• Environmental Engineering Research
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• 제22권2호
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• pp.169-174
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• 2017

Vacuum swing adsorption (VSA) is a promising treatment method for volatile organic compounds (VOCs). This study focuses on a VSA process for regenerating activated carbon spent with VOCs, and then investigates its adsorption capacities. Toluene was selected as the test VOC molecule, and the VSA regeneration experiments results were compared to the thermal swing adsorption process. Cyclic adsorption-desorption experiments were performed using a lab-scale apparatus with commercial activated carbon (Samchully Co.). The VSA regeneration was performed in air (0.5 L/min) at 363.15 K and 13,332 Pa. The comparative results depicted that in terms of VSA regeneration, it was found that after the fifth regeneration, about a 90% regeneration ratio was maintained. These experiments thus confirm that the VSA regeneration process has good recovery while operating at low temperatures (363.15 K) and 13,332 Pa.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.591-596
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• 2011

There are quite a number of business processes in the urban regeneration project. Managers and participants who involved in the project make and use information for the best way to perform in the particular business process. The information can be also reused and produced for data at the next stage. Accordingly, the information sometimes goes out of existence and work data up into new information when the urban regeneration project has been accomplished. But in that case some of changes happen occasionally, the business for urban regeneration has suffered a loss of profit and time as result of confusions about decisions and inappropriate action. For that reason, the information should be analyzed to achieve its aim at the business process under the influence of changes. Then, even though detail processes and management method change, the Core Information, which are important factors for accomplishing the project, help that the project can be operated to solve the problem about confusion and loss of the business. In conclusion, the Core Information is main effective factors for successful urban regeneration projects on the change management. The purpose of this study is to research the information according to the Information-flow and changes, and to find out the influence factors and the Core Information to manage efficiently at the process of urban regeneration projects.

• 한국해양공학회지
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• 제34권5호
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• pp.342-350
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• 2020

In this study, a hydrate inhibition system is investigated for shallow water gas fields. Mono-ethylene glycol (MEG) injection has been used as a typical method for inhibiting hydrate formation in gas fields; therefore, most offshore platforms are equipped with MEG injection and regeneration processes. A recent application of a kinetic hydrate inhibitor (KHI) has reduced the total volume of MEG injection and hence reduce the operating cost. Experiments are designed and performed to evaluate and verify the KHI performance for inhibiting hydrate formation under shallow water conditions. However, the shut-in and restart operation may require the injection and regeneration of MEG. For this operation, the MEG concentration must be optimized while considering the cost of MEG regeneration. The obtained results suggest that decreasing MEG concentration from 80 wt% to 70 wt% can reduce the life cycle cost (LCC) of MEG regeneration process by approximately 5.98 million USD owing to reduced distillation column cost. These results suggest that the hydrate inhibition system must be evaluated through well-designed experiments and process simulations involving LCC analysis.

• 한국환경보건학회지
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• 제27권4호
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• pp.9-14
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• 2001

This study was performed to develop the modified FGD(Flue Gas Desulfurization) process which can eliminate the possibility of generating secondary pollutants. Limestone was regenerated by adding ammonium hydroxide and carbon dioxide, and reusing it as a absorbent in FGD gypsum Process. A series of the new or modified FGD process which include desulfurization and regeneration limestone from CaSO$_3$. 1/2H20 and CaSO4 . 2H2O, were carried out under various experimental conditions. The results showed that the optimum injection ratio for regeneration of limestone was 0.3 ml/min of CO2 flow rate, 2 ml of NH4OH per 0.01 M of regent grade CaSO4 . 2H20O and the optimum regeneration temperature was 50. The increaser was the number of times of limestone regeneration, the faster was the breakthrough point of desulfurization at the desulfurination process which the regenerated limestone was used. Then the efficiency of desulrurization was decreased. This study can be confirmed the possibility for reuse of regenerated limestone due to the similarity of desulfurization characteries both reagent grade calcium carbonate and regenerated calcium carbonate. Finally, it appeared that the new technology using regenerated 1imestone can be applied to the FGD process.

• Bulletin of the Korean Chemical Society
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• 제18권8호
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• pp.811-814
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• 1997

An oxidative thermal regeneration process was developed and evaluated for its potential applicability in several environmental areas. The feasibility of the process is affected strongly by the gradual carbon loss, energy consumption, physical changes of carbon, and effective destruction efficiency of adsorbed materials during the regeneration. The aim of the study is to determine the optimum conditions to maintain acceptable destruction efficiency for adsorbed organics, controlling oxidant flow rate. Prior to its applications, various preliminary tests were carried out to determine the effects of experimental parameters on the process. The tests performed were reaction temperature, carbon loss, surface area, surface structure, and adsorptive property. The results of these tests show that the parameters are dependent on oxidant flow rate, and suggest that the process is comparable and, in some ways, possibly superior to conventional regeneration techniques because the oxidative process is a single step and less energy intensive.

• 한국건설관리학회논문집
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• 제11권4호
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• pp.41-50
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• 2010

1960~70년대 도시의 무분별한 개발로 2000년대에 들어 도심은 공간 활용을 높이는 개발이 필요로 하게 되었다. 이에 2003년 도시 및 주거환경정비법이 개정되어 이전의 도심재개발사업 등이 도시환경정비사업으로 바뀌어 진행 되고 있다. 최근의 도시환경정비사업은 대형화 복합화의 대규모 사업으로 진행되고 있다. 이러한 사업은 다양한 참여 주제자, 이해관계자, 사업시행자 등 사이의 원활한 의사소통을 중요시 하고 있으나 표준화된 업무 절차가 없어 어려움이 있다. 이에 본 연구에서는 도시환경정비사업 중에 조합방식의 절치를 분석하고, BPMN(Business Process Modeling Notation) 모델링 방식을 통해 도식화하여 다양한 참여 주체자들에게 공통의 업무프로세스 모델을 제시함으로써 참여 주체자들이 절차를 쉽게 파악하고 이해할 수 있을 것으로 기대한다. 더 나아가 의사소통을 원활하게 하고 사업의 참여도를 높여 사업 기간을 단축하는 효과를 얻을 수 있을 것이다.

• 청정기술
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• 제23권2호
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• pp.140-147
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• 2017

본 연구에서는 연료전지용 디젤 흡착 탈황 반응기에 사용된 촉매를 재생하는 공정을 수치해석을 통해 모사하고 분석하여 관련된 기초 공정 정보를 도출하였다. 촉매 재생에 사용되는 질소 퍼지가스의 유량, 충전된 탈황촉매의 투과율, 반응기의 크기, 반응기의 단열 성능에 따른 정상상태 해석을 통해 각각의 요소가 촉매 재생에 미치는 영향들을 살펴보았다. 온도의 영향을 거의 받지 않았던 탈황공정과 달리 촉매의 재생 공정에서는 온도 변화에 따라 영향을 크게 받았으며 이전 탈황 연구에서 중요한 공정 변수였던 충전된 촉매의 투과도, 충전층의 공극률 등은 큰 영향을 미치지 못했다. 비정상상태 해석을 수행하여 재생에 소요되는 시간을 예측하였으며 퍼지가스의 유량과 온도를 변화시키며 재생에 소요되는 시간을 분석한 결과, 퍼지가스의 유량을 높이는 것 보다 온도를 높이는 것이 재생에 더 효율적임을 확인하였다. 본 연구 결과는 선박 연료전지용 디젤의 흡착 탈황 반응기의 재생 공정 개발에 활용될 것으로 기대된다. 또한 본 결과는 연료전지뿐 아니라 일반적으로 정유사에서 생산되는 디젤유의 황 함유량을 감소시키는 저황 시스템 디자인에 활용될 수 있으며 이러한 의미에서 석유화학 산업의 청정화 기술 확보에 이바지할 것으로 기대된다.

• 대한설비공학회지:설비저널
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• 제15권2호
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• pp.169-181
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• 1986

A numerical analysis has been conducted on the dehumidification phenomena of rotary absorptive dehumidifier. Parameters that affect the dehumidification efficiency, such as regeneration temperature, humidity, rotor angular velocity, air flow rate and regeneration section angle are studied and optimum driving conditions are determined from the results, Furthermore three new types of dehumidification method are developed to improve the efficiency They are named MODE 2, 3 and 4, while the present one MODE 1. Cooling zone has been constructed between regeneration and process Bone in MODE 2 and as a result exit temperature of the process air decreases. MODE 3 an improvement of MODE 2, recirculates the cooling air into the regeneration zone and regeneration input as well as exit temperature decreases. In MODE 4, some of tee regeneration air is recirculated and it cuts down the regeneration input. Among them MODE 3, showed the best dehumidification efficiency.

• 한국건설관리학회논문집
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• 제13권3호
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• pp.3-13
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• 2012

1960년대 이후 국내의 도심은 수도권 중심의 개발로 인한 집중화, 과밀화, 기반시설의 노후화 및 상업 기능의 쇠퇴 등 사회, 경제, 환경적 문제들이 발생하였으며, 2000년대 들어 각종 도시 문제를 해결하기 위해 도시재생사업이 대두되었다. 그러나 현재 도시재생사업은 다양한 용도의 복합화 시설을 추구하고 있으며 사업의 특성상 다수의 참여주체, 사업의 장기화 등으로 인해 업무 프로세스가 복잡해지고 있다. 이런 현상으로 수행업무가 체계화되지 못해 사업 참여자들은 사업을 진행하는 데 있어 참여자간의 복잡한 이해관계, 업무협업 등의 어려움을 겪고 있다. 이러한 문제점을 해결하기 위해 여러 기관에서 도시재생사업 관련 정보 시스템을 제공하고 있지만 사업 세부내용을 체계적으로 제공하는데 한계가 있다. 이에 본 연구에서는 도시재생사업의 현황 및 업무프로세스를 분석하고 업무정보관리의 체계성의 필요성을 제시하였다. 또한 도시재생사업 업무정보 체계 정립을 위해 BPS(Business Process Breakdown Structure, 이하 BPS)의 개념을 도입하여 사업진행을 위한 업무 정보를 분류하고 체계화 하였다. 이를 토대로 BPS기반의 도시재생사업 업무정보 시스템을 구현하고 시스템의 사용성을 평가하였다. 본 연구를 통해 BPS기반의 도시재생사업 업무정보 시스템을 구축함으로써 사업 참여자들에게 체계적인 도시재생사업관련 업무정보를 제공하여 효과적인 사업을 진행하는데 도움을 줄 것이다.

• Animal cells and systems
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• 제16권6호
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• pp.462-468
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• 2012

Urodeles including newt and salamander have remarkable regenerative capacity during the postembryonic life span. Some of the unique features are the formation of the well-developed wound epidermis and the active dedifferentiation process in the early phase of regeneration. These are regarded as key events for the successful regeneration since no further regenerative activity is possible without them. In this study, we investigated the role of retinoic acid (RA) in salamander limb regeneration by blocking RA synthesis using disulfiram, an inhibitor of aldehyde dehydrogenase that oxidizes retinal to RA. Disulfiram treatment resulted in delaying the limb regeneration processes via inhibition of wound epidermis formation and dedifferentiation process. When RA was administered after disulfiram treatment, the inhibitory effect of disulfiram was rescued. In addition, disulfiram treatment after the dedifferentiation stage resulted in the mild retardation of limb regeneration, suggesting that RA might also be involved in the blastema outgrowth. Furthermore, salamander MMP-9 gene expression was also inhibited by disulfiram treatment. Collectively, our findings indicate that endogenous RA may play an important role(s) in the early phase of limb regeneration by regulating the expression of molecules responsible for the modification of intracellular and extracellular environment during salamander limb regeneration.