도와 장수명의 안정성에 대한 요구가 증대되고 있다. 이와 관련하여 슈퍼커패시터는 장수명과 급속 충방전 특성이 우수하므로 이러한 F/R 적용을 위한 에너지 저장장치로 적합하게 여겨지고 있다. 슈퍼커패시터는 단주기 F/R 영역의 보완 운전을 담당하고 전력계통에 설치된 ESS의 장주기 운영 수명을 연장함으로써 기존 용량을 담당하는 리튬 배터리의 설치 규모와 양을 획기적으로 줄일 수 있다. 하지만 낮은 에너지 밀도는 전력 계통과 같은 큰 시스템에서 적용에 한계가 있으며 여전히 배터리를 대체할 수 있는 높은 에너지 밀도 요구에 어려움을 겪고 있다. 그러나 최근에는 리튬이온 커패시터(Lithium ion capacitor; LIC) 구조가 3.8 V 이상의 전압 구간을 구현할 수 있기 때문에 전기이중층 커패시터(Electric double layer capacitor; EDLC) 구조보다 고에너지 밀도 구현을 위한 구조로 각광을 받고 있지만 여전히 상용화를 위해서는 여러가지 전기화학적 성능에 대한 구체적인 검증 및 개발이 필요한 실정이다. 본 연구에서는 LIC의 에너지 밀도와 관계되는 용량을 증대하기 위하여 새로운 전극사전-도핑 방법을 설계하였다. 양극 활물질은 0.1% 이하의 상대습도 분위기 드라이룸에서 기계적 강도와 음극 도핑을 안정되게 수행될 수 있도록 $100{\mu}m$의 두께로 제작되었다. 또한 접촉 저항을 최소화하기 위하여 제조된 전극은 상온에서 $65^{\circ}C$까지 열 압축공정을 실시하였다. 최종적으로 LIC 구조에 대한 다양한 사전-도핑법을 설계하고 그 메커니즘을 분석하여 용량과 전기화학적 안정성이 향상된 새로운 LIC 사전-도핑 방법을 제안하였다. Recently, demand for high energy density and long cycling stability of energy storage system has increased for application using with frequency regulation (F/R) in power grid. Supercapacitor have long lifetime and high charge and discharge rate, it is very adaptable to apply a frequency regulation in power grid. Supercapacitor can complement batteries to reduce the size and installation of batteries. Because their utilization in a system can potentially eliminate the need for short-term frequent replacement as required by batteries, hence, saving the resources invested in the upkeep of the whole system or extension of lifecycle of batteries in the long run of power grid. However, low energy density in supercapacitor is critical weakness to utilization for huge energy storage system of power grid. So, it is still far from being able to replace batteries and struggle in meeting the demand for a high energy density. But, today, LIC (Lithium Ion Capacitor) considered as an attractive structure to improve energy density much more than EDLC (Electric double layer capacitor) because LIC has high voltage range up to 3.8 V. But, many aspects of the electrochemical performance of LIC still need to be examined closely in order to apply for commercial use. In this study, in order to improve the capacitance of LIC related with energy density, we designed new method of pre-doping in anode electrode. The electrode in cathode were fabricated in dry room which has a relative humidity under 0.1% and constant electrode thickness over $100{\mu}m$ was manufactured for stable mechanical strength and anode doping. To minimize of contact resistance, fabricated electrode was conducted hot compression process from room temperature to $65^{\circ}C$. We designed various pre-doping method for LIC structure and analyzing the doping mechanism issues. Finally, we suggest new pre-doping method to improve the capacitance and electrochemical stability for LIC.

심장이식 수혜자의 사회적지지, 우울 및 건강상태

박병준,신나미,Park, Byung-Jun,Shin, Nah-Mee 한국중환자간호학회 2014 중환자간호학회지 Vol.7 No.1

Purpose: As the number of cases of heart transplantation (HT) and the survival rate have increased, concerns regarding post-HT life have grown. This study was conducted to explore the relationships of perceived social support to the depression and health status of HT recipients. Methods: This descriptive study targeted all recipients who had undergone HT at S University Hospital since 1994, and 32 recipients were recruited. Results: 90.6% of the recipients were men, and the average age at the time of surgery was $47.4{\pm}13.4$ years. The ejection fraction was increased from $18.47{\pm}5.63%$ to $63.25{\pm}7.57%$, and 31 cases of New York Heart Association (NYHA) class III and IV improved to class I or II after HT. The patients reported mild depression even with high perceived social support and improved health status after HT. Among those resource persons who offered support, they reported their spouse, doctors, and nurses as most meaningful to them. Conclusion: This study confirmed the positive effects of HT on the recipients' physical improvement. It also added the discovery that the importance of recipients' subjective perception of social support might be critical for their more successful recovery and adjustment to post-HT life. Focusing on a different approach to social support and types of social resources in the recovery phase is suggested for future studies on quality of life after HT.