Ether-free polymeric anion exchange materials with extremely low vanadium ion permeability and outstanding cell performance for vanadium redox flow battery (VRFB) application

Cha, Min Suc,Jo, Sang Woo,Han, Seung Hui,Hong, Soo Hyun,So, Soonyong,Kim, Tae-Ho,Oh, Seong-Geun,Hong, Young Taik,Lee, Jang Yong Elsevier 2019 Journal of Power Sources Vol.413 No.-

<P><B>Abstract</B></P> <P>Ether-free poly(<I>p</I>-phenylene)-based anion exchange membrane materials with outstanding vanadium ion blocking properties are reported. The synthesized ionomers with a rigid backbone structure show small dimensional variations despite the high ion exchange capacities. Among the synthesized membranes, the QPPP-2 membrane with ion exchange capacity of 2.1 meq·g<SUP>−1</SUP> exhibits high anion (OH<SUP>−</SUP>, SO<SUB>4</SUB> <SUP>2−</SUP>, and Cl<SUP>−</SUP>) conductivity. The QPPP-2 membrane shows an extremely low diffusion coefficient (2.12 × 10<SUP>−9</SUP> cm<SUP>2</SUP> min<SUP>−1</SUP>) for VO<SUP>2+</SUP>, which is much lower than that of Nafion 115 (2.88 × 10<SUP>−6</SUP> cm<SUP>2</SUP> min<SUP>−1</SUP>), indicating the vanadium ion blocking property of QPPP-2. Moreover, the chemical and operational stabilities of the membranes are investigated <I>via</I> ex situ soaking tests in 0.1 M VO<SUB>2</SUB> <SUP>+</SUP> solution and in situ operation tests for 100 cycles, respectively. The vanadium redox flow battery single cell assembled with the QPPP-2 membrane exhibits a coulombic efficiency of 99%, voltage efficiency of 87%, and energy efficiency of 86% during 100 cycles at 80 mA cm<SUP>−2</SUP>. The excellent chemical, morphological, and electrochemical properties of the QPPP-2 membrane make it suitable for use in vanadium redox flow battery.</P> <P><B>Highlights</B></P> <P> <UL> <LI> AEMs are fabricated by a Ni(0)-catalyzed cross-coupling reaction. </LI> <LI> The synthesized ionomers indicated excellent dimensional and chemical stability. </LI> <LI> Ether-free polymeric AEMs showed extremely low vanadium ion cross over. </LI> <LI> The performance of developed AEM showed high EE (87%) with high capacity retention. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Crosslinked anion exchange membranes with primary diamine-based crosslinkers for vanadium redox flow battery application

Cha, Min Suc,Jeong, Hwan Yeop,Shin, Hee Young,Hong, Soo Hyun,Kim, Tae-Ho,Oh, Seong-Geun,Lee, Jang Yong,Hong, Young Taik Elsevier 2017 Journal of Power Sources Vol.363 No.-

<P><B>Abstract</B></P> <P>A series of polysulfone-based crosslinked anion exchange membranes (AEMs) with primary diamine-based crosslinkers has been prepared via simple a crosslinking process as low-cost and durable membranes for vanadium redox flow batteries (VRFBs). Chloromethylated polysulfone is used as a precursor polymer for crosslinked AEMs (CAPSU-x) with different degrees of crosslinking. Among the developed AEMs, CAPSU-2.5 shows outstanding dimensional stability and anion (Cl<SUP>−</SUP>, SO<SUB>4</SUB> <SUP>2−</SUP>, and OH<SUP>−</SUP>) conductivity. Moreover, CAPSU-2.5 exhibits much lower vanadium ion permeability (2.72 × 10<SUP>−8</SUP> cm<SUP>2</SUP> min<SUP>−1</SUP>) than Nafion 115 (2.88 × 10<SUP>−6</SUP> cm<SUP>2</SUP> min<SUP>−1</SUP>), which results in an excellent coulombic efficiency of 100%. The chemical and operational stabilities of the membranes have been investigated via ex situ soaking tests in 0.1 M VO<SUB>2</SUB> <SUP>+</SUP> solution and in situ operation tests for 100 cycles, respectively. The excellent chemical, physical, and electrochemical properties of the CAPSU-2.5 membrane make it suitable for use in VRFBs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The crosslinking between polymer chains are constructed by 4,4′-diaminobenzophenone. </LI> <LI> The crosslinked AEMs were fabricated by commercial polysulfone (PSU; Udel<SUP>®</SUP> P-3500). </LI> <LI> The crosslinked AEM based on PSU indicated good chemical and dimensional stability. </LI> <LI> The performance of crosslinked AEM showed high EE (86%) with high capacity retention. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

알코올이 Dynamic Posturography에 미치는 영향

이진춘,고의경,장민호,이병주,백무진,노환중,왕수건,전경명 대한이비인후과학회 1999 대한이비인후과학회지 두경부외과학 Vol.42 No.2

손가락 끝 점을 이용한 손 형상 인식

김종민,이웅기,장근실,양환석,허진경,박승규 朝鮮大學校 統計硏究所 2007 統計硏究所論文誌 Vol.9 No.1

최근 사용자 친화형 유저 인터페이스 구현을 위해 인간의 손 형상을 실시간으로 인식하는 연구의 중요성이 부각되고 있다. 그러나 인간의 손은 자유도가 크기 때문에 손 형상을 정확히 인식하기란 매우 어렵고 또한 피부색과 유사한 색을 가지는 복잡한 배경에서는 더욱 곤란하다. 본 논문에서는 별도의 센서를 부착하지 않고 카메라를 사용하여 피부색 정보에 의한 손 형상을 분할한 후 손가락 끝 점을 찾는다. 찾은 손가락 끝 점을 이용하여 방향을 탐지하는 알고리즘에 대해 기술한다. 이 방법은 템플리트 매칭을 이용하여 손가락 끝 점을 탐색한 후 찾은 손가락 끝 점과 손목의 중심을 이용하여 전, 후, 좌, 우 방향을 탐지한다. 제안하는 방법을 이용하여 3D 가상현실 공간에서의 네비게이션(Navigation)에 응용하였으며, 실험결과 전진, 후진 및 좌측, 우측의 방향전환도 매우 좋은 결과를 보였다. 또한 본 논문에서 제안하는 방법은 마우스, 키보드, 조이스틱 등의 조작 없이 전, 후, 좌, 우 방향전환을 사용자가 직관적으로 지시함으로써 보다 자연스러운 인간과 컴퓨터의 상호작용을 제공할 수 있을 것이다.

자바를 이용한 마이크로 프로세서 시뮬레이터 개발에 관한 연구

김영민,허원,기장근 公州大學校工科大學生産技術硏究所 1998 論文集 Vol.6 No.-

Educational software tends to be momotonous without the interaction between instructors and students. and unidirectional teaching system can't overcome these barriers because the learning process is momotonous without the bidirectional communication. The advanced network system can solve these problems. In this study, a bidirectional microprocessor simulator is developed and a new teaching model is proposed using the simulator. It was named JMPS(JAVA Microprocessor Simulator), which is a software to teach the microprocessor principles and applications. It has two advantages. First, it can teach the principles and applications of microprocessor effectively. Second, it runs on Internet and provides easy communication between a teacher and students.

다양한 적송잎 추출물의 항생제 내성 황색포도상구균에 대한 항균활성 검증

Nam-Young Kim(김남영),Min-Kyung Jang(장민경),Myung Je Jeon(전명제),Dong-Geun Lee(이동근),HyeJi Jang(장혜지),Seung Woo Lee(이승우),Mihyang Kim(김미향),Sung Gu Kim(김성구),Sang-Hyeon Lee(이상현) 한국생명과학회 2010 생명과학회지 Vol.20 No.4

병원 내 감염의 주된 원인균으로 알려진 황색포도상구균(5. aureus)과 항생제 내성 황색포도상구균(PRSA, MRSA)에 대해 항균활성이 우수한 천연 항균성 물질을 검색하기 위해 적송잎을 대상으로 열수-헥산(HWH), 열수-에탄올(HWE), 헥산, 에탄올 및 열수 등으로 획득된 추출물들로 항균활성을 조사하였다. 헥산, 에탄올, 열수-헥산, 열수-에탄올 추출물들은 그람양성 대표세균인 고초균(B. subfilis), 황색포도상구균 표준균주, 항생제 내성균주인 PRSA 및 MRSA에 대해서 항균활성을 나타내었으며, 특히 MRSA (ATCC 33591) 균주에 대해 다른 균주들 보다 높은 항균활성을 나타냈다. 열수 추출물은 황색포도상구균 표준균주 및 MRSA에서만 항균활성을 나타냈지만, 항균활성은 가장 높아 50 ㎎/㎖의 농도에서 33 ㎜의 생육저해환을 나타냈다. 각 균주들에 대한 생장의 최소저해 농도(MIC)는 HWH 및 HWE 추출물이 모두 0.05 ㎎/㎖의 농도로 가장 낮았고, 열수추출물이 0.5 ㎎/㎖의 농도였으며, 에탄올 추출물은 5 ㎎/㎖의 가장 높은 농도를 나타냈다. 모든 추출물들은 121℃에서 20분간의 열처리 후에도 항균활성이 유지되었으므로 열에 대해 안정한 물질임을 알 수 있었다. 본 연구결과로 식품산업에서 솔잎 추출물을 천연 항균제로 사용할 수 있을 것으로 기대할 수 있다. investigated antimicrobial activities of various pine (Pinus densiflora) needle extracts against antibiotic resistant strains of Staphylococcus aureus. Hot water extract showed the highest antimicrobial activity against normal and methicillin resistant Staphylococcus aureus (MRSA), however, it exhibited no antimicrobial activity against penicillin resistant S. aureus (PRSA). Hot water-hexane (HWH), hot water-ethanol (HWE), hexane, and ethanol extracts showed antimicrobial activity against S. aureus, PRSA and MRSA. Minimum inhibitory concentrations (MIC) of HWH, HWE, hexane, and ethanol extracts were 0.05, 0.05, 0.5 and 5 ㎎/㎖ respectively, and HWH and HWE extracts showed the strongest antimicrobial activity among these extracts. Antimicrobial activities of pine needle extracts were stable after heating at 121℃ for 20 min. These results suggested that pine needle extracts can be used as an effective natural antimicrobial agent for food and medical industries.

Layer-controlled thinning of black phosphorus by an Ar ion beam

Park, Jin Woo,Jang, Sung Kyu,Kang, Dong Ho,Kim, Doo San,Jeon, Min Hwan,Lee, Won Oh,Kim, Ki Seok,Lee, Sung Joo,Park, Jin-Hong,Kim, Kyong Nam,Yeom, Geun Young Royal Society of Chemistry 2017 Journal of Materials Chemistry C Vol.5 No.41

<▼1><P>BP thinning was carried out using a monoenergetic Ar<SUP>+</SUP> ion beam and the BP could be thinned without damaging the surface.</P></▼1><▼2><P>Black phosphorus (BP) is one of the most interesting two-dimensional (2D) layered materials due to its unique properties, including a band gap energy change from 0.3 eV (bulk) to 2.0 eV (monolayer) depending on the number of BP layers, for application in nanoelectronic devices. In general, 2D layered materials including BP have limitations in terms of synthesis due to the process factors such as time, temperature, <I>etc.</I>, and thus, a thinning technique from the bulk material to a 2D material needs to be used while controlling the removed layer thickness. In this study, layer-controlled thinning of BP was performed by using a controlled Ar<SUP>+</SUP> ion beam method and the BP thinning characteristics were investigated. By using the near monoenergetic ion energy in the range of 45–48 eV, BP could be thinned with the thinning rate of ∼0.55 nm min<SUP>−1</SUP> down to bilayer BP without increasing the surface roughness and without changing the chemical binding states. The BP oxide on the pristine BP could also be successfully removed using the same Ar<SUP>+</SUP> ion beam. 2D BP field-effect transistors (FETs) fabricated with the thinned bilayer–10-layer BPs exhibited electrical characteristics similar to those of pristine BP FETs suggesting no electrical damage on the BP layers thinned by the controlled monoenergetic Ar<SUP>+</SUP> ion beam.</P></▼2>

온라인 화상 인증을 위한 분산 객체 활성화 시스템

허진경,양환석,박승규,장근실,김종민 朝鮮大學校 統計硏究所 2007 統計硏究所論文誌 Vol.9 No.1

클라이언트로부터 전송되는 인증 데이터를 실시간으로 서버에서 분석하여 처리하는 시스템의 경우에는 입력되는 데이터의 양에 비례하여 서버의 부담은 증가하게 된다. 이때 서버에서는 데이터의 병목현상이 발생하게 되고, 이는 바로 전체적인 시스템의 성능을 저하시키는 결과를 초래하게 된다. 본 논문에서는 데이터 처리의 병목현상을 해결하여 시스템의 성능을 높일 뿐만 아니라, 인터넷상의 유휴 서버들을 활용할 수 있게 하기 위한 방안으로 분산처리 기술을 이용한 전처리 작업 시스템과 그 성능을 향상시키기 위한 분산 객체 활성화 시스템을 제안한다.

고압멸균 처리시간에 따른 닭 체내 조류인플루엔자와 뉴캐슬병 바이러스의 멸균효과

이진주 ( Jin Ju Lee ),김동혁 ( Dong Hyeok Kim ),임정주 ( Jeong Ju Lim ),김대근 ( Dae Geun Kim ),민원기 ( Won Gi Min ),이후장 ( Hu Jang Lee ),장홍희 ( Hong Hee Chang ),김석 ( Suk Kim ) 한국예방수의학회(구 한국수의공중보건학회) 2011 예방수의학회지 Vol.35 No.4

Avian influenza (AI) and Newcastle disease (ND) distress a variety of avian species, especially domestic poultry. Severe syndromes are caused by highly virulent specific virus strains termed highly pathogenic AI and velogenic ND viruses, which are potential agrobioterrorism agents. This outbreak emphasizes the need for continuing cooperation between public health and veterinary medical communities in controlling AI and ND when it has a zoonotic potential. Up to date, the stamping out and burying system were applied for controlling methods against these highly infectious diseases in the ordinary way, however these methods had many environmental problems, including leachat and effluvium. Thus, we assessed that sterilization effect of AI and ND virus dependent on several treatment conditions, such as autoclaving time and cutting types of chicken. As a result, we found that the cutting type of chicken meat revealed a reduced HA titer (20) against both of AI and ND virus after 10 min of autoclaving, while whole chicken showed same titer after 30 and 60 min. Therefore, we propose that the conditions of treatment on infected chicken should be developed for convenient, affordable, and effective prevention methods against for AI and ND.

Metaverse in the human mind

Min, Jang Geun 한국콘텐츠학회 2022 ICCC International Digital Design Invitation Exhib Vol.2022 No.07