• Title/Summary/Keyword: Secondary formation

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Simulation of Secondary Aerosol Formation by Coagulation Process (응집에 의한 이차 에어로졸 생성 모사)

  • 양소희;김영제;김순태;홍민선
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2000.11a
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    • pp.429-431
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    • 2000
  • 에어로졸의 물리적, 화학적 특성은 주로 입자의 크기 분포와 밀접한 관련이 있다. 따라서 시간에 따른 입자의 크기분포의 변화를 아는 것은 중요한 문제로서, 입자에 작용하는 중력이나, 전기적인 힘, 입자간의 상대속도 등에 의해 입자의 크기분포는 달라질 수가 있다. 이러한 입자간의 상호작용으로 인해 서로 충돌하여 합쳐지는 것으로 이를 응집(Coagulation)이라 한다. (M.M.R. Williams, 1988) (중략)

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Indoor Smog Chamber Study III: Effect of Initial Particle Size Distribution on the Formation and Growth of Secondary Aerosols (실내 스모그 챔버 연구 III: 초기 대기 에어로졸의 입경분포가 2차 에어로졸 생성 및 성장에 미치는 영향)

  • 박주연;배귀남;김민철;김용표;문길주
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2002.11a
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    • pp.391-392
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    • 2002
  • 대기 중에는 오염원으로부터 직접 배출된 1차 에어로졸과 광화학 반응 등에 의해 가스가 입자로 변환되어 생긴 2차 에어로졸이 존재한다. 2차 에어로졸의 생성과정을 규명하기 위하여 스모그 챔버 연구가 많이 수행되고 있다. 본 연구팀에서도 대기를 실내 스모그 챔버에 도입하여 광화학 반응에 의한 2차 에어로졸의 생성 및 성장과정을 규명하는 실험을 수행하고 있다 (박주연 등, 2002). (중략)

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A theoretical approach to the preferred orientation formation of MgO protection layer using adatom diffusion

  • Yu, Hak-Ki;Lee, Jong-Lam
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.713-715
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    • 2009
  • Preferred orientation of MgO protection layer is controlled via adjusting diffusion of adatom between (111) plane with highest neighbor atoms and (200) plane with lowest neighbor atoms. The diffusion of adatom could be modulated by the factors such as substrate temperature, deposition rate, and extra energy applied on adatom like ion beam energy.

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Surgical Treatment of Subglottic Stenosis -2 Cases- (성문하 기관 협착증의 수술 치험 2예)

  • 김종만
    • Journal of Chest Surgery
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    • v.23 no.3
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    • pp.577-583
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    • 1990
  • Subglottic stenosis is a disorder characterized by narrowing of the airway below the glottis. In children, the stenosis is usually due to scar formation secondary to prolonged airway intubation, rather than to external trauma. The location and extent of the stenosis are highly variable, consequently, corrective measures need to be selected to suit the individual problem. Conservative treatment is adequate for lesser degrees of stenosis but those with more severe scarring require external laryngeal surgery. We managed 2 children with subglottic stenosis due to prolonged intubation after open heart surgery who needed a resectional surgery of the stenotic upper airway. The preoperative evaluation and surgical technique for subglottic stenosis were reviewed.

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A Study on the Placeness Formation of Elementary and Secondary School Students in School Libraries (학교도서관에 대한 초·중등 학생의 장소성 형성구조에 관한 연구)

  • Lee, Byeong-Kee
    • Journal of Korean Library and Information Science Society
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    • v.48 no.2
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    • pp.73-97
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    • 2017
  • School Library is both a space and a place. The difference between space and place is the same as in the difference between house and home. Space may be described in terms of physical shape. Place is concept that formulated by personal experience. The social and cognitive developmental stages of elementary, middle and high school students are different, so the placeness or sense of place may be different. The purpose of this study is to figure out the differences in elementary and secondary school student's formative factors of placeness and examine the process that those factors are connected to the results of the user behavioral intentions through the medium of place attachment, place value perception. The data are collected from 590 students and analyzed by SPSS 19 and AMOS 19. The results of this study are as follows. The physical, active behavioral and psychological factors affect on placeness formation of elementary and secondary school students in school libraries. Elementary school students are significantly affected more by physical factors, active behavioral factors than middle and high school students. This study confirmed the process that those factors are connected to the results of the user behavior through the medium of place attachment, place value perception.

Formation Mechanism of Ultrafine $TiO_2$ Powders from Aqueous $TiOCl_2$ Solution by Homogeneous Precipitation Process at Low Temperature (저온 균일침전법으로 $TiOCl_2$ 수용액에서 얻은 $TiO_2$ 초미분체의 형성기구)

  • 김선재;이희균;박순동;전치중;이창규;김흥회;이은구
    • Journal of the Korean Ceramic Society
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    • v.37 no.5
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    • pp.473-478
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    • 2000
  • The TiO2 powder with the values of the large specific surface area more than 150$m^2$/g has been prepared with the homogeneous precipitation process below 5$0^{\circ}C$ and its formation mechanism was investigated using the SEM, TEM and Raman Spectroscopy. With the spontaneous hydrolysis of aqueous TiOCl2 solutions, all the precipitates were fully and homogeneously crystallized with the rutile TiO2 phase simply by heating, which as transformed to the anatase TiO2 phase as increasing the addition of SO42- ions to the aqueous TiOCl2 solution. The precipitates were formed with spherical secondary particles which consisted of acicular, spherical and mixed primary particles corresponding to the rutile, anatase and mixed phases, respectively. It can be thought that the formation and phase determination of crystalline TiO2 powders even at ambient temperature would be related with the existence of the capillary force. This force might be varied depending on the shape change of the primary particles.

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Effect of lysozyme and glycine on the Mageoly brewing process (Lysozyme 및 glycine의 첨가가 막걸리의 품질에 미치는 영향)

  • Lee, Sung-Ki;Kim, In-Ho;Min, Byong-Yong
    • Applied Biological Chemistry
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    • v.33 no.3
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    • pp.252-256
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    • 1990
  • Characteristics of brewing product, Mageoly mashes diluted by the same ratio of water was investigated for alcohol formation, pH change, acid formation nucleotide content and sensory evaluation stored at $3^{\circ}C\;or\;30^{\circ}C$ during 7 days. Each sample was mixed with lysozyme 270ppm and glycine 0.27%, or lysozyme 450ppm and glycine 0.45% on the secondary brewing process in Mageoly brewing. The brewing was not affected by addition of lysozyme and glycine mixture. When the lysozyme-glycine mixture was added during brewing, that resulted in a decrease in pH, a suppression of acid formation and an increase in IMP and inosine content Therefore ere was significantly improved in taste and palatability.

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Ultrastructural Studies on Oocyte Development and Vitellogenesis During Oogenesis in Female Boleophthalmus pectinirostris

  • Chung, Ee-Yung;Choi, Ki-Ho;Jun, Je-Cheon;Choi, Moon-Sul;Lee, Ki-Young
    • Animal cells and systems
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    • v.13 no.1
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    • pp.49-57
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    • 2009
  • For the study of the reproductive mechanism associated with the process of vitellogenesis, oocyte development and vitellogenesis during oogenesis in female Boleophthalmus pectinirostris were investigated by electron microscopic observations. The ovary consists of a pair of saccular structures with many ovarian lobules. In the early vitellogenic oocyte, the Golgi complex plays an important role leading to the formation of yolk vesicles containing carbohydrate yolks. At this time many pinocytotic vesicles containing yolk precursors are observed in the cytoplasm near the region of initial formation of the zona radiata. In the late vitellogenic oocytes, the multivesicular bodies, which are formed by modified mitochondria, are involved in the formation of the primary yolk granules. Precursors of yolk granules and multivesicular bodies develop to primary yolk globules with participation of pinocytotic vesicles. After primary yolk globules mix with each other, they develop into secondary and tertiary yolk globules. Based on these findings, vitellogenesis of B. pectinirostris occurs by way of the processes of endogenous autosynthesis and exogenous heterosynthesis. The process of autosynthesis involves the combined activity of the Golgi complex, mitochondria, and multivesicular bodies. However, the process of heterosynthesis involves pinocytotic incorporation of extraovarian precursors into the zona radiata of vitellogenic oocytes by way of the thecal cell layers and granulosa cells.

THE MULTIPLE PROTO STELLAR SYSTEM L1551 IRS5 AT 5 AU RESOLUTION

  • LIM JEREMY;TAKAKUWA SHIGEHISA
    • Journal of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.237-240
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    • 2005
  • We present images of L1551 IRS5 at angular resolutions as high as ${\~}$30 mas, corresponding to a spatial resolution of ${\~}$5 AU, made at 7 mm with the VLA. Previously known to be a binary protostellar system, we show that L1551 IRS5 is likely a triple protostellar system. The primary and secondary components have a projected separation of ${\~}$46 AU, whereas the tertiary component has a projected separation of ${\~}$11 AU from the primary component. The circumstellar dust disks of the primary and secondary components have dimensions of ${\~}$15 AU, whereas that of the tertiary component has a dimension of ${\~}$10 AU. Their major axes are closely, but not perfectly, aligned with each other, as well as the major axis of the surrounding flattened, rotating, and contracting molecular condensation (pseudodisk). Furthermore, the orbital motion of the primary and secondary components is in the same direction as the rotational motion of this pseudodisk. We suggest that all three protostellar components formed as a result of the fragmentation of the central region of the molecular pseudo disk. The primary and secondary components, but apparently not the tertiary component, each exhibits a bipolar ionized jet that is centered on and which emergers perpendicular to its associated dust disk. Neither jets are resolved along their base, implying that they are driven within a radial distance of ${\~}$2.5 AU from their central protostars. Finally, we show evidence for what may be dusty matter streams feeding the two main protostellar components.