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>

Caffeine 과 Glucose 투여가 지구성 운동중 대사 및 호흡기능에 미치는 효과

박해근,전종귀,홍성표,민창기 忠南大學校體育科學硏究所 1986 體育科學硏究誌 Vol.4 No.1

Twelve male students (major in physical education; non-coffee drinkers; 6 endurance athletes; 6 non-athletes) were studied to determine the effects of caffeine, and Glucose feedings on submaximal endurance performance. Each subject performed three submaximal cycling trials at an absolute intensity of 900kpm. The trials were randomized to negate any possible order or training effects. For the caffeine trial, 2.5 mg/kg body weight of caffeine in 250ml of artificially sweetened barley tea was ingested twice one hour and 30.min prior to the ride. In the glucose trial, 0.5g/kg. body weight of glucose in 250m1 of barley tea was ingested twice one hour and 30 min prior to the ride. During the control trial, 250ml of artificially sweetened barley tea was ingested twice one hour and 30 min prior to the ride. obtained data from the three trials were analyzed with one way ANOVA for repeated measures design. Significant differences between means were located using a multivariate comparison. The level of significance was established at p<0. 05. The results were summerized as follows : Ingestion of glucose elevated blood glucose and insulin levels at rest , but no significant differences in blood glucose concentration were found between the three trials . Glucose ingestion resulted in rapid hypoglycemia and inhibition of FFA mobilization during exercise. Caffeine ingestion increased significantly in VE, Vo2 and plasma osmolarity during the exercise. But caffeine ingestion failed to elevate plasma FFA concentration, HR and blood pressure significantly. Glucose or caffeine ingestion did not change in blood lactate, Hb , plasma Na+ concentration, Hit and RQ during exercise. In the above results, It was suggested that ingestion of caffeine prior to the exercise fail to increase in lipid metabolism during exorcise and may have some detrimental effects on endurance performance besides psychological ergogenic effect of caffeine, and that glucose ingestion prior to the exercise elevate blood glucose and insulin level at rest but may have detrimental effect of endurance performance because of rapid hypoglycemia caused by hyperinsulinemia.

[논문]문화, 로컬리티, 주체형성 : 21세기 인문학의 방향모색

홍성민 부산대학교 한국민족문화연구소 2011 로컬리티 인문학 Vol.0 No.6

부산의 지역연구는 그동안 법적이고 제도적인 수준에서 이루어져 왔다고 볼 수 있다. 또 지역의 문화를 연구하는 경우에도 향토성에 초점을 두었다는 점에서 그것은 민속학의 수준을 넘어서지 못했던 것이다. 그런데 현대 자본주의의 문화적 영향력을 무시한 채 부산의 지역성을 연구하는 것은 여러 가지 문제가 있다. 따라서 전자의 연구방식을 지역연구(the local)라고 한다면, 후자의 문제의식을 지역성(thelocality) 연구라고 이름 붙여 볼 수 있을 것이다. 부산의 로컬리티 연구는 결국 이 두가지 접근방식이 종합적으로 이루어질 때 바람직한 결과를 얻을 수 있을 것이다. 한편 그동안 로컬리티 연구가 전자에 치중되었다고 필자는 판단한다. 따라서 본 논문에서는 후자의 접근방식을 강조하면서 소비생활과 정치적 의식의 상관관계를 추적해 보았다. The regional studies for Busan have been executed in order to find legal and institutional characteristics. And the cultural studies for the Busan have been so focused on the regionalities that they could not overcome the approach of ethnography. But I believe that cultural dominance of modern capitalism should not be forgotten in doing research of the regional studies. The regional studies could be called as method of the local, while cultural dominance studies could be named as method of the locality. The best way for the Busan could be achieved only after the two method should be synthesized. In my opinion studies for Busan have been done by the method of the local. In this article I would like to emphasize the method of the locality, showing the correlation between consumption and political value.

CDMA 시각 동기용 GPS 시스템의 고주파부 설계 및 제작

홍성일,김영민,변건식 東亞大學校 附設 情報通信硏究所 1996 情報通信硏究所論文誌 Vol.4 No.1

When GPS(Global Positioning System) is used as synchronous signal in CDMA digital cellular base station system and high speed digital synchronous communication network, antenna cable lengh is increased, comparing with other GPS application such as positioning or car navigation. In this paper, it is proposed that a type of new GPS antenna system including RF stage for reduction of cable loss in case of long cable. The antenna system with TMPA(Truncated-corners Microstrip Patch Antenna) is designed and fabricated because GPS signal has RHCP(Right-Hand Circular Polarization), consequently antenna size can be made small size. NAN(Low Noise Amplifier) is designed by using HEMT(High Electron Mobility Transistor) which has lower noise figure and better AGC characteristics at low voltage than GaAs FET, and we equipped mixer, in GPS antenna unit, which converts from 1575.42MHz to 75.42MHz. As result of comparing between typical system and proposed system when cable length is 60m, 63dB, 55dB and 25dB gain are obtained for RG-316/U, RG-58C/U and RG-213/U, and better characteristics are achieved than typical system as far as cable length is longer.

표본화 및 유지회로 성능향상에 관한 연구

홍국태,이성대,정강민 成均館大學校 科學技術硏究所 1995 論文集 Vol.46 No.1

In this paper, a high speed, high accuracy sample and hold circuit that minimizes the hold step error by using a new circuit architecture is proposed. This new sample-and-hold scheme takes advantages of the speed of the open loop sample-and-hold circuit in the SAMPLE time and the cancellation of charge injection in the HOLD time. It operates above 50MHz with 0.3mV hold step error.

악관절 강직의 치험 36예 보고

홍성철,오재욱,김수신,백세민,B.CELLIKOZ 大韓成形外科學會 1990 Archives of Plastic Surgery Vol.17 No.6

Ankylosis of the mandible is a serious and most disabling condition. Impairment of speech, difficulty with mastication, poor oral hygience, facial asymmetiry, and mandibular micrognathia invariably result in much physical and psychologic disability, particularly in young children with complete inability to open the mouth. We performed a one stage reconstruction of temporomandibular joint at the same time as performing multiple additional oateotomies to correct the facial asymmetiry. Temporomandibular joint was reconstructed with costchondral graft or interpositional arthroplasty with silastic implant. Breakdown of 36 cases is as follows. 1. Most prevelent incidence is at age of 21-30 revealed no sex predilection. 2. Trauma was the most common cause, found in 8 patients. 3. Average preoperative mouth opening was 21mm and postroperative mouth opening was 39.8mm 27 patients with interincisor lengh greater than 30mm resumed a satisfactory life style with no discomfort. 4. Anethesia was done by fiberoptic nasotracheal intubation in 31 patients. 5. Postroperative complication included infection in 3 patients which was treated with local and systemic antibiotic therapy. 1 patient developed transient lower lip hypoesthesia.1 patient complained remained facial asymmetiry, which was corrected by fat injection. 6. In 20 patients simultaneous total correction of temporomandibular joint ankylosis and facial asymmetry were done.

이슬람經濟學 : Definitions and Approaches 그 定義와 接近方法

洪性敏 韓國外國語大學校 中東問題硏究所 1987 硏究論叢 Vol.1987 No.6

高周波 通信用 FIR Digital 필터의 設計

洪國泰,李成大,鄭康敏 成均館大學校 科學技術硏究所 1994 論文集 Vol.45 No.2

In this paper, a programmable high-sample-rate FIR digital filter was designed for a highbandwidth communication system. A fully parallel bit-level pipelined transpose-form carrysave architecture using CSD coefficients was adopted for high-speed operation. In this system, multiplication can be translated to simple shift-addition processes. For programmability of filter coefficients, two decoders and a few registers are added, and the shifting processes of input data are controlled according to the data registered. Therefore, the speed performance of the designed filter is comparable to the case of a non- programmable filter.

日本語 作文 指導法과 그 諸問題에 關한 硏究 : 韓國에 있어서의 日本語 敎育이라는 觀點에서

閔聖泓 韓國外國語大學校附設 外國語敎育硏究所 1986 외국어교육연구 Vol.- No.3