• 제목/요약/키워드: Economical conditions

검색결과 628건 처리시간 0.024초

수중에서 금속 촉매의 니트릴 수화 반응에 의한 환경친화적 아미드 합성 (Environmentally Friendly Synthesis of Amide by Metal-catalyzed Nitrile Hydration in Aqueous Medium)

  • 무하마드 아십 후세인;김정원
    • 공업화학
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    • 제26권2호
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    • pp.128-131
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    • 2015
  • 친환경적 조건에서의 니트릴의 수화 반응은 아미드를 생산하기 위한 가장 경제적이고 매력적인 방법이다. 고체 금속 산화물과 지지체를 이용한 전이 금속 촉매 시스템은 이러한 니트릴 수화 반응을 보다 향상시키기 위한 의미 있는 연구로써 수행되어져 왔다. 이들 촉매들의 중요한 특징은 방향족, 지방족, 이종 원자형, 지방족 고리형 등의 니트릴들을 포함하는 넓은 범위의 다양한 기질들에 적용된다는 것이다. 또한 이들은 높은 촉매적 활성을 유지하면서 여러 번의 재사용성이 가능하고 반응 후 그 혼합물로부터 분리가 용이하다는 장점들을 갖는다. 이 리뷰를 통하여 니트릴 수화반응을 통한 아미드 합성에 적용되는 금속 산화물과 지지체를 가진 금속 촉매들에 대해 알아본다.

염료감응형 태양전지의 염료 착색 온도의 영향에 관한 연구 (The effect of dye coloring temperature on the dye-sensitized solar cells)

  • 이경준;서현웅;손민규;김정훈;김희제
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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    • pp.422-424
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    • 2008
  • A serious problem of the 21st century is the supply of energy resources. Reserves of fossil fuels are facing depletion: renewable energy resources must be developed in this era. Dye sensitizedsolar cells(DSC) have been very economical and easy method to convert solar energy to electricity. DSC can reach low costs in future outdoor power applications. However, to commercialize the DSC, there are still many shortages to overcome. When the DSC is commercialized in the near future, the productivity is an important factor. In the process of soaking in a dye, it usually takes $12\sim24$ hours. In this study, we varied the dye coloring temperature from $0^{\circ}C$ to $60^{\circ}C$. At the temperature of $40^{\circ}C$, DSC cell showed the best performance. We also expect the reduction of the time soaking in a dye. Counter electrode surface of DSC is deposited by RF magnetron sputtering under the conditions of Ar $2.8{\times}10^{-3}$ torr, RF power of 120W and substrate temperature of $100^{\circ}C$.

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Analytical Studies for SASW Measurements Underwater

  • Lee, Byung-Sik
    • 한국지반공학회지:지반
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    • 제13권3호
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    • pp.53-62
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    • 1997
  • 주파수영역 표면파기법 (SASW)을 수중지반탐사에 적용하기 위한 일련의 해석적 연구가 실시되었다. SASW실험으로 지반강도분포를 정밀히 예측하기 위해서는 실험조건, 고차모드의 영향, 응답파의 정리 기법 등, 실험결과에 영향을 미치는 모든 제반 요소들을 고려한 정확하고도 경제적인 이론분산곡선을 결정해야만 한다. 따라서, 본 논문에서는 수중 표면파의 이론분산곡선을 구하기 위한 해석기법들을 개발하고 그 이론적 배경을 설명하였다. 또한, 개발된 해석기법들을 수중지반에서 실제로 실시된 SASW실험결과의 분석에 적용하여 수중지반의 강도특성을 예측하는 예를 보였다. 이 결과로부터 개발된 해석기법들과 더불어서 수중지반탐사를 위한 SASW 실험방법의 적용성이 검토되었다.

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부식촉진에 의한 해양.항만 철근 콘크리트 구조물의 철근 방식에 관한 실험적 연구 (Rapid Corrosion Test on Marine Reinforcing Steel)

  • 정근성;문홍식;송호진;이상국;정영수
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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    • pp.537-542
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    • 2001
  • Recently long-span bridges, such as Kwang-Ahn Grand bridge, Seo-Hae Grand Bridge, Young-Jong Grand Bridge, etc, have been designed and constructed near the shore. It needs to maintain the durability of marine concrete structures which are exposed to severe chloride environments. It is well known that corrosion of reinforcement steels in concrete structure is the most important cause for the durability of concrete structure which can be controlled by systematic preparatory corrosion protection works for economic and safe infrastructures. Various corrosion protection systems have been used for the corrosion protection of reinforcement steels from detrimental chemical components such as chloride, sulphate and etc. Since chloride can be penetrated into concrete in a variety way, an effective method has to be adopted by taking into full economical aspects and technical data of each protection system. The objective of this experimental study is to investigate the corrosion behavior of reinforcing steel in laboratory concrete specimens which are exposed to cyclic wet and dry saltwater, and then to develop pertinent corrosion protection system, such as corrosion inhibitors and cathodic protection for reinforced concrete bridges exposed to chloride environment. Resistance of various corrosion inhibitors and impressed current system have been experimentally evaluated under severe environmental conditions, and thus effective corrosion protection systems could have been Practically developed for future concrete construction.

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스트럿-타이 모델을 이용한 프리스트레스트 더블 T형 보의 정착부 거동 연구 (A Study on Behavior for Anchorage Zone in Prestressed Double T Beam Using Strut-Tie Model)

  • 김종욱;이두성;민창식
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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    • pp.425-430
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    • 2002
  • This thesis is a study on behavior for anchorage zone in prestressed double T beam using strut-tie model. Stress conditions of Anchorage zone in prestressed double T beam are very disturbed because large concentrated forces act on relatively small areas. Hence, anchorage zone must be considered in Design of prestressed double T beam. If irrational design or irrational construction be conducted, that may lose stability in capacity as structure. In current design practice, certain parts of structure are designed with extreme accuracy, while anchorage zone in prestressed double T beam is designed using common sense, and experience. Therefore, it is generally very conservative. For that reason, logical, reasonable concept and accuracies are desired at design of anchorage zone in prestressed double T beam. Strut-tie method satisfies those desires. In this thesis, anchorage zone in prestressed double T beam is analyzed by considering prestressing forces. Strut-tie model is constructed based on principle stress trajectory obtained from 3D-finite element analysis in anchorage zone, and amounts of reinforcement be obtained. Results of analysis are compared with the way used in current design practice, and this thesis presents that strut-tie model can be an economical design than current design methods without losing the degree of safety.

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소도시 재래시장의 공간분석 - 충남 홍성읍 재래시장을 중심으로 - (Analysis of Space characteristics of Conventional Market in Small Town)

  • 한종구;박동소
    • 한국농촌건축학회논문집
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    • 제13권4호
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    • pp.43-50
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    • 2011
  • Activation of conventional market in small town is important in the reinvigoration of local economy as an economical center. The revitalization of local economy is closely related to the fosterage of conventional market. So the local government is trying to activate the market. However, the projects for the activation of conventional market are mostly centered on the modernization of facilities which is carried out at urban districts. Those facilities-centered plans, being carried out at urban district, lack the consideration of the peculiarities of rural districts and the regional conditions of the conventional market in small towns. And some projects for the modernization of facilities produce negative results. Especially the conventional market in small town shows a spatial structure of a five-day market and a market place and it was influenced by the spatial relationship between the permanent market and periodic market. So analyses on the spatial lay-out and form, store facilities, spatial distribution of types of business, spatial utilization on market place are needed to improve the physical environment of the conventional market. In this context, the study analyzed systematically the space of an old and lagged Hongseong conventional market located in central district of a small town. And It is expected that the results use as a basic data to establish effective space improvement plan for conventional market in small town.

전자해도 상의 항해계획 알고리듬 구현에 관한 연구 (On the Implementation of Route Planning Algorithms on the Electronic Chart System)

  • 위승민;김시화;장일동
    • 한국항해학회지
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    • 제24권3호
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    • pp.167-176
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    • 2000
  • The -advent of electronic navigation equipment and trustworthy computer which provides people with convenience made the management system by one-man bridge operation or the least people who are needed possible through the integration of communication network with various navigation equipment and related institution. One of the most needed ultra-modem navigation device for a mate, ECDIS is a core equipment for navigation in ENS that notifies peril to mate as well as supervises all tasks in hydrographical chart, voyage planning, course monitoring and voyage recording. We should make coast and ocean voyage planning first, for the secure navigation which is considering the course circumstances and next, for the reduction of voyage dates in economical aspect. There needs a thoughtful consideration about the feature of the ship itself and the course with weather condition in taking up the course and also we have to take into accounts about appropriate distance between ships. Considering the essential conditions of ECDIS the indispensable device in the future, it was developed the basic principle for voyage planning algorithm for officer and programmed to real implementation available. In this paper including most of the requirements in ECDIS performance standard I mentioned about such a basic and a core Principle with real application by using the Visual C++ programming language. The voyage plan includes the function that indicate and modifies all the way points in the course from department port to arrival port with erasing the wrong way points. Also, it provides in a document form that shows ETA at glance in average speed sailing.

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디지털 타이머를 이용한 인터넷 기반의 원격제어 및 모니터링 (Internet Based Remote Control and Monitoring System using Digital Timer)

  • 이양규;강신영;김은주;박철수;임영철;김광헌
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2001년도 추계학술대회 논문집
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    • pp.83-88
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    • 2001
  • This paper deals with the economical equipment control which is used by internet network system at the industrial workplace. If the control devices can be accessed by internet, we can have the developed possibility of work conditions. In this paper, we presented the advanced digital timer which has a communication function to control and observe panel to realize control solution based on internet to be easily applicable at workplace with low cost. and we used 485 serial communication module to have parallel expansibility and safety. And, this system was experimented and designed for easy system management and status check from remote station through internet As the result of experiment, the circuit configuration would be more simplified than the existing, and it is expected that multi connection control and monitoring can be simply implemented with low cost equipment at industrial workplace.

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노인 주거환경의 개념과 유형화 연구 (A Study on the Concept of Elderly Housing Environment and Housing Types)

  • 김민수;이성미;이유진;이연숙;이선민
    • 한국실내디자인학회:학술대회논문집
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    • 한국실내디자인학회 2006년도 춘계학술발표대회 논문집
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    • pp.224-228
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    • 2006
  • Recently, In Korea, diverse elderly facilities have increased by geometric progression cope with rapidly aging society. But, there haven't been enough systematic understanding about elderly housing. To approach the concept of elderly housing, the clear theory of its definition and types should be established. Thus, the purpose of this study is to set up the concept of elderly housing and clear definition, and to recreate criteria fit our situation. This study was proceeded by contents analysis of elderly housing environment in prior research. First, we understand the use of terms about elderly housing in references and redefine. Then, analyze the cases of categorizations in developed countries. Finally, the research point out current problems and make criteria in housing environmental aspects. This study leads new perspective to consist synthetic services according to special conditions of elderly, far from the economical point of view. It will contribute to understand elderly housing designing aging friendly environment.

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재료 융합 단계와 임시 스트럿의 경계조건을 이용한 기둥-보 강결 구조물의 효율적인 거동 연구 (A Study for Efficient Behavior of Beam-column Joint Structure Using Material Convergence Section Stage and a Temporary Boundary Condition by Strut)

  • 조재형;송재호
    • 한국산업융합학회 논문집
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    • 제23권2_2호
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    • pp.361-374
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    • 2020
  • Recently, small and medium-sized rahmen-type bridges have been developed as a technology that ensures the stability of structural behavior and the safety of use at the same time by using efficient and economical materials that make up the convergence section of reinforced bar, structural steel and concrete. This study is about a rahmen-type structure applied with the installation and dismantling of the strut. It improves the serviceability of the structure by forming multi-points and efficiently applies the convergence section of structural steel and concrete materials to the structural system changes to induce the displacement improvement effect additionally. By constructing mock-up models for the beam-column joint, the displacement was calculated and compared, and this was compared and analyzed by numerical analysis. The final displacement showed an improvement effect of 13.46% to 36.28% based on the vertical displacement of the existing structure without struts through the experiment of the mock-up models. As a result of analysis by numerical analysis method, the displacement improvement effect of 42.89% could be derived.