• Title/Summary/Keyword: Dip

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Dip-coating법에 의한 ${alpha}-Fe_2O_3$막 제조에 관한 연구 (A study on the preparation of ${alpha}-Fe_2O_3$films by dip-coating method)

  • 강경원;정용선;현부성;오근호
    • 한국결정성장학회지
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    • 제8권2호
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    • pp.292-298
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    • 1998
  • 출발원료로 ferric nitrate, ethylene glycol, acethyl acetone 혼합용액을 사용하여 dip-coating된 ${\alpha}-Fe_2O_3$ 막을 제조하였다. coating을 위한 혼합용액의 시간 경과에 따른 용액내의 가교(polymerization) 효과를 관찰하기 위해서 적외선 분광기(FT-IR)를 사용하였고, 막 형성시 유기물 분해 및 결정화 시작온도를 확인하기 위하여 FT-IR, XRD, DSC 등을 이용하여 분석을 행하였다. 또한 AFM과 SEM을 통하여 각 조건에서 제조된 막의 표면상태 및 두께 변화에 대하여 관찰되었다.

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물질순환모델을 이용한 제주항의 수질관리(III) - 오염부하의 정량적 관리 - (Water quality management of Jeiu Harbor using material cycle model(III) - Quantitative Management of Pollutant Loadings -)

  • 조은일;강기봉
    • 한국환경과학회지
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    • 제12권3호
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    • pp.307-317
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    • 2003
  • In this study, the material cycle model was applied to suggest alternative management of water quality for Jeju Harbor. The distribution of COD, DIN (dissolved inorganic nitrogen) and DIP (dissolved inorganic phosphorus) concentrations was reasonably reproduced by simulations on the model area of the Jeju Harbor using a material cycle model. The simulations of COD, DIN and DIP concentrations were performed under the conditions of 20∼100% pollution loadings reductions from pollution sources. In case of the 100% reduction of the input loads from Sanzi river, concentrations of COD, DM and DIP were reduced to 39%, 78% and 52%, respectively at Jeju harbor. In contrast, in case of the pollutant loadings reductions from sediment, the effect of DIN and DIP reduction relatively seemed to increase around the center of study area. The 95% reduction of the pollutant loadings from river and sediment is required to meet the COD and nutrients concentration of second grade of ocean water quality criteria.

임상가를 위한 특집 2 - Early loading의 난제 stability dip, 어떻게 극복할 것인가? (Stability dip, the obstacle of early loading protocol, how can it be figured out?)

  • 박창주
    • 대한치과의사협회지
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    • 제51권4호
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    • pp.198-203
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    • 2013
  • Nowadays, it seems like that the concept of the early loading protocol has been intruded between the concept of the immediate loading supported by advanced clinicians and the concept of the conventional loading supported by the prudent clinicians. In particular, the stability dip, which is found to occur usually at 4~6 weeks after dental implant placement because the decrease of the primary mechanical stability is not compensated by the increase of the secondary biologic stability, is frequently pointed out as one of the major causes of early loading failure. In this article, based on our recent clinical investigation about the crestal bone preservation effect of the early loaded NanoTite$^{TM}$ Tapered Certain Prevail$^{(R)}$ (Biomet 3i, USA), the concept of the early loading is revisited. In addition, various methods to overcome the stability dip are reviewed as the oral and maxillofacial surgeon's view point.

GIS와 지구통계학을 이용한 충주호 남부지역의 광역적인 사면안정평가 (Regional Evaluation of Slope Stability by Using GIS and Geostatistics Around the Southern Area of Chungju Lake)

  • 문상기
    • 자원환경지질
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    • 제33권2호
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    • pp.117-128
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    • 2000
  • Regional evaluations of slope stability by the failure criterion and by environmental geological factors were conducted. The failure criterion is the general conditions for plane failure which consider the geometrical conditions between geological discontinuities and topographical slope planes. The factor focused in this condiction is dip and dip direction. Geostatics, named semivariogram was used for establishing structural domains in slope stability evaluation by the failure criterion. The influential range was calculated to 6 km in the case of dip direction of dominant joint set and 7 km in the case of dip of the same dominant joint set. Then applying this failure criterion to the study area produced a slope stability map using the established domains and slopes generated by TIN module of ARC/INFO GIS. This study considered another regional slope stability analysis. 5 failure-driven factors 9the unstable slope map, geology, engineering soil, groundwater, and lineament density) were selected and used as data coverages for regional slope stability evaluation by geoenvironmental factors. These factors were weighted and overlayed in GIS. From the graph of cumulatave area (%) and instability index, finding critical points classified the instability indices. The most unstable slopes are located in the southern area of Mt. Eorae, Dabul-ri, and the eastern area of Junkok-ri in the first area is plane failure. Also, the expected orientations of failure are 59/338 and 86/090 (dip/dip direction).

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Comparison of Water Quality According to Seasonal Variation in Mokpo and Wando Costal Areas

  • Kim, Woo-Hang;Lee, Young-Sik
    • 한국환경과학회지
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    • 제17권3호
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    • pp.269-273
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    • 2008
  • The objective of this study was to evaluate the relationship between nutrients and phytoplankton. This study was done by the comparison to two costal areas Mokpo, which inflow fresh water, and Wando. In August, salinity of the sea water decreased by 3.5-4.5%o in Mokpo coastal area, but was not nearly decreased in Wando coastal area. This suggests a lot of fresh water inflow in Mokpo coastal area. DIN and DIP were decreased by water temperature increasing in Wando. However, in Mokpo, DIN and DIP were increased greatly during the summer season. Nitrogen was limited to a 10 NIP ratio especially during the summer season in Wando coastal area while phosphorus in Mokpo coastal area was limited with over 28 N/P ratio in all the seasons. Coefficient of determination$(r^2)$ between DIP and Chl.-a was 0.91 in Mokpo coastal area. On the other hand, Coefficient of determination$(r^2)$ between Chl.-a and DIN, DIP were 0.93 and 0.89, respectively, in Wando coastal area. These results suggest DIP in Mokpo and DIN and DIP in Wando might be limited at the increase of phytoplankton.

Tunnel Mapper를 이용한 Tunnel 막장면 조사에 관한 연구 (Study of Tunnel Face Mapping Using Tunnel Mapper)

  • 곽노경;조성진;이송
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 추계 학술발표회 2차
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    • pp.200-211
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    • 2010
  • Tunnel Mapper, which is tunnel face survey system was used to conduct Face Mapping on the face of the tunnel that is under construction. Then, accuracy and utility value on the forecast of discontinuity were verified to verify the field application in order to present the measures for the use of the system for conducting research on the discontinuity. As result of the directivity verification following discontinuity‘s project, forecasted measurement and actually researched measurement error for the Dip direction and Dip angle was less than ${\pm}10$. Accuracy was 82.6% for Dip direction and 90.7% for Dip angle, which are high. Accordingly, face research discontinuity forecasting system's reliability level towards directivity is high. Tunnel Mapper, a tunnel face survey system can be leveraged to replace face's visual survey and to obtain objective information, enabling execution of the survey system that can automate face survey going beyond time and space related limitations.

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한국전력 노후 가공송전선의 동적송전용량에 대한 재평가 (A Reassessment for Dynamic Line Rating of Aged Overhead Transmission Lines in Kepco's Network)

  • 김성덕
    • 조명전기설비학회논문지
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    • 제24권10호
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    • pp.123-129
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    • 2010
  • During the past 2 decades, many electric power companies have been searching various solutions in order to supply power with economical and more efficiency in the present transmission utilities. Most interesting method to increase the line capacity of overhead transmission lines without constructing any new line might be to adapt Dynamic Line Rating(DLR). Specified rating is normally determined by any current level, not by conductor temperature. Although specified rating is essential to design transmission line, dip may be the most important factor in limiting transmission capacity. Transmission lines built by the oldest dip criterion among the 3 different design criteria for conductor dip are nearly over one-half of all Kepco's transmission lines. This paper describes an up-rating method for those transmission lines in order to apply DLR technique. Based on limit dip conductor temperature and current of the transmission lines, limitation performance and effectiveness in applying DLR with weather model are analyzed. As a result of analysis, it can be shown that an improved method could be effectively used for increasing the line rating of old transmission line which was built by the design criterion with low dip margin.

영산강 하구해역에서의 단순 박스모델에 의한 물질수지 (Material Budgets in the Youngsan River Estuary with Simple Box Model)

  • 이경식;전수경
    • 한국해양환경ㆍ에너지학회지
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    • 제12권4호
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    • pp.248-254
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    • 2009
  • 영산강 하구해역에서 계절별로 물질순환과 영양염 플럭스 특성을 파악하기 위해 단순 박스모델을 이용하여 담수수지, 염분수지, 영양염 물질수지를 산정하였다. 외해, 시스템영역으로 유입되는 계절적 평균담수의 양은 $36.481{\times}10^6{\sim}663.634{\times}10^6m^3/month$로 나타났다. 염분수지에 의해 계산된 담수존재량은 $2.515{\times}10^6{\sim}5.812{\times}10^6m^3$이었고 평균 체류시간은 0.26~2.03일로 계산되었다. 평균체류시간은 계절별로 큰 차이를 보였는데 강우가 집중된 하계 풍수기에는 0.26일의 짧은 체류시간을 보인 반면 추계 갈수기에는 2.03일의 평균체류시간을 나타내었다. 해수교환량은 $1,248{\times}10^6{\sim}9,489{\times}10^6m^3/month$으로 하계 풍수기에 해수교환량이 가장 크게 나타났다. 영양염의 부하량은 DIP과 DIN가 각각 2.9~61.22 ton/month, 76.63~1,149.91 ton/month로 계산되었다. 영양염의 체류시간은 DIP의 경우 0.45~1.10일의 범위를, DIN의 경우 0.28~1.92일의 범위를 보였고, 담수체류시간과 비교하면 DIP과 DIN는 하계를 제외한 전 계절에서 담수 체류시간 보다 짧은 체류시간을 보여 영양염이 빠르게 순환되는 것을 알 수 있었다. 특히 DIP는 동계에 외해에서 상대적으로 높은 농도를 보이고 같은 시기에 해수교환에 의한 플럭스가 시스템 영역내로 유입되는 결과를 보여 외부 유입원 존재를 추정하게 하였다.

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MPEG-21 멀티미디어 프레임워크에서 툴 서버의 구조 및 기능 (The Architecture and Its Function of Tool server in MPEG-21 Multimedia Framework)

  • 김광용;홍진우;김진웅
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2003년도 추계종합학술대회
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    • pp.292-295
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    • 2003
  • MPEG-21 멀티미디어 프레임워크 환경에서의 툴 서버의 구조와 기능을 제안한다. MPEG-21의 목적은 멀티미디어 콘텐츠의 전자적 생성, 배포, 거래를 투명하게 이용할 수 있도록 상호 운용 가능한 멀티미디어 프레임워크를 제공하는 데에 그 목적이 있다. MPEG-21을 구성하는 주 요소로서 DIP(Digital Item processing)와 DIA(Digital Item Adaptation)가 있다. DIP의 역할은 디지털 리소스에 메타 데이터 정보를 구조화하여 표현할 수 있는 DI(Digital Item)를 생성하고 소비하는 기능을 가진다. DIA는 사용자가 터미널 또는 네트워크 특성에 맞게 고유의 DI를 적응시켜서 보내주는 기능을 한다. 툴 서버(Tool server)는 DIP 또는 DIA로부터 필요로 하는 구동 툴을 검색하여 적합한 툴을 제공해 주는 기능을 한다. DIA가 DI 자체를 사용자 요구에 맞게 적응시켜 소비시켜 주는 일을 한다면 툴 서버는 사용자 터미널 환경에 맞추어 DI를 생성 또는 소비하는데 적합한 소프트웨어 툴을 찾아서 다운로딩하고 생성 또는 소비할 수 있게 해 주는 기능을 한다. 전체 논문의 구성은 다음과 같다. 1장에서 MPEG-21 멀티미디어 프레임워크에서 툴 서버의 필요성과 역할을 알아본다. 툴 서버가 가져야 할 요구 사항은 2장에서 논한다. 3장에서는 툴 서버의 기본 구조와 각 모듈별 기능을 살펴본다. 그리고 3장에서는 툴 서버를 DIP 또는 DIA와 연동했을 때 상호간에 이루어지는 시나리오를 설명한다. 또한 시나리오를 토대로 간단히 테스트용 툴 서버를 구현한다. 마지막 4장에서 결론을 맺는다.

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Polypyrrole을 증착시킨 Poly(vinyl alcohol) 나노섬유 제조 및 전극용 텍스타일 센서로의 활용 가능성 탐색 -딥 코팅과 현장중합 증착 방식을 중심으로- (Fabrication of Polypyrrole Deposited Poly (vinyl alcohol) Nanofiber Webs by Dip-coating and In situ Polymerization and their Application to Textile Electrode Sensors)

  • 양혁주;김재현;이승신;조길수
    • 한국의류산업학회지
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    • 제22권3호
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    • pp.386-398
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    • 2020
  • This study compared dip-coating and in situ polymerization methods for the development of nanofiber-based E-textile using polypyrrole. Nanofiber webs were fabricated by electrospinning an aqueous poly (vinyl alcohol) (PVA) solution. Subsequently, the PVA nanofiber web underwent thermal treatment to improve water resistance. Dip-coating and in situ polymerization methods were used to deposit polypyrrole on the surfaces of the nanofiber web. An FE-SEM analysis was also conducted to examine specimen surface characteristics along with EDS and FT-IR that analyzed the chemical bonding between polypyrrole and specimens. The line resistance and sheet resistance of the treated specimens were measured. Finally, an electrocardiogram (ECG) was measured with textile sensors made of the polypyrrole-deposited PVA nanofiber webs. The polypyrrole-deposited PVA nanofiber webs fabricated by dip-coating dissolved in the dip-coating solution and indicated damage to the nanofibers. However, in the case of in situ polymerization, polypyrrole nanoparticles were deposited on the surface and inter-web structure of the PVA nanofiber web. The resistance measurements indicated that polypyrrole-deposited PVA nanofiber webs fabricated by in situ polymerization with an average sheet resistance of 5.3 k(Ω/□). Polypyrrole-deposited PVA nanofiber webs fabricated by dip-coating showed an average sheet resistance of 57.3 k(Ω/□). Polypyrrole-deposited PVA nanofibers fabricated by in situ polymerization showed a lower line and sheet resistance; in addition, they detected the electrical activity of the heart during ECG measurements. The electrodes made from polypyrrole-deposited PVA nanofiber webs by in situ polymerization showed the best performance for sensing ECG signals among the evaluated specimens.