Controlled post-sulfurization process for higher efficiency nontoxic solution-deposited CuIn_0.7Ga_0.3Se₂ absorber thin films with graded bandgaps

Jang, Jin Woo,Lee, Seung Min,Choi, Ik Jin,Cho, Yong Soo ELSEVIER SCIENCE 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.710 No.-

<P><B>Abstract</B></P> <P>A practical way of adjusting post-sulfurization process with variable durations is proposed to improve the cell-conversion efficiency of non-toxic solution driven CuIn<SUB>0.7</SUB>Ga<SUB>0.3</SUB>Se<SUB>2</SUB> absorber thin films. The degree of bandgap grading was controllable by changing the sulfurization time from 2 min to 30 min due to the dissimilar distribution of sulfur across the absorber layer. Deeper intensified distributions of Ga and S were responsible for enhancements in the open-circuit voltage and cell-conversion efficiency. A competitive efficiency of ∼8.81% for the 10 min-sulfurized CIGSSe cell was achieved with other promising parameters, i.e., short-circuit current density of 33.17 mA/cm<SUP>2</SUP>, open-circuit voltage of 0.496 V, and fill factor of 53.5%, resulting from the improved carrier collection and reduced recombination by the bandgap grading. This improved efficiency corresponds to a ∼15.6% enhancement compared to the unsulfurized sample.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Controlled post-sulfurization process enhances cell efficiency of CuIn<SUB>0.7</SUB>Ga<SUB>0.3</SUB>Se<SUB>2</SUB>. </LI> <LI> Sulfur penetrates easily toward the back contact with concentration gradient. </LI> <LI> A graded bandgap structure is responsible for the improved charge collection. </LI> <LI> The achieved cell efficiency of ∼8.81% corresponds to the ∼15.6% enhancement. </LI> <LI> Actual bandgap variations are projected on the basis of elemental distributions. </LI> </UL> </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>

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>

알코올이 Dynamic Posturography에 미치는 영향

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

연구보문 : 자연과학 ; 황산처리에 의한 불투수성 황근 종자의 발아촉진에 관한 연구

서상흠 ( Sang Heum Seo ),박민우 ( Min Woo Park ),장미하 ( Mi Ha Chang ),장일웅 ( Il Ung Jang ),심상인 ( Sang In Shim ),나영왕 ( Young Wang Na ),김수영 ( Soo Young Kim ),김석현 ( Seok Hyeon Kim ) 한국국제농업개발학회 2012 韓國國際農業開發學會誌 Vol.24 No.3

The reason of poor germination rate of hamabo mallow seed was speculated using TZ test to determine the viability of seed. Seeds showed high viability via TZ test were not germinated well. The quiescent seeds did not imbibed properly due to the hard seed coat and did not show further processes required for germination. Several well-known treatments for seed coat loosening and water uptake into seed were applied and compared for their efficiency. Stratification, hot water treatment, seed coat scarification, wet-cold treatment were revealed as less effective for improving germination although those treatments were common method for breaking dormant seed. Chemical scarification with sulfuric acid, however, effectively increased germinability and promptness index of hamabo mallow seeds. Optimal time for sulfuric acid treatment was 20 min. Seeds treated for 20 min showed improved germination percentage, germination speed, and promptness index of 80%, 13, and 1969 at 30 days after imbibition, respectively, in petri dish experiment. The values were greater than control seeds showed low values (12%, 1, and 183, respectively). The similar tendency was observed in the pot experiment that sulfuric acid treated seed were sown in artificially mixed soil (loamy soil:peatmoss:sand:compost = 5:2:2:1) and placed in greenhouse. Ultrastructure analysis of chemically scarified seed with sulfuric acid for 20 min by scanning electron microscopy did not show any noticeable changes in seed coat hardness and water uptake via hilum. But the only change after sulfuric acid treatment was removal of hilum cap that close the hilum and hider imbibition. Therefore, subsequent experiment was conducted to know the relationship between removal of hilum cap and facilitated imbibition by sulfuric acid treatment and whether the hilum cap removal directly influenced to the opening of micropyle. Water uptake velocity of seed treated for 20 min in concentrated sulfuric acid for was greater than control seed. This result implies that the crucial effect of sulfuric acid treatment is the removal of hilum cap that increase water uptake via micropyle in hamabo mallow.

분변토를 이용한 VOCs 흡착에 관한 기초연구

김재홍,손희정,김장호,김수생,서정민 동아대학교 환경문제연구소 1997 硏究報告 Vol.20 No.2

This study was carried out two point view that reuse of sludge and adsorption of benzene, toluene and o-xylene of VOCs in cast, carbonized cast and activated carbon. The cation exchange capacity of cast and carbonized cast were 59.2, 112 meq/l00g, respectively. The specific surface were 560, 800 ㎡/g, respectively. The average removal rates of benzene by 50g cast of 50% hydrous cast, anhydrous cast, carbonized cast, activated carbon were 15.0, 41.2, 88.2, 99.4% in 60min retention time. The average removal rates of toluene by 50g cast of 50% hydrous cast, anhydrous cast, carbonized cast, activated carbon were 12.5, 34.2, 88.2, 99.5% in 60min retention time. The average removal rates of o-xylene 50g cast of 50% hydrous cast, anhydrous cast, carbonized cast, activated carbon were 8.8, 28.5, 84.8, 98.1% in 60min retention time. The adsorption efficiency of test absorbent was in order of benzene > toluene > o-xylene.

Parapharyngeal Space에 발생한 Pleomorphic Adenoma의 치험례

장신남,백민주,김진수,변기정 大韓顎顔面成形再建外科學會 2003 Maxillofacial Plastic Reconstructive Surgery Vol.25 No.2

본 교실에서는 발생이 드문 부인두간극에 발생한 다형성 선종을 악하절개와 하악지 부위의 하악골 절단을 행한 이후에 둔적박리(blunt dissection)를 이용하여 종물과 주위의 구조물을 외과적으로 절제하였으며, 3년간의 추적 조사 결과 재발의 양상 없이 양호한 결과를 얻었기에 문헌고찰과 함께 보고하는 바이다. Pleomorphic adenoma is the most common of the benign salivary gland tumors. Pleomorphic adenoma accounts for 60% of all parotid gland tumors, 50% of submandibular gland tumors. and only 25% of sublingual gland neoplasms. Fifty percent of all oral minor gland tumors are pleomorphic adenomas of which 55% arise in the palate, 25% in the lip, 10% in the buccal mucosa, and 10% from all other oral and oropharyhgeal sites. The presence of tumors within the parapharyhgeal space is rare. Some investigators have reported pleomorphic adenomas originating in the deep lobe of the parotid gland advancing to involve this region, as well as primary pleomorphic adenomas of nonparotid origin. We present a case report of pleomorphic adenomas in the parapharyhgeal space with literature review. The tumor was completely removed under general anesthesia via submandibular incision with the division of mandible.

뇌하수체 종양 제거술 시행 후 뒤늦게 발생한 횡문근 융해증과 동반된 중추성 열

장제혁,최규남,김일환,노은지,김윤정,유충헌,고정해,박봉수,김태균,권민정,이순희,박정현 인제대학교 2008 仁濟醫學 Vol.29 No.-

Body temperature is controlled by thermoregulatory center of the hypothalamus. We report a case of 24 years old man with central fever. He was subjected to a partial excision of pituitary tumor compressing optic chiasm four years ago. He has received hormonal therapy for panhypothyroidism after removal of pituitary tumor. And He received gamma knife operation for partially contrast-enhancing masses in suprasellar and both hypothalamic areas that is probably postoperatively remnant or recurrent tumor of pituitary adenoma. One year after gamma knife operation, he presented with a febrile syndrome of unknown origin including rhabdomyolysis. All usual investigations proved negative. We diagnosed him as central fever with rhabdomyolysis. He received medical ICU care with cooling bed, ice pack. And his symptom improved. Postoperative hyperthermia may result following resection of the pituitary tumor. When central fever is suspected taking note of past history, a quick recognition of course of fever can help reduce the using of unnecessary antibiotics and hospital stay.

건축음향의 국제규격화 체계

장길수,송민정 동신대학교 환경연구소 1998 환경연구 Vol.3 No.1

ISO(국제표준화기구)는 120여개국이 참여하는 세계적인 기구이다. 각종 기술위원회에서는 산하조직에 597개의 분과위원회(SC : Sub-Committee)와 작업반(WG : Working Group)을 두고 국제규격의 제정, 수정 및 개정 둥의 업무를 수행하며, 그 결과로서 ISO규격이 작성된다. 본 조사연구는 IS0/TC43/SC2(건축음향)의 주요 활동사항을 정리해 보았다. ISO(the International Organization for Standardization) is a worldwide federation of national standards bodies, from some 120 countries. The technical work of ISO is highly decentralized, carried out in a hierarchy of some 2,700 technical committees(TC), sub-committees(SC) and working groups(WG). The results of the ISO work are published as International Standards. In this paper, main fields of work at the ISO/TC43/SC2 are described.

구조 비선형성을 고려한 상태공간 천음속 날개꼴의 공력탄성해석

장민성,이종수 연세대학교 산업기술연구소 1999 논문집 Vol.31 No.2

An aeroelastic stability analysis is numerically simulated for two-degree-of-freedom transonic airfoils with some structural nonlinearities in torsional stiffness. A state-space method is used to model the characteristic values of the unsteady transonic flow. Structural nonlinearities considered in the present study are free-play, bilinear spring and friction. The stability of the aeroelastic system is determined by converging values of the angle of attack and bending displacement in time domain. The flutter behavior and vibratory amplitudes are examined for a number of flight conditions and airfoil geometry configurations.