Energy storage capabilities of nitrogen-enriched pyropolymer nanoparticles fabricated through rapid pyrolysis

Yun, Young Soo,Kim, Yu Hyun,Song, Min Yeong,Kim, Na Rae,Ku, Kyojin,An, Ji Su,Kang, Kisuk,Choi, Hyoung Jin,Jin, Hyoung-Joon Elsevier 2016 Journal of Power Sources Vol.331 No.-

<P><B>Abstract</B></P> <P>Nanostructured pyropolymers contain significant amounts of redox-active heteroatoms, have high specific surface areas, and a defective carbon microstructure, indicating good potential for pseudocapacitive charge storage. In this study, nitrogen-enriched pyropolymer nanoparticles (N-PNs-50) are fabricated from polyaniline nanotubes through rapid pyrolysis at 50 °C min<SUP>−1</SUP>. N-PNs-50 exhibit a nitrogen content of 9.8 wt%, a high specific surface area of 875.8 m<SUP>2</SUP> g<SUP>−1</SUP>, and an amorphous carbon structure with an I<SUB> <I>D</I> </SUB>/I<SUB> <I>G</I> </SUB> intensity ratio of 0.95. These unique characteristics lead to good electrochemical performances, in which reversible capacities of 660 and 255 mAh g<SUP>−1</SUP> are achieved for Li-ion and Na-ion storage, respectively, with favorable voltage characteristics (<1.5 V for Li-ions and <1.2 V for Na-ions). This study provides a more feasible production method for nitrogen-doped pyropolymers and their practicable electrochemical performances for use as an anode in energy storage devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nanostructured pyropolymers (N-PNs-50) were fabricated by rapid pyrolysis. </LI> <LI> N-PNs-50 exhibited a nitrogen content of 9.8 wt% and amorphous carbon structure. </LI> <LI> N-PNs-50 exhibited a high specific surface area of 875.8 m<SUP>2</SUP> g<SUP>−1</SUP>. </LI> <LI> 660 and 255 mAh g<SUP>−1</SUP> were achieved for Li-ion and Na-ion storage, respectively. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Nitrogen-enriched pyropolymer nanoparticles (N-PNs-50) were fabricated from polyaniline nanotubes through rapid pyrolysis at 50 °C min<SUP>−1</SUP>, showing superior electrochemical performances.</P> <P>[DISPLAY OMISSION]</P>

액상 TiO₂를 이용한 Rhodamine B 광촉매 분해

나영수,김도한,이송우,송승구 부산대학교 환경문제연구소 1998 環境硏究報 Vol.16 No.-

Rhodamine B 광분해 반응성을 연구하기 위하여 UV, TiO_2 그리고 TiO_2와 UV를 동시에 사용하여 염료 분해 실험을 행하였다. 그리고 pH, 초기 Rhodamine B 농도와 TiO_2 투여 농도에 대한 염료 분해에 관하여 실험하였다. 이때 TiO_2와 UV를 동시에 사용한 경우가 가장 높은 분해속도를 나타내었으며, TiO_2 투여량 증가와 pH가 높을 수록 분해효율이 증가하였으며, 초기 염료 농도가 높을 수록 감소하였다. 그리고 분해 속도는 pseudo-1st order로 나타났다. The photocatalytic activation of Rhodamine B in aqueous titanium dioxide suspensions has been studied and compared with different methods: UV Light, TiO_2, and TiO_2 with UV illumination. The influence of pH, initial Rhodamine B concentration and TiO_2 concentration on reaction rate has been investigated in detail. The photocatalytic degradation with TiO_2 and UV illumination showed higher activity than only UV or TiO_2. Reaction rate Increased with TiO_2 concentration and pH but decreased with initial Rhodamine B concentration. The decomposition showed pseudo-1st order reaction.

관계데이터베이스에서의 다치종속성의 결정문제에 관한 연구

宋榮宰,羅仁燁 慶熙大學校 1987 論文集 Vol.16 No.-

Database theory has recently been developing rapidly as a field of wide range closely related to a variety of fields. Especially, of the dependency theories of relational database, a recent trend considered important has been studied. Relational database has been represented by Functional Dependency (FD), Multi-valued Dependency (MVD), Join Dependency (JD), etc.; these, however, have problems of semantic constraint because they deal mainly with the relations of the entity of attribute. In this thesis, I have studied a new concept of constraint: Constraint MVD which makes it possible to deal with semantic constraint with which MVD, FD, and JD in relational database were unable to deal in models. Thus, a partial constraint of database maintaining the whole constraint, the expression of the dependency of data can be put to efficient use and updating operation of database can be reduced. The introduction of MVD has elucidated problems involved therem in. and I have presented a method of expression by which data in a schema can satisfty the dependency included the dependency set. The gradually wide-spreading use of computes in our daily life will make database match man's memory: and it is expected that the dependency for the use of computers to increase will read to a continued study of database with will go beyond the functioning fo man's memory and will eventually give rise to a theoretical system to formulate paralled and distributed processing and other data models.

색상 측정 기기를 이용한 복합레진 적층 수복과 단일 수복의 색상 비교 분석

송영상,김자현,이빈나,장지현,장훈상,황윤찬,오원만,황인남 大韓齒科保存學會 2012 Restorative Dentistry & Endodontics Vol.37 No.2

Objectives: This study analyzed the difference in color caused by different thickness in enamel layer of composite resins when applied with single and layering placement technique, and evaluated if the results agreed with the shade guide from the manufacturers to verify reliability of the color matching process of the manufacturers. Materials and Methods: For single composite resin samples, 6 mm diameter and 4 mm thickness cylindrical samples were fabricated using Ceram-X mono (DENTSPLY DeTrey) and CIE L*a*b* values were measured with spectrophotometer. Same process was done for layering compositie resin samples, making 3 dentinal shade samples, 4 mm thickness, for each shade using Ceram-X duo (DENTSPLY DeTrey) and enamel shade resins were layered in 2 mm thickness and CIE L*a*b* values were measured. These samples were ground to 0.2 mm thickness each time, and CIE L*a*b* values were measured to 1 mm thickness of enamel shade resin. Results: Color difference (△E*) between single and layering composite resin was 1.37 minimum and 10.53 maximum when layering thicknesses were between 1 mm and 2 mm and 6 out of 10 same shade groups suggested by manufacturer showed remarkable color difference at anythickness (△E* > 3.3). Conclusion: When using Ceram-X mono and duo for composite resin restoration, following the manufacturer's instructions for chossing the shade is not appropriate, and more accurate information for Ceram-X duo is needed on the variation and expression of the shades depending on the thickness of the enamel. (Restor Dent Endod 2012;37(2):84-89)

건설 프로젝트에서 D-virus가 안전에 미치는 영향에 관한 기초적 연구

송진우,표영민,진유나,이상범,김정길 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2

Construction site has contributed to construction productivity improvement by utilizing information, simplification, and standardization concept. Also it has contributed to quality and productivity improvement by standardizing design and construction process, using them to a fair decision-making process by organizing diverse data in construction process. However, construction process has diverse variables and uncertain case due to particularity in construction. These parts have an effect on construction process. To use unorganic construction information and knowledge properly has become the factor to project success. Therefore, this study analyzes that D-virus of the uneasy factors has an effect on safety control of construction industry. That is to say, aim of the study is to suggest the solution to remove those after confirming for these factors to have certain effect in construction process through fact finding survey and retesting the factors of D-virus to refer in business management in a constructive position.

울타리 고둥, Monodonta labio의 생식주기

송영보,이치훈,나오수,이영돈 濟州大學校 海洋硏究所 2002 해양과환경연구소 연구논문집 Vol.26 No.-

1995년 9월부터 1996년 8월까지 제주대학교 해양과 환경연구소가 위치한 함덕연안 조간대에서 채집한 울타리고둥, M. labio의 생식주기를 조사하기 위하여 생식소숙도지수의 변화와 생식세포 형성과정을 조직학적방법으로 조사하였다. 1. 울타리고둥의 생식소는 패각내 나선상 육질부 하단에서 꼬리돌기까지 간장부의 표면에 위치 하였다. 생식소가 성숙하면 암컷은 짙은 녹색, 수컷은 유백색을 띠고, 방출 후에는 암컷은 연갈색, 수컷은 연황색을 나타내었다. 2. 생식소숙도지수(GSI)는 암컷과 수컷 모두 수온이 상승하는 4월부터 상승하기 시작하여 9월에 암컷 0.47, 수컷 0.42로 최고치를 보이고 이후 10월부터 급격히 감소하였다. 저수온기인 1월에 GSI는 암컷과 수컷 모두 0.07로 최저치를 보였다. 3. 생식소의 발달 단계는 분열증식기(3월∼4월), 성장기(4월∼7월), 성숙기(8월∼9월) 그리고 방출 및 회복기(10월∼1월)의 연속적인 주기로 구분 할 수 있고, 주산란 시기는 10월로 추정 된다. 4. 울타리고둥, M. labio은 자웅이체로서, 성비는 약 1:1이었다(P>0.05). Reproductive cycle of thick liped monodont. Mondonta labio was invetigated by the histological observation of gonads and the gonadosomatic index(GSI). The thick liped monodont were collected at the intertidal zone of Hamdeok in Jeju-do from September, 1995 to August, 1996. Gonad of them was located o the surface of the liver below the stomachal caecum posterior spiral meat part of the shell. GSI value began to increase from May(as water temperature increased) and reached it's maximum value in September both male and female which were 0.42 and 0.47, respectively. It began to decrease from October thereafter, maintaining relatively in low value from January to March. The reproductive cycle of this species could be classified into four successive developmental stage; multiplication stage(March to April), growing stage(April to July), mature stage(August to september), spent and recovery stage(October to January). The main spawning period of M. labio appeared in October. The top shell, M. labio appeared to be gonochorism, neither sex reversal nor hermaphroditism. The sex ratio was approximately 1.0 : 1.0(P>0.05).

개에서 발생한 동맥관개존증 치료 증례

조나영,박성준,최호정,정성목,송근호 忠南大學校 獸醫科大學 附設 動物醫科學硏究所 2012 動物醫科學硏究誌 Vol.19 No.1

A Bicon Frise (7-month-old, intact female, B.W.: 3.5kg) was referred to the Veterinary Medical Teaching Hospital of Chungnam National University with the history of the murmur which was picked up during routine vaccination. The grade 3 of continuous murmur was identified on the auscultation. In the thoracic radiography, descending aorta and main pulmonary artery were enlarged and vertebral cardiac scale (VHS) was 10. In the echocardiography, turbulent and continuous positive flow was identified in the pulmonary artery at the right parasternal short axis view. We found the patent ductus arteriosus (PDA) connected the main pulmonary artery with the aorta by CT image. So, the diagnosis of PDA was made. The continuous murmur was not identified on the auscultation after surgical correction was achieved by ligation of PDA.

전자상거래의 보안과 전자결제에 관한 연구

나현식,송영하 호남대학교 정보통신연구소 1997 정보통신연구 Vol.7 No.-

전자상거래에 있어서 필요한 여러 가지 기술 중에서도 구입한 상품의 대금을 지불하고 이를 결제하는 기술은 금전과 관련된 문제이기 때문에 그 안전성과 정확성이 필수적으로 요구된다. 암호화된 신용카드나 전자화폐와 같은 전자 대금 기술들을 구현하려면, 보안이 보장되는 암호화 기법을 통해 통신망에서의 지불 및 개인정보 보안 문제를 해결하는 것이 중요하다. 본 연구에서는 전자상거래에 필요한 암호화기술과 보안 소프트웨어를 고찰하고, 전자상거래를 위한 결제시스템의 기술과 서비스, 그리고 보안기술에 대해서 기술하고자 한다. In order to complete electronic commerce, there are many technologies required. Among of these, it is very important to pay products which bought before and transfer by digital payment are related to money because of security and accuracy. Digital Cash is a kind of payment which to used cash in the real business world and to protect a s personal information. It is exists different ways between payment and transfer scenario. For instance, in order to complete digital cash payment for security credit card and digital cash, firstly, it is very important to work out a communication line and a personal security through a method of password authentication. In this paper, we analysed products, which to buy a develop password software some considerable facts and to investigate the present conditions for password technology develop and service at the domestic market. After that, to obtain a present information about digital cash payment which to consider making encipher information and decryption throughout this study.

성형조건에 따른 무연탄계 활성탄의 세공특성

이송우,나영수,김도한,류동춘,최동훈,류병순,송승구 한국화학공학회 2002 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.40 No.1

본 연구는 무연탄으로 활성탄을 제조할 경우 성형이 세공특성에 미치는 효과를 고찰한 것이다. 3가지 다른 방법으로 활성탄(파쇄형 활성탄, 압축성형 활성탄, 압축성형 활성탄)을 제조하여 특성을 비교했다. 이중에서 25%의 콜타르와 7%의 물을 혼합하여 압출 성형한 활성탄이 비표면적, 세공부피, 그리고 경도에서 가장 좋은 물성을 나타내었다. 압축 및 압출 성형체의 표면은 무연탄 원탄과는 달리 무연탄 분말이 바인더와 혼합되어 있으므로 매우 거친 상태를 나타내었고, 활성화시 거칠게 형성되어 있는 입자사이로 활성화제인 수증기가 쉽게 침투하여 많은 세공을 형성시킴을 알 수 있었다. 이렇게 형성된 세공을 통해 수증기 활성화반응이 잘 일어나 직경 3,000-50,000Å 범위의 거대세공이 발달하였다. 파쇄형 활성탄에 비해 약 2배의 거대세공(macropore)부피를 가지고 있었으며 경도도 30%에서 95% 이상으로 상승되었다. This study was to investigate the effect of granulation process on pore characteristics in manufacturing anthracitebased activated carbons. The activated carbons were made by three different methods to compare characteristics: the crushed activated carbon, the compressed activated carbon, and the extruded activated carbon. Among these activated carbons, the extruded activated carbon using a binder that consists of 25% coal tar and 7% water showed the best characteristics in specific surface area, pore volume, and hardness. Since the compressed and the extruded substances had coarser surfaces than a raw material, steam could penetrate easily through particles and produce macropores especially in the diameter ranges of 3,000-50,000Å during activation process. The extruded activated carbon showed about twice more macropore volumes than the crushed activated carbon and the hardness was increased from 30% up to 95%.

미생물 초기부착과 생물막 성장에 미치는 기질의 C/N 비

박영식,이석렬,나영수,서정호,송승구 부산대학교 환경문제연구소 1997 環境硏究報 Vol.15 No.1