• Title/Summary/Keyword: 미립형태

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Spore morphology of Korean Thelypteridaceae (한국산 처녀고사리과 식물의 포자형태)

  • Moon, Su Mi;Sun, Byung-Yun
    • Korean Journal of Plant Taxonomy
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    • v.38 no.4
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    • pp.459-476
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    • 2008
  • Taxonomic characteristics of spores of 17 species belonging to 6 genera of the Korean Thelypteridaceae are examined. Description of each species and key to the species are provided. Spores of Korean Thelypteridaceae are monad and monolete with bilateral symmetry. Perispore, the sporoderm of spore, was found in all the species examined. The perispores and exospores of Thelypteris japonica var. japonica, T. japonica var. glabrata and Pseudocyclosorus subochthodes are much similar to each other, but the rest of taxa examined shows diverse patterns of the surface ornamentation of perispores and exopores enough to distinguish genera and sometimes to distinguish species in some genera. Previous study reported that perispore is not easily distinguished from exospore in Cyclosorus and Leptogramma. However, three species of Cyclosorus examined here show different pattern having scabrate or verrucate exospores and cristate or echinate perispores. Leptogramma pozoi ssp. mollisima also have echinate perispore and fossulate exospore. Macrothelypteris oligophlebia var. elegans and M. viridifrons have scabrate exospore which is contrast to previous report of reticulate exospore. Thelypteris glanduligera, T. angustifrons and T. laxa show same patterns of perispore and exospore with reticulate perispore and fossulate exospore and hence cannot be distinguished by spores only.

Preparation of Thin TiO$_2$ Photocatalytic Filter for Waste Gas Treatment (폐가스 처리를 위한 박막형 TiO$_2$ 광촉매 필터 제조)

  • 조영민;윤정호
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2002.04a
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    • pp.311-312
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    • 2002
  • 환경분야에서 광촉매는 주로 오염물질의 광분해처리에 이용되고 있는데, 기존에 사용되고 있는 광분해 방법은 광촉매 미립자를 수용액에 슬러리 형태로 분산시키거나 fixed bed, fluidized bed에 부착시킨 형태의 반응기들이다. 실험적 수준의 연구로부터 얻어진 여러 연구 결과에 의하면 슬러리 형태의 반응기가 고정화 촉매 반응기보다 효율이 더 높은 것으로 보고되고 있다. 그러나 엔지니어링 관점에서 슬러리형 반응기는 촉매의 재활용과 정화 처리 후 촉매입자를 유체로부터 분리해야하는 결점이 있다. (중략)

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Vaned Wheel Atomization of CWM (Vaned Wheel Atomizer에 의한 CWM 미립화)

  • 김성준;김용선
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.5
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    • pp.974-982
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    • 1992
  • The atomizations of CWM slurry and water are done by a wheel atomizer which is designed and manufactured for this experiment. The variables of the experiment are the angle of vane, aspect ratio, particle loading and the mean size of coal particle distribution. The main purposes of the experiment are to know how the angle of vane and aspect ratio of vane influence the size distribution of CWM droplets. The experimental results say there are no appreciable effects on the mean size of CWM droplets from the change of loading of coal prticles in slurry. The mean size of coal particle in slurry, however, influence quite strongly the mean size of CWM droplets. The mean size of CWM droplets is quite strongly affected by the angle of vane. The size distribution of CWM droplets is controllable by the change of aspect ratio.

Surface Morphology Control of Monodisperse Crosslinked-Polymer Particle (단분산 가교고분자 미립자의 표면 모폴로지 제어 연구)

  • Kim, Dong-Ok;Jin, Jeong-Hee;Oh, Seok-Heon
    • Polymer(Korea)
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    • v.30 no.1
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    • pp.50-55
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    • 2006
  • When the monodisperse polystyrene(PS)/HDDA polymer particles were synthesized via one-step polymerization using polystyrene seed particles by dispersion polymerization, the effects of 1) the molecular weight of seed polymer particles, 2) the ratio of the absorbed HDDA to the seed polymer particles (swelling ratio) and 3) seeded polymerization rate on the surface morphology of PS/HDDA polymer particles were investigated. It was observed that the creation of the crater shaped defect on the surface of PS/HDDA polymer particles was irrespective of the molecular weight of seed polymer ant swelling ratio. But its surface morphology could be controlled by the change of the seeded polymerization rate.

Permeation Behavior of Semiconductor Rinsing Wastewater Containing Si Particles in Ultrafiltration System -I. Permeation Characteristics of Polysulfone Flat Plate Membrane- (Si 입자를 함유한 반도체 세정폐수의 한외여과 특성[I] -Polysulfone 평판막에 의한 투과분리-)

  • 곽순철;이석기;전재홍;남석태;최호상
    • Membrane Journal
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    • v.8 no.2
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    • pp.102-108
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    • 1998
  • Permeation behavior of the semiconductor rinsing wastewater containing Si particles was examined by ultrafiltration using the polysulfone plate membrane. The permeation flux was gradually decreased with time. It was due to the growth of cake deposited on the membrane surface and the pore plugging by Si particles. Permeation flux of cross flow type was 1.4 times higher than that of the dead end flow type. Nitrogen back flushing which is the removing method of membrane fouling was superior to the water sweeping. With nitrogen back flushing, the decrease of permeation flux due to the fouling was recovered about 85 % to the initial flux in the flat plate membrane system. The rejection rate of Si particles was about 90 % and the size of Si particle in the permeate was about 70 nm.

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Petrographical study for the enclaves of the granitic rocks, in the Gyeongsang Basin, Korea (경상분지 화강암류에서 발견되는 엔클레이브(포유암)에 대한 암석기재적 연구)

  • 김종선;김건기;좌용주;이준동
    • The Journal of the Petrological Society of Korea
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    • v.13 no.1
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    • pp.1-15
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    • 2004
  • In this study we propose that the ‘enclaves’ which occur in the granites should be translated into ‘Po-yu-am’in Korean. Also we suggest some criteria to discriminate the mafic microgranular enclaves (MME) of igneous origin from the xenoliths, which possibly come from the plutonic, volcanic and sedimentary country rocks. The color of the MME is gray green∼dark gray and the mineral grains are fine and equigranular. The MME are generally of ellipsoidal shape and can be easily found within the granites. They do not show any evidence of contact metamorphism by granite host. On the other hand. the xenoliths are generally of angular shape and are of the same mineral assemblage and texture as the country rocks around the granites. The distribution of the xenoliths is mostly concentrated along the intruding plane of the granites near the country rocks. The xenoliths were partly metamorphosed by the granite intrusion. The xenoliths from the plutonic rocks are easily distinguished from the MME in terms of their angular shape and coarser grain size, but they do not have any metamorphic mineral assemblage and texture. The xenoliths from the tuffaceous rocks show angular shape and porphyritic and pyroclastic textures. Large size xenoliths from the sedimentary rocks specifically preserve bedding structure which are indicative of the sedimentary strata. However, the sedimentary xenoliths of small size are often difficult to distinguish from the MME. Metamorphic minerals and texture are a useful key to discriminate the small-sized sedimentary xenoliths from the MME. In summary the xenoliths in the granites can be megascopic ally distinguished from the MME by comparing their color, shape, grain size and remnant original structure like bedding. Additionally the metamorphic mineral assemblage and texture are microscopic discriminators between the xenoliths and the MME in the granites.

Preparation and Characterization of Zaltoprofen-Loaded Polyoxalate Microspheres for Control Release (방출제어를 위한 잘토프로펜이 함유된 폴리옥살레이트 미립구의 제조와 특성)

  • Kim, Kyoung Hee;Lee, Cheon Jung;Jo, Sun A;Lee, Jung Hwan;Jang, Ji Eun;Lee, Dongwon;Kwon, Soon Yong;Chung, Jin Wha;Khang, Gilson
    • Polymer(Korea)
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    • v.37 no.6
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    • pp.702-710
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    • 2013
  • Zaltoprofen loaded polyoxalate (POX) microspheres were prepared by an emulsion solvent-evaporation/extraction method like oil-in-water (O/W) for sustained release of zaltoprofen. The influence of several preparation parameters such as fabrication temperature, stirring speed, intensity of the sonication, initial drug ratio, molecular weight ($M_w$) of POX, concentration of POX and concentration of emulsifier has been investigated on the zaltoprofen release profiles. Physicochemical properties and morphology of zaltoprofen loaded POX microspheres were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimeter (DSC) and Fourier transform infrared (FTIR). Through the analyzed results, it was demonstrated that the characteristics of the microspheres greatly affected by the prepared condition. The releases behavior of zaltoprofen was investigated for 10 days in vitro. It was confirmed that the release behavior of zaltoprofen can be controlled by the manufacturing factor of solvent-evaporation/extraction method.

A Palynological Study of the Korean Oldenlandia L. (Rubiaceae) (한국산 백운풀속(꼭두서니과)의 화분학적 연구)

  • Nam, Bo Mi;Chung, Gyu Young
    • Korean Journal of Plant Taxonomy
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    • v.41 no.2
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    • pp.108-112
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    • 2011
  • The pollen of 5 taxa on Korean Oldenlandia L. was investigated by LM and SEM. The pollen grains were monads, $20.7-36.0{\mu}$m in polar length, with an equatorial diameter of $21.0-38.4{\mu}m$. The pollen shapes were oblate-spheroidal or spherical (P/E ratio 0.93-1.00). The apertures numbered 3-7 in number, colporate in shape, with a colpus length of $4.2-20.4{\mu}m$ and a colpus width of $2.6-3.4{\mu}m$. The sexine was $0.9-2.4{\mu}m$ in terms of its thickness, the surface pattern was reticulate, scabrate or neither. Based on these results, the size of the pollen grain, the number of apertures, and the surface pattern of the sexine were all useful for an interspecific classification. The genus Neanotis, established via the pollen characteristics, was thought to be reviewed in its entity regarding the continuous variation of generic characteristics.