• 제목/요약/키워드: Peroxide

검색결과 3,765건 처리시간 0.036초

과산화수소 단일 추진제 PDE의 성능 특성에 관한 수치적 연구 (Performance Characteristics of Hydrogen Peroxide Mono Propellant PDE (Pulse Detonation Engine))

  • 조흥식;정인석;최정열
    • 한국연소학회:학술대회논문집
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    • 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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    • pp.153-157
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    • 2003
  • Supersonic and hypersonic aircrafts must pass wide range of speed to reach high speed region. But for existing engines the most efficient operating speed ranges are decided according to their flying speed, so an engine which mixes several engines like TRJ (Turbo Ramjet) and ARJ (Air Turbo Ramjet) has been planed. This mixed type engine has inefficiency that more than two engines must be installed simultaneously, but the pulse detonation engine (PDE) that uses detonation wave has a strong point that it can operate in all speed range with single engine. This paper deals with the simulation of the pulse detonation engine which uses hydrogen peroxide $(H_2O_2)$ mono propellant. Hydrogen peroxide is low-cost propellant, and it is reacted without oxidizer. Comparison between $H_2-O_2$ mixture with $H_2O_2$ mono propellant about thrust, pressure, temperature and velocity shows that $H_2O_2$ is a very useful propellant.

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대기중 total peroxide 측정 (measurement of total peroxids in the atmosphere)

  • 김규수;권범근;홍상범;정용국;이재훈
    • 한국대기환경학회:학술대회논문집
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    • 한국대기환경학회 2001년도 추계학술대회 논문집
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    • pp.321-322
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    • 2001
  • 대기중 과산화수소($H_2O$$_2$)는 기상과 액상에서 peroxy radicals 간의 결합 (HO$_2$ㆍ+ HO$_2$$\longrightarrow$$H_2O$$_2$+O$_2$)에 의해 생성된다. 만약 수소 원자 하나가 organic group으로 치환되면 organic peroxides가 생성된다(Calvert et al., 1985). 이러한 과산화수소($H_2O$$_2$)와 methylhydroperoxide(MHP, $CH_3$COOH), hydroxymethylhydroperocide(HMHP, HOC$H_2O$OH)등의 organic peroxides는 대기 중에서 주요 산화제로 작용한다. 이들 peroxide 물질들은 pH 5 이하의 aqueous phase (cloud, fog and rain water)에서 sulphuric acid (HSO$_4$$^{2-}$ ) 형성에 중요한 역할을 한다(Calvert et al., 1985). (중략)

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펜톤 산화공법을 통해 디젤로 오염된 토양 처리 시에 과산화수소와 디젤의 주입비 영향에 관한 연구

  • 임명희;손영규;윤준기;김지형
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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    • pp.37-40
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    • 2006
  • The batch tests were performed to determine the ratio of hydrogen peroxide on diesel contaminated soil. The objective of test was to determine and optimize the hydrogen peroxide requirements for the remediation of a soil contaminated with diesel fuel. The batch test were done on 5g diesel contaminated soil containing hydrogen peroxide (34.5%). Initial diesel concentration were 2,000mg/kg, 5,000mg/kg, and 10,000mg/kg. The $Diesel(g):H_2O_2(g)$ ratio varied 1:1, 1:10, 1:50, 1:100, with contact reaction time 120 min. Results the batch test, effective ratio of $Diesel(g):H_2O_2(g)$ is 1:100.

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근관세척(根管洗滌)에 관(關)한 주사전자현미경적(走査電子顯微鏡的) 연구(硏究) (A SCANNING ELECTRON MICROSCOPIC STUDY OF THE EFFICACY OF ROOT CANAL IRRIGATION)

  • 이명종
    • Restorative Dentistry and Endodontics
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    • 제8권1호
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    • pp.147-153
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    • 1982
  • The purpose of this study is to observe the effect of cleansing action of irrigation solutions which are 3% hydrogen peroxide, 5% sodium hypochlorite and 15% EDTA solution on the root canal wall. After the root canal wall is enlarged with K-file in distilled water, the canal wall which is irrigated with each irrigant for 2 minutes, is compared with the. control group without using any irrigants. Each sample is dehydrated, and coated with 200-250${\AA}$ of gold, and observations are made with the use of scanning electron microscope. The results are as follows: 1. The canal walls irrigated with 3% hydrogen peroxide, 5% sodium hypochlorite and 15% EDTA solution are cleaner than the walls without using irrigants. 2. There are no significant difference of cleansing effect among 3% hydrogen peroxide, 5% sodium hypochlorite and 15% EDTA. 3. After using 3% hydrogen peroxide and 5% sodium hypochlorite solution, large debris are removed on root canal walls, but micro debris remain on the canal walls. 4. The root canal walls irrigated with 15% EDTA solution are decalcifed slightly and show clean surfaces.

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바나듐(IV) 촉매존재하에서 과산화수소에 의한 디메틸술폭시드의 산화반응 (Vanadium(IV)-Catalyzed Oxidation of Dimethylsulfoxide by Hydrogen Peroxide)

  • 김창수;문상칠;장승현
    • 대한화학회지
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    • 제32권6호
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    • pp.567-574
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    • 1988
  • 바나듐(IV)촉매가 존재하는 물 및 알코올 수용매에서 과산화수소에 의한 디메틸술폭시드의 산화반응은 디메틸술폭시드와 산농도에 각각 일차의존성임을 보여주었다. 이 산화반응의 속도 결정단게는 황이 바나듐(V)-과산화물의 O-O결합에 대하여 친핵적 공격을 함으로서 디메틸술폭시드가 산화되는 과정임을 제시한다.

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분말탈색제와 산화제를 이용한 헤어색상변화 (A Study on Changes of Hair Colors by Means of Powder Decolorant and Oxidizers)

  • 강평미
    • 한국패션뷰티학회지
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    • 제2권3호
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    • pp.68-73
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    • 2004
  • The purpose of this study was to review the changes of hair colors by means of powder decolorant and oxidizers. For this purpose, a questionnaire survey on uses of powder decolorant and oxidizers was conducted, and the collected data thereby were analyzed. This study was concluded as follows; First, it was confirmed that when the hydrogen peroxide was used alone, the hair color was not changed however its concentration was high. Second, when powder decolorant and hydrogen peroxide were mixed at the ratio of 1:2, it was found that the higher the concentration of hydrogen peroxide was, hair color was changed more. Third, it was confirmed that the hair color became brighter when hairs were decolored three times serially. Fourth, it was found that hairs became tougher when the concentration of hydrogen peroxide was higher and when hairs were decolored many times serially.

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과산화수소 발생을 위한 전해셀용 양성자 교환 막의 비교 (The comparative study of different membranes for electrolytic cell for the hydrogen peroxide generation)

  • 유선경;김한주;박수길
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 제38회 하계학술대회
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    • pp.1361-1362
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    • 2007
  • There is great interest in the applicability of electrogenerated hydrogen peroxide to a wide variety of industrial processes, usually involving oxidation of organics. Hydrogen peroxide is now employed for the bleaching of mechanical pulp and the bleaching of chemical pulp in the pulp and paper industry, thus displacing the traditional alkaline treatments with chlorine-based chemicals. This psper reperts a comparative study of $H_{2}O_{2}$ electogeneration on gas-diffusion electrode in divided cell with several $Nafion^{(R)}$ protonexchange membranes, Russian cation-exchange membrane MK-40 and SPEEK membrane. The influence of different PEMs on electrochemical cell voltage, current efficiency and energy consumption of hydrogen peroxide electrogeneration has been stadied.

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Assessment on combined repeated dose and reproduction/developmental toxicity of benzoyl peroxide

  • Sanghwan Song;Kim, Su-Hyon;Heekyung Bae;Lee, Moon-Soon;Park, Kwangsik
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2002년도 Molecular and Cellular Response to Toxic Substances
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    • pp.171-171
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    • 2002
  • This study was carried out by an Korean GLP laboratory to assess the combined repeated dose, reproduction and developmental toxicity of benzoyl peroxide for OECD SIDS(Screening Information Data Set) program. Male and female Sprague Dawley rats were exposed to benzoyl peroxide at levels of 0, 250, 500 and 1,000 mg/kg/day for 29 days for male and for 41-51 days for female.(omitted)

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Determination of Trace Anions in Concentrated Hydrogen Peroxide by Direct Injection Ion Chromatography with Conductivity Detection after Pt-Catalyzed On-Line Decomposition

  • 김도희;이보경;이동수
    • Bulletin of the Korean Chemical Society
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    • 제20권6호
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    • pp.696-700
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    • 1999
  • A method has been developed for the determination of trace anion impurities in concentrated hydrogen peroxide. The method involves on-line decomposition of hydrogen peroxide, ion chromatographic separation and subsequent suppressed-type conductivity detection. H2O2 is decomposed in Pt-catalyst filled Gore-Tex membrane tubing and the resulting aqueous solution containing analytes is introduced to the injection valve of an ion chromatograph for periodic determinations. The oxygen gas evolving within the membrane tubing escapes freely through the membrane wall causing no problem in ion chromatographic analysis. Decomposition efficiency is above 99.99% at a flow rate of 0.4mL/min for a 30% hydrogen peroxide concentration. Analytes are quantitatively retained. The analysis results for several brands of commercial hydrogen peroxides are reported.

과산화수소 가스발생기 설계와 터보차저를 이용한 동력 측정 방법 검토 (Hydrogen Peroxide Gas Generator Design and Investigation of Power Measurement Method Utilizing Turbocharger)

  • 박대종;안성용;권세진
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2008년도 제31회 추계학술대회논문집
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    • pp.41-44
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    • 2008
  • 터빈 제너레이터 구동을 위한 과산화수소 촉매분해반응을 이용한 가스발생기를 설계하였다. 90 wt%의 rocket grade 과산화수소 가스발생기는 이산화망간을 촉매로 사용하였으며 온도와 압력조절이 용이하여 다양한 조건으로 터빈을 작동시키는데 적합하여 선정되었다. 가스발생기를 이용한 터빈 제너레이터에 대해 조사를 하고 소형 터빈 제너레이터를 개발하는데 앞서 차량용 터보차저를 이용하는 선행연구를 기획하였다.

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