• Title/Summary/Keyword: Compact Disc

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Reliability and Accuracy of the Deployable Particulate Impact Sampler for Application to Spatial PM2.5 Sampling in Seoul, Korea (서울시 PM2.5 공간 샘플링을 위한 Deployable Particulate Impact Sampler의 성능 검증 연구)

  • Oh, Gyu-Lim;Heo, Jong-Bae;Yi, Seung-Muk;Kim, Sun-Young
    • Journal of Korean Society for Atmospheric Environment
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    • v.33 no.3
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    • pp.277-288
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    • 2017
  • Previous studies of health effects of $PM_{2.5}$ performed spatial monitoring campaigns to assess spatial variability of $PM_{2.5}$ across people's residences. Highly reliable portable and cost-effective samplers will be useful for such campaigns. This study aimed to investigate applicability of the Deployable Particulate Impact Sampler(DPIS), one of the compact impact samplers, to spatial monitoring campaigns of $PM_{2.5}$ in Seoul, Korea. The investigation focused on the consistency of $PM_{2.5}$ concentrations measured by DPISs compared to those by the Low-volume Cyclone sampler (LCS). LCS has operated at a fixed site in the Seoul National University Yeongeon campus, Seoul, Korea since 2003 and provided qualified $PM_{2.5}$ data. $PM_{2.5}$ sampling of DPISs was carried out at the same site from November 17, 2015 through February 3, 2016. $PM_{2.5}$ concentrations were quantified by the gravimetric method. Using a duplicated DPIS, we confirmed the reliability of DPIS by computing relative precision and mean square error-based R squared value ($R^2$). Relative precision was one minus the difference of measurements between two samplers relative to the sum. For accuracy, we compared $PM_{2.5}$ concentrations from four DPISs (DPIS_Tg, DPIS_To, DPIS_Qg, and DPIS_Qo) to those of LCS. Four samplers included two types of collection filters(Teflon, T; quartz, Q) and impaction discs(glass fiber filter, g; pre-oiled porous plastic disc, o). We assessed accuracy using accuracy value which is one minus the difference between DPIS and LCS $PM_{2.5}$ relative to LCS $PM_{2.5}$ in addition to $R^2$. DPIS showed high reliability (average precision=97.28%, $R^2=0.98$). Accuracy was generally high for all DPISs (average accuracy=83.78~88.88%, $R^2=0.89{\sim}0.93$) except for DPIS_Qg (77.35~78.35%, 0.82~0.84). Our results of high accuracy of DPIS compared to LCS suggested that DPIS will help the assessment of people's individual exposure to $PM_{2.5}$ in extensive spatial monitoring campaigns.

Microscopic Study of the Pig Peri-implantation Embryos (전자현미경에 의한 착상 전후 돼지수정란의 형태학적 변화에 관한 연구)

  • 김진회;백청순;이훈택;정길생
    • Korean Journal of Animal Reproduction
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    • v.18 no.2
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    • pp.141-150
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    • 1994
  • Morphological features of the interaction between the hatching blastocyst and implantation in pig were studied by electron microscopy. The observations extended from late blastocyst stage to the completion of trophoblastic erosion of the epithelium and early decidual transformation of the epithelium and early decidual transformation of the stromal cells. Between day 7 and 17 of pregnancy, blastocysts from 0.3 to 12 mm in diameter were flushed from the uterine horns of Dutch Landrace pigs. On the 7th of development in the pig blastocyst, the blastocyst shedded of the zona pellucida established the tips of microvilli and with bleb-like cytoplasmic protrusions of the epithelial cells. From day 11 on in pig embryo, the bilayered trophoblast undergoes a dramatic phase of elongation so that the initially spherical expanded blastocyst becomes tubular. In pig, close apposition to the uterine wall beg-ins at about 12 $^1$/$_2$ days and then attachment occurred during the afternoon of the 16th or 18th day post coitum. At this stage, embryonic loss compared with corpus luteum number is up to 40% of ovulated oocytes. Therefore, the implantation failture of these embryos may be mainly caused by morphological abnormality and failture of zona shedding.

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고대(古代) Egypt 복식(服飾)에 나타난 상징성(象徵性) - Tutankhamen 왕조(王朝)를 중심으로 -

  • Jeong, Heung-Suk
    • Journal of the Korean Society of Costume
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    • v.6
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    • pp.121-143
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    • 1982
  • Many studies have done on Egyptian Clothing because its unique characteristic culture. However, I was facinated by the exhibitions of Tutankhamen burial treasures which were shown in San Francisco and New York in 1978 and 1979. I found out myself that there are several interesting aspects of clothing to compare 18th dynasty king, Tutankhamun and other dynasties in Egyptian culture. Therefore, I tryed to analized the Egyptian clothing including accessaries with theigr symbols durin 18th dynasty King, Tutankhamun. The most of people were shocked and amazed when they toured the exhibition of Tutankhamun articles which were the most incredible burial treasures in existence today. The body of the King has been embalmed, bandaged and fitted in eight layers of coffins with pure gold mask to represent the god Osiris. Among eight layers of coffins, one is pure solid gold in mummiform, two of mummiforms are made of compact wood covered with sheets of gold and inlaid with multi-colored glass-paste and semi-precious stones. The Egyptian belived that the soul continued to exist throughout eternity if it had passed on examination of its deeds on earth at a "Last Judgement" presided over by Osiris. They also believed that the mummified body could exist in the tomb as a habitation that the soul could revisited. Thus a proper burial was vital for a full existence in the hereafter. They buried dead person in the sealed vault of the tomb with some of the possessions he had used during his life time, such as his furniture, clothing and jewels. In this studies, I've tried to research to various clothings, and accessories with their symbols used during 18th dynasty king, Tutankhamun. The studies are shown as: I) Clothings of Tutankhamun dynasity of Kalasiris, Sheath skirt. Gala skirt, Loin skirt, Hike and Dalmatic. The Dalmatic was first seen in this dynasty. Probably the Roman Christian borrowed the Dalmatica from Egyptian Dalmatic. No where has the same design at the period. II) Egyptian of 18th dynasty Tutankhamun wore big headdress, broad collar necklace passium, pendants, armlets, rings and earrings with very beautiful, exquisite handcraft. They seem the first people who wore earrings in Egyptian history. III) The symbols of decorated items vulture, lotus...Upper Egypt Uraeus, papyrus...Lower Egypt scaravaeus, Nile Riber...rebirth man(Ankh), +...eternal life solar disc, gold...sun ostrich-feather...nobleness God, Horus' eye...protection against enemy IV) Also Egyptian prefered the straight line and a right angle which were the basic principles of architectural arrangement.

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