슬관절 골관절염 환자에서 AVOCADO/SOYBEAN UNSAPONIFIABLES (ASU)의 효과: ASU 단독치료와 ASU-Nasproxen 병용치료의 효과 및 위장관 부작용의 비교

김종화 ( C H Kim ),이동민 ( D H Lee ),김용성 ( Y S Kim ),최보금 ( B G Choi ),박주형 ( J H Park ),김신재 ( S J Kim ),이치국 ( C K Lee ),전현순 ( H S Jeon ),류완희 ( W H Yoo ),곽재용 ( J Y Kwak ),백홍선 ( H S Baek ) 전북대학교 의과학연구소 2001 全北醫大論文集 Vol.25 No.1

ASU 치료는 증상을 갖고 있는 슬관절의 골관절염 환자의 통증 개선과 관절 기능을 호전시키고, 약물투여 중지 후에 지속효과를 갖는 증상개선 약제로서 안전하게 사용할 수 있을 것으로 보인다. 소염진통제인 naproxen과의 병용치료와의 비교에서는 병용치료 군에서 효과의 발현시기와 전반적인 평가에서는 우월하였으나, 부작용이 보다 많이 발생하였다. 따라서 ASU를 골관절염의 약물치료의 한 방법으로 사용될 수 있을 것으로 보이며, 단순진통제 및 소염진통제 등의 약물 등과 같이 단일요법으로서의 사용과 다른 약물과의 병용치료의 효과 및 안정성에 대해서는 보다 많은 연구가 필요할 것으로 보인다. Objective: To compare the efficacy and safety between avocado/soybean unsaponifiables (ASU) alone and ASU-naproxen combination in the treatment of symptomatic osteoarthritis (OA) of the knee and to determine persistent efficacy after stopping medication and gastrointestinal tolerability. Methods: One hundred twenty-five patients with symptomatic OA of the knee were included in 20-week trial with 12-week treatment period and 8-weeks post-treatment follow-up. Efficacy was evaluated by Lequesne`s index (LI), pain score (VAS; visual analong scale. 10cm) at 4-week interval during the study and physician`s and patient`s global assessment at 20th week. Gastrointestinal side effects were evaluated by questionnaire for gastrointestinal symptoms and number of the ingested antacids during the study. Results: Sixty-three patients were received ASU alone, while sixty-two patients were received ASU and naproxen. Mean±SD scores of pain VAS score were reased from baseline at 8th and 12th weeks after medication in the former groups and 4th, 8th and 12th weeks in the latter groups. Mean±SD scores of LI were decreased from baseline at 12th week after medication in the former groups and 4th, 8th, 12th week in the latter groups. Both scores of LI and pain VAS were maintained at 8th week after stopping medication. The scores of LI and pain VAS scale were significantly decreased in combination group than ASU alone group at 4th and 8th weeks, but tended to lower in combination group at 12th week and post-treatment period. The improvement of physician`s global assessment was seen in 65.4% of combination and 53.2% of ASU alone group. The patient`s global assessment was similar to it. Twenty-six patients (20.8%) could not complete the 20-week study and the causes are different in two groups: side effects are more common cause in combination group and low efficacy and non-compliance were more common in ASU alone group. Gastrointestinal side effects are the most common adverse effects of the both groups, and the frequencies are more common in patients received naproxen as a combination therapy. Conclusion: ASU showed immediate and persistent efficacy in the treatment of patients with symptomatic OA of the knee. The combination of ASU and naproxen was more effective than ASU alone during the treatment period, but similar at post-treatment period. Gastrointestinal side effects were more frequent in combination group than ASU alone.

순산소 연소를 위한 초저온 공기분리장치의 엑서지 분석

최형철,문흥만,조정호 한국가스학회 2019 한국가스학회지 Vol.23 No.1

In order to solve the global warming and reduce greenhouse gas emissions, CO2 capture technology was developed by applying oxy-fuel combustion. But there has been such a problem that its economic efficiency is low due to the high price of oxygen gases. ASU is known to be most suitable method to produce large quantity of oxygen, to reduce the oxygen production cost, the efficiency of ASU need to be improved. To improve the efficiency of ASU, exergy analysis can be used. The exergy analysis provides the information of used energy in the process, the location and size of exergy destruction. In this study, the exergy analysis was used for process developing and optimization of large scale ASU. The process simulation of ASU was conducted, the results were used to calculate the exergy. As a result, to reduce the exergy loss in the cold box of ASU, a lower operating pressure process was suggested. It was confirmed the importance of heat leak and heat loss reduction of cold box. Also, the unit process of ASU which requires thermal integration was confirmed.

순산소 연소를 위한 초저온 공기분리장치의 최적공정 설계 연구

최형철 ( Hyeung-chul Choi ),문흥만 ( Hung-man Moon ),조정호 ( Jung-ho Cho ) 한국화학공학회 2018 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.56 No.5

지구 온난화 문제 해결과 온실가스 감축을 위하여 화력발전소를 중심으로 순산소 연소를 통한 CO₂ 포집 기술이 개발되었으나, 산소 생산 비용이 높아 경제성이 떨어지는 문제를 가지고 있다. 순산소 연소에 필요한 대량의 산소(>2,000 tpd)를 생산하는 방법은 초저온 공기분리장치(ASU: Air Separation Unit)가 가장 적합한 것으로 알려져 있으나, 대부분 고순도(>99.5%) 산소 생산에 최적화되어 건설되었다. 이런 초저온 공기분리장치에서 순산소 연소에서 사용이 가능한 낮은 순도(90~97%)의 산소를 생산하고 공정을 최적화할 경우, 공정 효율이 높아져 산소 생산 비용 절감이 가능하다. 본 연구에서는 순산소 연소 발전시스템에 산소를 공급할 수 있는 초대형(>2,000 tpd O₂) ASU 개발을 위하여 공정 분석 및 비교 평가를 수행하였다. 상용 프로그램인 AspenHysys를 이용하여 산소 순도에 따른 회수율 및 전력소모량을 계산하고 공정의 효율을 평가하였다. 그 결과 ASU를 통해 순산소 연소에 공급되는 산소는 약 95%가 최적이며, 생산 공정 최적화 시 약 12~18%의 전력소모량 절감이 가능한 것을 확인 할 수 있었다. In order to solve the global warming and reduce greenhouse gas emissions, it has been developed the CO₂ capture technology by oxy-fuel combustion. But there is a problem that the economic efficiency is low because the oxygen production cost is high. ASU (Air Separation Unit) is known to be most suitable method for producing large capacity of oxygen (>2,000 tpd). But most of them are optimized for high purity (>99.5%) oxygen production. If the ASU process is optimized for low purity(90~97%) oxygen producing, it is possible to reduce the production cost of oxygen by improving the process efficiency. In this study, the process analysis and comparative evaluation was conducted for developing large capacity ASU for oxy-fuel combustion. The process efficiency was evaluated by calculating the recovery rate and power consumption according to the oxygen purity using the AspenHysys. As a result, it confirmed that the optimal purity of oxygen for oxyfuel combustion is 95%, and the power consumption can be reduced by process optimization to 12~18%.

IGCC 플랜트에서 산소공급방식이 성능에 미치는 영향

안지호,김동섭 한국수소및신에너지학회 2012 한국수소 및 신에너지학회논문집 Vol.23 No.3

In this paper, two types of integrated gasification combined cycle (IGCC) plants using either an air separation unit (ASU) or an ion transport membrane (ITM), which provide the oxygen required in the gasification process, were simulated and their thermodynamic performance was compared. Also, the influence of adopting a pre-combustion CO2 capture in the downstream of the gasification process on the performance of the two systems was examined. The system using the ITM exhibits greater net power output than the system using the ASU. However, its net plant efficiency is slightly lower because of the additional fuel consumption required to operate the ITM at an appropriate operating temperature. This efficiency comparison is based on the assumption of a moderately high purity (95%) of the oxygen generated from the ASU. However, if the oxygen purity of the ASU is to be comparable to that of the ITM, which is over 99%, the ASU based IGCC system would exhibit a lower net efficiency than the ITM based system.

IGCC 가스화기 산소 공급 압력 안정화를 위한 ASU 공정 제어 방식 개선에 관한 연구

방기철,유정현,조현우,손영득 사단법인 한국융합기술연구학회 2023 아시아태평양융합연구교류논문지 Vol.9 No.8

IGCC (Integrated Gasification Combined Cycle) is an environmentally friendly and highly efficient energy source; however, it has high construction and maintenance costs, as well as operational complexity, leading to lower reliability. Since its completion in 2016, IGCC has improved its utilization rate to around 78% through efforts to stabilize its facilities. However, in order to achieve the target utilization rate of 85% set for IGCC, it is necessary to eliminate potential failure factors and minimize sudden shutdowns of the power plant. Currently, the potential issue with IGCC lies in the instability of gasifier load tracking, which is caused by the unstable oxygen supply pressure in ASU(Air Separation Unit), and it can lead to combustion instability, refractory material damage, and shortened equipment lifespan. Therefore, in order to address these problems, the causes of pressure instability and the drawbacks of existing control methods have been analyzed, and improvement measures have been proposed. These measures have been applied to the actual control system to validate their stabilization effects. IGCC(석탄가스화 복합발전)은 친환경, 고효율 에너지이지만, 건설비 및 유지비가 높고 설비 복잡성으로 인해 운영 신뢰도가 낮다. 국내 IGCC는 2016년 준공 이후 설비 안정화 노력을 통해 이용률을 78% 수준까지 향상시켰으나, IGCC가 목표로 하는 85% 이용률을 달성하기 위해서는 잠재적 고장요인을 제거하여, 돌발고장을 최소화해야 한다. 현재 IGCC의 잠재적 문제점은 가스화기 부하 추종 불안정이다. 이는 ASU(공기 분리 장치) 산소 공급 압력 불안정에 의해 발생되고 있으며, 연소 불안정, 내화재 손상, 기계 수명 단축 등을 유발할 수 있다. 따라서 이러한 문제를 해결하기 위해, 압력 불안정 원인과 기존 제어방식의 문제점을 분석하고, 개선방안을 제시하였으며, 실제 제어시스템에 적용하여 안정화 효과를 검증하였다.

플랜트의 구성을 고려한 IGCC용 가스터빈의 성능해석

김영식(Young Sik Kim),이종준(Jong Jun Lee),김동섭(Tong Seop Kim),손정락(Jeong Lak Sohn),주용진(Yong Jin Joo) 대한기계학회 2008 大韓機械學會論文集B Vol.32 No.9

Integrated gasification combined cycle (IGCC) is an environment friendly method of using coal. Several commercial IGCC plants have been built worldwide during the past decade, and a domestic development project has also been launched recently. Operation and performance characteristics of a gas turbine in the IGCC plant deviates from those of original gas turbines due to several factors such as increased amount of fuel supply and integration with other components. In this study, performance of a gas turbine in the IGCC plant is analyzed considering its integration with the air separation unit (ASU). Influence of the degree of integration (split of air supplies to ASU from the auxiliary compressor and the gas turbine compressor) on the system performance is investigated. In addition, effect of modulating nitrogen return flow from the gasifier to the gas turbine on the operating characteristics of the gas turbine is examined.

가상플랜트 기반의 최적설계 기술을 활용한 공기분리장치 설계 최적화

김주동(Joo-Dong Kim),최신범(Shin-Beom Choi),최재붕(Jae-Boong Choi),이홍철(Hong-Chul Lee),황인주(In-Ju Hwang) 대한설비공학회 2010 대한설비공학회 학술발표대회논문집 Vol.2010 No.6

Recently, plant design review by employing virtual plant is an important issue in the field of plant engineering. Especially, many researches for compactness and modularization were performed to reduce time, cost and space. So, the aim of this paper is development of design optimization techniques based on virtual plant for small-sized cryogenic plant such as ASU(Air Separation Unit). To do this, design optimized modules such as scale up/down, piping generation and navigator are developed by employing XVL(eXtensible Virtual world description Language). Finally, the availability of these modules is determined to apply the LNG(Liquefied Natural Gas) plant management system based on RAMS(Reliability, Availability, Maintainability and Safety) called as LPMS-RAMS. This result will be used to develop the web-based LPMS-RAMS.

ASU 와 연계를 고려한 IGCC 용 가스터빈의 성능 예측

박성구(Sung Ku Park),김유석(You Seok Kim),백민수(Min Su Paek) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.10

The construction plan of 300MW-class IGCC plant has been pushed ahead on the Taean thermal power plant site in Korea. The integration of gas turbine and air separation unit has a significant effect on the performance and the stability of the IGCC plant. In this paper, the influence of the integration with gas turbine and air separation unit has been analyzed using commercial code(GateCycle) and in-house code(visual Basic) for the process design of gas turbine and air separation unit, respectively. To achieve an acceptable surge margin of the gas turbine, the air extraction from compressor exit and the extension of turbine nozzle area were considered. As the extraction air from compressor increases, the surge margin also increases. Furthermore, it is expected to be able to secure surge margin through the extension of turbine nozzle area. If the turbine nozzle area increases by 19.4%, the surge margin is analyzed to be similar to a design surge margin of gas turbine for natural gas. The mass flow of extraction air is limited by the operation constraints such as turbine (rotor) inlet temperature and the allowable integration degree was predicted to be about 35%. At this integration degree, the power consumption of air separation unit and the integrated system efficiency were analyzed to be about 45MW and 31%, respectively.

퍼시발 로웰(Percival Lowell)의 구한말 한국 음악문화에 대한 인식

최희영 ( Choi Hee-young ) 한국음악사학회 2022 한국음악사학보 Vol.68 No.-

본 연구는 조선 보빙사를 보좌한 인연으로 고종에게 초청을 받아 1883년 12월부터 3개월간 조선에 머문 퍼시발 로웰(Percival Lowell)의 구한말 기생 및 예인집단, 그리고 이들의 공연에 관한 인식을 『조선: 고요한 아침의 나라 Chosön: The Land of the Morning Calm』(1885) 및 그가 직접 찍은 사진을 바탕으로 살펴보았다. 로웰은 오리엔탈리즘적 시각을 완전히 벗어나진 못했지만, 1882년 일본에 머물면서 오로지 자료 수집만을 통해 저술한 윌리암 그리피스(William Elliot Griffis)의 이전 서술과는 사뭇 달랐다. 로웰은 직접 경험을 바탕으로 기생의 노래나 예인집단 연행의 시각적, 음악적, 연극적 요소를 자신의 느낌을 중심으로 비교적 구체적으로 서술하였다. 외국인인 로웰에 대해 편안하고 친근하게 다가왔던 기생, 화기애애한 분위기의 악공ㆍ광대 집단, 추위 속에서도 관객을 위해 연주하는 취타수에 대한 인상 등이 그 예이다. 음악에 대해서는 구슬픈 곡조를 강조하면서 바로 이러한 면이 동양의 전통을 잘 보존하고 있음을 예증한다고 표현하였다. 악공 연주에 대해서는 악기 간 음색의 조화와 균형을 언급하였고 광대의 연기력에 대해서 큰 찬사를 보냈다. 제국주의 담론 영향 아래 동양의 문화를 미개한 것으로만 취급하던 당시 서양인들의 시각에서 벗어나 로웰은 조선의 고유한 문화 양식을 그 자체로 인정하는 문화상대주의적 시각을 보여주었다. This article investigates Percival Lowell’s perception of entertainers and musical cultures of late Chosŏn with a particular focus on his book, Chosön: The Land of the Morning Calm (1885) and photographs. Lowell stayed in Chosŏn for about three months beginning December 1883 at King Kojong’s invitation after working for the Chosŏn envoy sent to America. As the first American diplomat, coming with a camera, he is known to have taken the earliest portraits of the king, photographs of the inner sanctums of palaces, gardens and officialdom, and snapshots of street life in and beyond the capital’s gates. Analyses of his textual and visual materials reveal that Lowell had a positive attitude toward Korean musicians and music, although his points of view were still based on Orientalism. His descriptions of Korean musicians include the kindness of kisaeng, friendly atmosphere of akkongㆍkwangdae, and the enthusiasm of ch’wit’asu who is playing music even in the cold weather just for the audiences. With respect to their performances, he stressed that Korean music invoked plaintive and sad emotions, which, as he argued, would be the core characteristics of Far Eastern musical culture. He also mentioned harmonious instrumental music playing and excellent acting skills of kwangdae. Lowell’s descriptions of Korean music, in general, adopt a position of cultural relativism, distancing himself from other travelogues of the time that interpreted Asian culture from the imperial point of view.

IGCC를 기본으로 하는 IG-SOFC/GT 시스템의 성능

박성구(Sung Ku Park),김동섭(Tong Seop Kim) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11

An IG-SOFC/GT (Integrated Gasification Solid Oxide Fuel Cell/Gas Turbine) power generation system based on IGCC (Integrated Gasification Combined Cycle) is devised and its performance is analyzed and compared with IGCC system performance. First, the modeling of the IGCC system combining a gasifier block and G-class gas turbine based power block is performed on the basis of an open literature. Then, IG-SOFC/GT system is designed through the integration of a SOFC and the IGCC system. Three system configurations, differing in SOFC inlet temperature management and disposal of notrogen separated from the air separation unit, are compared. General conclusion is that the IG-SOFC/GT system can produce much larger power with a higher efficiency than IGCC system.