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.

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

생물변환 천연식용색소 생산공정기술 개발 : Ⅰ. 홍화 황색소의 안정성에 미치는 pH 및 온도의 영향 Ⅰ. Effect of pH and Temperature on the Stability of the Yellow Pigment from Carthamus tinctorious L.

홍성현,박성길,이종민,한태룡,백영숙,정인식 경희대학교 생명자원과학연구원 1999 硏究論文集 Vol.20 No.-

홍화로부터 열에 의한 안정성을 검토하였다. 황색소의 분해반응은 산성, 중성, 염기성 조건에서 UV/Vis spectral measurement에 의해 조사되었다. 시간변화에 다른 흡광도를 측정해 본 결과 온도가 상승함에 따라 황색소의 분해되는 정도가 점차적으로 증가하는 것을 확인 할 수 있었다. 40℃에서 황색소의 분해 반감기는 pH3.0, pH7.0, 그리고 pH12.0에서 각각 112.1, 39.3 과 25.3 시간이었다. 이것은 황색소가 pH3.0에서 비교적 더 안정함을 말한다. pH3.0, 7.0 그리고 12.0에서 황색소의 activation energy는 각각 519, 15.0 그리고 12.3 kJ/mol이었다 We investigated thermal stability of yellow pigment from Carthamus tinctorious L. Decomposition reactions of yellow pigment were monitored at acidic, neutral and alkaline conditions by UV/Vis spectral measurement. Decomposition of yellow pigment increased as temperature increased Decomposition half lives of yellow pigment at 40℃ were 112.1 39.3, and 25.3 hrs at pH 3.0 , pH 7.0, and pH 12.0, respectively, indicating that yellow pigment is more stable at pH 3.0. The activation energies of yellow pigment at pH 3.0, pH 7.0, and pH 12.0 were 51.9, 15.0, and 12. 3 kJ/mol, respectively.

中·長距離달리기의 科學 : 生理學的 先行硏究와 現場適用

민창기,홍성표,김동건,전종귀 忠南大學校體育科學硏究所 1985 體育科學硏究誌 Vol.3 No.1

There are many difficulties in bridging the gap between scientific abservation and the assimilation into sports performance. The purpose of this review is to provide a digest of the technical aspects of research that form the scientific basis for the concepts that affect the sports of middle and long distance running. The authors reviewed the previous researchs about the following contents: the anatomical, physiological characteristics of the middle, long distance runner; the physiological responses during middle, long distance running; training for the systems of aerobic metabolism; the beforehand researches and their applications.

감조하천의 유로단면변화에 따른 유황해석

민병형,민일규,이승휘,박한기,박홍준 東亞大學校 建設技術硏究所 1997 硏究論文集 Vol.21 No.2

The subject of this study apply to KyungSangNamDo Sachun-Si Sachun-bay sea area for builds up a industrial complex, and inquire into the phenomenon in compared after with before reclamation. I investigated, how to remove these harmful influence and make a estimate that a water-level, flow direction and river-bed evolution by inflow of river, wave' s attack. So we have come to the conclusion as follow. 1. Water Level : After reclamation, the water-level is ascended, but the water-level is stable after dredging and changing water-course. 2. Velocity of Flow : After reclamation, back water broke out, the velocity of flow was faster after dredging and changing water-course, but the velocity of flow came to be stable in the downstream. 3. River-bed Evolution : After reclamation, the severe erosion occurred in the front of revetment, but after dredging and changing the water-course as the new stable water-course constituted, river bed evolution decreased and the flood wave flow smoothly. 4. After reclamation, the water-level remarkably increased, but the velocity of flow was nearly the same.

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.