• Title/Summary/Keyword: 화랑21

Search Result 5,961, Processing Time 0.032 seconds

Chlorodifluoromethane (CHClF2) Thermal Decomposition by DC Nitrogen Plasma (질소 플라즈마 공정을 이용한 염화이불화메탄(CHClF2) 열분해)

  • Ko, Eun Ha;Yoo, Hyeonseok;Jung, Yong-An;Park, Dong-Wha;Kim, Dong-Wook;Choi, Jinsub
    • Applied Chemistry for Engineering
    • /
    • v.28 no.2
    • /
    • pp.171-176
    • /
    • 2017
  • The nitrogen plasma thermal decomposition and recovery processes for $CHClF_2$ (Chlorodifluoromethane) refringent were investigated. The steam generator was employed to provide superheated steam reactor, supporting the decomposition reaction of refringent. Even though over 94% of R-22 was decomposed on the condition of 60 A and 9.0 kW, a higher power and specific energy density were required to achieve the complete combustion of carbon materials. In the operating condition of 60 A and 12.6 kW, $O_2$/R-22 ratio in reactants gases are a key factor to obtain much higher decomposition ratio during process. It should be noticed that injecting the mixture of $O_2$ and air was much more effective than injecting the air consisting equivalent $O_2$ amount.

Aerobic Composting Process of Garbage using Thermoacidophilic Bacillus sp. SJ-15. (고온.내산성 Bacillus sp. SJ-15를 이용한 음식물 쓰레기의 호기적 퇴비화)

  • Kim, Choon-Hee;Nam, Soo-Wan;Choi, Woo-Bong;Lee, Jong-Hwan;Kang, Byoung-Won;Kim, Hweh-Su;Jeon, Sung-Jong
    • Journal of Life Science
    • /
    • v.17 no.5 s.85
    • /
    • pp.735-739
    • /
    • 2007
  • A thermoacidophilic bacterium was isolated from the compost and designated as Bacillus sp. SJ-15 by physiological and biochemical characteristics. The optimum temperature and pH for growth were at $55^{\circ}C$ and pH 5.0, respectively. The strain SJ-15 was adapted in process of accelerated high-temperature composting of garbage. The highest viable cell count of composting process reached to $9.2{\times}10^9/ml$ in 16 hours. After running times of 100 days, the composting process showed a reduction rate of approximately 88%, and the concentrations of components were sufficiently high or low to satisfied the standard of organic compost except for salinity.

The method for applying International Standards to Korean Industrial Standards in Construction fields - The standards of sampling and testing the fresh concrete - (건설분야에서 국내표준과 국제표준의 부합화 방안 - 콘크리트 시료채취와 시험방법에 대한 규격을 중심으로 -)

  • Lee Teck-wn;Kuk Chan-ho;Han Choong-hee
    • Korean Journal of Construction Engineering and Management
    • /
    • v.2 no.4 s.8
    • /
    • pp.107-116
    • /
    • 2001
  • As the international trade has been increased, unified worldwide standards are getting more important and necessary. At the TBT(Agreement on Technical Barrier to Trade) of WTO(World Trade Organization) and the CTI meeting of APEC(Asia-Pacific Economic Cooperation), they made an agreement with applying International Standards to National Standards gradually. In addition, ISO (International Organization for Standardization) established the ISO/IEC Guide 21, a guideline for applying International Standards to National Standards. In these environment, Korean Industrial Standards has to be prepared for it. This paper introduce the comparison between Korean Industrial Standards and ISO Standards about the standards of sampling and testing the fresh concrete, based on ISO/IEC Guide 21 by ISO and the Applying guideline by Korean Agency for Technology and Standards, and then discuss the problem about applying them. The overall objective is to establish the applying guideline on construction fields, which is civil and building engineering part(KS F) of Korean Industrial Standards.

  • PDF

Studies on the Synthesis of 1-Hydroxycarbapenems (1-히드록시카르바페넴의 합성에 관한 연구)

  • You, Jong Hyeon;Park, Jeong Ho;Goo, Yang Mo;Lee, Yun Yeong
    • Journal of the Korean Chemical Society
    • /
    • v.42 no.1
    • /
    • pp.69-77
    • /
    • 1998
  • (3S,4S)-1-(t-Butoxycarbonylmethyl)-3-[(S)-1-(t-butyldimethylsilyloxy)ethyl]-4-(2-diazo-2-ethoxycarbonyl-1-oxoethyl)-2-azetidinone (14) was prepared from 4-styryl-2-azetidinone 7b via a sequence of reactions involving N-alkylation with bromoacetate, ozonolysis, oxidation, condensation with magnesium ethyl malonate, and diazo transfer reaction. (3S,4S)-3-[(S)-1-(t-Butyldimethylsilyloxy)ethyl]-4-(3-diazo-3-ethoxycarbonyl1-hydroxypropyl)-2-azetidinone (21) was also prepared from 4-formyl-2-azetidinone 5b via a sequence of reactions involving Wittig reaction, 1,3-dipolar cycloaddition with ethoxycarbonylformonitrile oxide, catalytic hydrogenation, and diazotization. However, the final cyclization of 14 or 21 to 1-hydroxycarbapenem or 1-hydroxycarbapenam by treating with $Rh_2(OAc)_4$ was unsuccessful.

  • PDF

A case of adrenocortical adenoma following long-term treatment in a patient with congenital adrenal hyperplasia (장기간 치료받은 부신 피질 과형성증 환아에서 발생한 부신 피질 종양 1례)

  • Lho, Seung Rim;Park, So Hyun;Jung, Min Ho;Lee, Byung Churl
    • Clinical and Experimental Pediatrics
    • /
    • v.50 no.3
    • /
    • pp.302-305
    • /
    • 2007
  • As a result of the widespread use and enhanced quality of high-resolution radiological techniques, a recent report has revealed a relatively high prevalence of small adrenal tumors in patients with untreated congenital adrenal hyperplasia due to 21-hydroxylase deficiency. However, there are scarcely any pediatric cases of adrenocortical tumor following long-term treatment in patients suffering with congenital adrenal hyperplasia. We report here on a pediatric female case of adrenocortical adenoma despite adequate long-term treatment for the salt-losing type of congenital adrenal hyperplasia.

클라우드 컴퓨팅 환경 기반의 가상화 기술 및 네트워크 분석 기법 관련 동향

  • Suh, Jeong-Jun;Shin, Youngsang;Jeong, Hyun-Cheol
    • Review of KIISC
    • /
    • v.22 no.7
    • /
    • pp.21-26
    • /
    • 2012
  • 가상화 기술은 클라우드 컴퓨팅 환경에 있어서 주요 기술 가운데 하나이며, 최근 가상화 관련 연구가 활발히 이루어지고 있다. 특히 클라우드 컴퓨팅 환경 기반의 가상화 구현에 있어서 중요한 기술로는 하이퍼바이저가 있다. 또한 클라우드에서의 주요 이슈 중에 하나인 정보의 보호와 관련하여, 악의적인 공격을 탐지하고 대처할 수 있는 가상화 시스템의 분석에 대해 연구되고 있다. 본 논문에서는 클라우드 컴퓨팅 환경에서의 주요 기술과 대표적인 가상화 플랫폼에 대해 알아보며, 가상화 시스템에서의 네트워크 분석 기법과 관련된 동향을 통해 클라우드 컴퓨팅 환경에 있어 정보의 보호 측면에 대해 전반적으로 논의해 보도록 한다.