• Title/Summary/Keyword: 방출기

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Preparation and Characterization of BICND-loaded Multi-Layer PLGA Wafer Containing Glycolide Monomer (글리콜라이드 단량체를 함유한 BICNU 함유 다중층 PLGA웨이퍼의 제조 및 특성결정)

  • 채강수;이진수;정제교;조선행;이해방;강길선
    • Polymer(Korea)
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    • v.28 no.4
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    • pp.335-343
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    • 2004
  • Carmustine (l,3-bis(2-chloroethyI)-1-nitrosourea, BICNU) used as antineoplastic drug for the treatment of brain tumor is not appropriate for the long term delivery, because it has short biological half life. Therefore, poly(D,L-lactide-co-glycolide) (PLGA) is useful as drug carrier for the long term delivery due to bulk erosion property. Glycolide monomer is applied to release of BICNU owing to non-toxic and monomeric components after biodegradation of PLGA. In this study, BICNU-loaded PLGA wafers with or without glycolide monomer were fabricated by conventional direct compression method for the sustained release of BICNU. These wafers were observed for their release profiles of BICNU and degradation rates by SEM, NMR, and GPC. Furthermore, we make multi-layer wafers and compare them with release profiles of conventional wafer. From these results, drug release of BICNU-loaded PLGA wafers was increased with increasing the glycolid monomer contents. We confirmed that glycolide monomer and BICNU contents in barrier-layer influenced the drug release profiles and degradation rate.

Optimized Flooding Analysis Method for Compartment for Nuclear Power Plant (원전 격실에 대한 최적 침수분석 방법)

  • Song, Dong-Soo;Kim, Sang-Yeol
    • Journal of Energy Engineering
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    • v.21 no.1
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    • pp.75-80
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    • 2012
  • In this paper a realistic bounding method for flooding analysis following rupture of large size of thanks and piping is defined. Mass and energy release during main feedwater line break accident is analyzed with RETRAN code. It is modeled that the main feed water control valve is closed in 5.0 seconds after reactor trip. In result of the analysis, largest mass and energy is discharged at 70% reactor power. The flood sources for main feedwater room are calculated when piping failure occurs in the high energy line and medium energy line. Based on the result of flood level (1.43m), it is investigated that all of the safety-related environmental qualification equipments are well located above the flood level.

A study on ultrasound analysis of the transformer strange signal (변압기 이상음의 초음파 분석에 관한 연구)

  • 백화종;지석근
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.11a
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    • pp.835-838
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    • 2002
  • A running high voltage equipments produce ultrasonic wave that has unique sound by the specific characteristics of the electricity. The generation of the ultrasonic wave is made by the electric transform like arcing, corona, and tracking so on. The mechanical losses and fatal human damages are happened by the electric failure of high voltage equipments. To prevent and diagnose the obstacle factors of the high voltage equipments, the measurement of the ultrasonic wave became to be prominent. However standardized data have been a deficient situation by now. This paper measures the ultrasonic wave coming from the real running transformer equipments and transforms it as an audio frequency. Measured data represents as frequency and time domain through the FFT(Fast Fourier Transform) transform. In conclusion, the purpose of this paper is to standardize the analyzed data.

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Optimization of the Coupling and the Reflector Material in the DOI PET Detector Module using the WLS Fiber (파장변이섬유를 사용하는 반응 위치 측정 양전자방출 단층촬영기기 검출기 모듈의 연결물질과 반사체 물질의 최적화)

  • Lee, Seung-Jae
    • Journal of the Korean Society of Radiology
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    • v.13 no.1
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    • pp.15-20
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    • 2019
  • We developed a novel depth-of-interaction positron emission tomography (PET) detector using wavelength shifting (WLS) fibers and optimized it. The optimization module was designed by using two scintillators and three WLS fibers and attaching a sensor to the end of the WLS fiber. Optimum combinations were obtained through the light collection efficiency and the light collection ratio between sensors depending on coupling materials and reflectors of scintillators, WLS fibers and sensors. The highest light collection efficiency and the light collection ratio between sensors were obtained in the combination of the epoxy (coupling materials)-diffuse reflector (scintillators)-specular reflector (WLS fibers).

Sexual Maturation and Gametogenic Cycle of the Hard Shelled Mussel, Mytilus coruscus (Bivalvia: Mytilidae) (홍합, Mytilus coruscus의 성 성숙과 생식주기)

  • 위종환;장영진;이승주;허영백;이정식
    • Journal of Aquaculture
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    • v.16 no.4
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    • pp.245-251
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    • 2003
  • Sexual maturation and gametogenic cycle of the hard shelled mussel, Mytilus coruscus were investigated by means of histological method. Specimens were collected monthly in Hansan Bay of south coast, Korea from January to December 2002. Sex of the clam was dioecious. The gonads are composed of a number of gametogenic follicles. The gonad index (GI) was reached the maximum in February (3.40), and the minimum in August (1.18). The monthly variation of condition index (CI) coincides with gonad index. The main spawning occurs between February and March. The gametogenic cycle of the clam could be divided into six stages: resting (August to November), multiplicative (November to December), growing (December to January), maturation (January to February), partially spent (February to April) and completely spent/degenerative stage (April to July). Sex ratio (♀/♂) was 1:0.96.

생물막 연속회분식 반응기를 이용한 영양염류의 동시제거에 관한 연구

  • 박민정;김동석
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2003.05a
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    • pp.117-121
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    • 2003
  • SBR과 SBBR 모두 대부분의 유기물은 포기기간에 소모되었으며, SBBR의 경우 부족한 유기물 조건에서도 원활한 탈질화 반응이 일어난 것을 볼 때, 유기물 농도가 낮은 우리나라의 하수에 적합한 공정으로 생각된다. 질산화 속도에 있어서는 유기물과 용존산소의 접촉기회에 있어 유리한 조건을 가진 SBR이 더 크게 나타났다. 그러나 탈질화 반응에 있어서는 SBBR이 더 높은 것으로 나타났다. SBR의 경우 높은 $NO_3$의 존재로 인해 1차 비포기 기간중 인의 방출은 거의 발생하지 않았으나, SBBR의 경우 1차 비포기 기간에 인 방출과 1차 포기기간에 인 섭취가 일어났다.

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Dry Nitrogen Venting System for Ultra-high Vacuum (초고진공용 건조질소 통풍장치)

  • 이성수;유선일;정진욱;정석민
    • Journal of the Korean Vacuum Society
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    • v.1 no.3
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    • pp.332-335
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    • 1992
  • 초고진공 시스템에 있어서 시스템을 대기압으로 바람을 넣은 후 정상상태로의 신 속한 원상회복을 위하여 건조질소 통풍(venting) 장치를 고안 제작하였다. 이 장치는 액체 질소 저장통, 증발기 및 여과기로 구성되어 있다. 이 장치에 의한 통풍효과와 다른 방법에 의한 통풍효과를 가스 방출률 측정을 통하여 정성적으로 비교 분석하였을 때, 본 장치가 가 장 낮은 가스 방출률과 가장 빠른 진공회복을 보여주었다.

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The Study on Characteristics of VOCs and Formaldehyde Emissions Rate from Building Materials (건축자재에서 발생되는 VOCs와 HCHO의 방출특성에 관한 연구)

  • Jang, Mi;Kim, Sin-Do;Yoon, Joong-Sub
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.11a
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    • pp.261-262
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    • 2003
  • 현대인들은 하루 중 80∼90% 이상의 많은 시간을 실내에서 생활하고 있어 실내에서의 발생되는 오염물질에 대한 특성파악은 무엇보다도 중요하다. 실내오염물질의 종류와 발생원은 매우 다양하며, 최근에는 산업발달과 더불어 수 많은 종류의 새로운 복합화합물질들이 발생되고 있다. 신축건물에 사용되는 건축자재는 휘발성유기화합물(VOCs)과 포름알데히드(HCHO)등의 다양한 유해화학물질들을 방출하고 실내공기질을 악화시키는 것으로 조사되고 있다. (중략)

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A Study on Volatile Organic Compounds(VOCs) and Formaldehyde(HCHO) Emission Characteristics from Furniture (가구에서 발생되는 VOCs와 Formaldehyde의 방출특성에 관한 연구)

  • 김신도;서병량;윤중섭
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2001.11a
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    • pp.163-164
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    • 2001
  • 휘발성유기화합물(VOCs)과 포름알데히드(HCHO)의 발생원은 매우 다양할 뿐만아니라 주변환경과 인체에 미치는 영향이 매우 크다. VOCs와 포름알데히드의 발생원으로는 크게 인위적인 발생원, 자연적인 발생원, 실내에서의 발생원으로 구분할 수 있다. 현대인들의 하루생활 중 80%이상이 실내에서 이루어지고 있어 실내에서의 발생되는 오염물질에 대한 특성파악과 적절한 제어방안이 요구된다. VOCs와 포름알데히드의 발생원중에서 실내에서의 발생원으로는 여러 가지가 있으나, 신축건물과 리모델링에 사용되는 건축자재에서의 방출은 매우 크다고 할 수 있다. (중략)

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