• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.6
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• pp.74-85
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• 2022

Since the late 1990s, the demand for developing green or reduced-toxic storable propellants has been rising to replace the existing toxic propellants. Most of the research activities are focusing on development of new hypergolic fuels and either white fuming nitric acid or hydrogen peroxide is utilized as an oxidizer. The newly-developed hypergolic fuels are classified as three types, catalytic fuel, reactive fuel, and ionic fuel. In the present study, recent R&D trend of ionic liquid propellants is described and the main results in the previous studies are analyzed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.269-272
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• 2009

Catalytic decomposition of nitrous oxide was investigated experimentally. Two noble metal catalyst (Pt, Ir) were chosen to decompose nitrous oxide. Each catalyst was tested with different chamber pressure and preheating temperature. Ir decomposed $N_2O$ at lower temperature ($230^{\circ}C$) and suitable for $N_2O$ decomposition. In addition, the minimum required preheating temperature decreased as the chamber pressure increased. However, deactivation of Ir catalyst was observed during the experiments.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.100-103
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• 2012

The blending method that is an addition of small quantity of fuel was used to increase the performance of green propellant thruster. 90 wt.% hydrogen peroxide as a green propellant was selected, and ethanol was used as a blended fuel. The o/f ratio was chosen as 50 which has higher theoretical performance than 98 wt.% hydrogen peroxide. The chamber temperature of blended hydrogen peroxide was higher than adiabatic chamber temperature of hydrogen peroxide. Therefore, performance can be improved by ethanol blending. Several catalyst and its support were compared to find appropriate catalyst for decomposition and combustion of ethanol blended hydrogen peroxide. As a experimental results, Pt was suitable, but $MnO_2$ had a chamber instability when it was reused. The ${\alpha}-Al_2O_3$ which is high heat-resistant support showed very unstable performance in both Pt and $MnO_2$ catalyst since it has low decomposition performance.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.8
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• pp.695-701
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• 2016

Spacecraft propulsion system is a kind of rocket engine that has been developed from the end of 1950s for attitude control and orbit maintenance of satellite. Since the spacecraft propulsion system has to be used for a relatively long time, therefore, stability of propellant and life of thruster could be very important factor for propulsion system design. Recently, green propellant propulsion and all electrical propulsion system have became very important issue, and we also need a development according to well organized plan. In this paper, we will introduce the development status, key technologies and development prospect of spacecraft propulsion system.

• THE HEALTH and ORGANIC FARMING
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• no.185
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• pp.1-24
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• 2002

한국유기농업대회 성황리 개최/제24회한국유기농업대회 대회사/'남성증명서'가 필수 혼수품이 되다니./제24회한국유기농업대회 이모저모/유전자 변형작물 유해 논란속 확산 가속/"쌀소득보전기금" 제정추진/유럽의 어메니티 정책동향/환경개선으로 병해충을 막아보자/친환경농업 양파.마늘 재배기술/12월중 농사정보/당신도 무병장수를 꿈꾸는가?/딸기의주요병해와 친환경적 방제기술/쌀도 브랜드시대/콩 가공식품 인기절정/엽채류 균핵병 방제/유기농업경영의 삼장 통합구상

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.130-133
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• 2009

The sequence of the propellant supply is very important for the reliable and safe operation of a LRE combustion test. So combustion performance tests were performed to find an optimum test sequence by changing supply time of propellants and purge gas in the moment of ignition and extinction. The liquid rocket engine consisted of a catalytic ignitor and six swirl-coaxial injectors which used hydrogen peroxide and kerosene. Conclusively, an optimum sequence was found for stable combustion in the moment of ignition and extinction.

• Clean Technology
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• v.24 no.4
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• pp.371-379
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• 2018

The objective of this study is to develop a platinum/hexaaluminate pellet catalyst for the decomposition of eco-friendly liquid propellant. Pellet catalysts using hexaaluminate prepared by ultrasonic spray pyrolysis as a support and platinum as an active metal were prepared by two methods. In the case of the pellet catalyst formed by loading the platinum precursor onto the hexaaluminate powder and then adding the binder (M1 method catalyst), the mesopores were well developed in the catalyst after calcination at $550^{\circ}C$. However, when this catalyst was calcined at $1,200^{\circ}C$, the mesopores almost collapsed and only a few macropores existed. On the other hand, in the case of a catalyst in which platinum was supported on pellets after the pellet was produced by extrusion of hexaaluminate (M2 method catalyst), the surface area and the mesopores were well maintained even after calcination at $1,200^{\circ}C$. Also, the catalyst prepared by the M2 method showed better heat resistance in terms of platinum dispersion. The effects of preparation method and calcination temperature of Pt/hexaaluminate pellet catalysts on the decomposition of liquid propellant composed mainly of ammonium dinitramide (ADN) or hydroxyl ammonium nitrate (HAN) were investigated. It was confirmed that the decomposition onset temperature during the decomposition of ADN- or HAN- based liquid propellant could be reduced significantly by using Pt/hexaaluminate pellet catalysts. Especially, in the case of the catalyst prepared by the M2 method, the decomposition onset temperature did not show a large change even when the calcination temperature was raised at $1,200^{\circ}C$. Therefore, it was confirmed that Pt/ hexaaluminate pellet catalyst prepared by M2 method has heat resistance and potential as a catalyst for the decomposition of the eco-friendly liquid propellants.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.6
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• pp.97-104
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• 2013

N-Guanylurea dinitramide (GUDN) is an energetic material with low sensitivities and good performance for use as propellants or insensitive munitions explosives. The efficient synthesis and characterization of high energy density material of GUDN is reported. GUDN was characterized spectroscopically as well as elemental analysis. In addition, the heats of formation were calculated with the Gaussian 09 suite of programs. For initial safety testing, the impact sensitivity and the friction sensitivity were tested following BAM procedure.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.105-108
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• 2008

Nowadays, as there is so much interest in environment, hydrogen peroxide attracts attention as an eco-propellant. Hydrogen peroxide is widely used for mono-propellant of thruster, and oxidizer of bi-propellant rocket. Especially, it is used as mono-propellant of the thruster for attitude control of satellite and military weapons. So, the need of long time storage of hydrogen peroxide appears and storage test is required. In this paper, necessity of storage test of hydrogen peroxide and some conditions and methods are introduced. In addition, the results of storage tests under some condition are compared and analyzed.

• KOREAN POULTRY JOURNAL
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• v.43 no.11
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• pp.154-157
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• 2011

지난 9월 29일 서초구 소재 서울교육문화회관에서 농장동물 복지정책 토론회를 개최하였다. 이날 농가 및 관련종사자 100여명이 참석하여 앞으로 실시될 농장동물 복지제도에 대한 많은 관심을 보였다. 이날 토론회는 동물복지 축산농장 인증제 추진과 관련한 전문가 주제 발표, 동물복지 축산농장 인증제 추진방안 및 농가 참여 확대 방안, 동물복지형 축산물 표시제 도입 및 유통 판매처 확보 방안, 소비자 인지도 제고 등 동물복지형 축산물 소비기반 마련 방안, 기타 국내 동물복지제도 정착 및 발전을 위한 토론으로 구성되어 진행되었으며 친환경 농장 경영과 동물복지(전남대학교 조광호 교수), 동물복지 축산농장 인증제 운영 방안(농림수산검역검사본부 동물보호과 한종현 과장), 동물복지 인증과 해외사례(국립축산과학원 축산환경과 유용희 과장)에 대한 발표가 있었으며 건국대학교 이상락 교수가 좌장을 맡은 가운데 본회 안영기 부회장, 동물자유연대 조희경 대표, 전남대학교 조광호 교수, 농림수산식품부 안유영 사무관, 농림수산검역검사본부 한종현 과장, 국립축산과원 유용희 과장, 대한양돈협회 이병석 차장이 토론자로 나섰다. 본고는 이날 발표내용 및 토론내용을 요약, 정리 하였다.