• Applied Microscopy
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• v.31 no.1
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• pp.85-90
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• 2001

The ultrastructures of the fertilized egg envelope from long nose barbel, Hemibarbus longirostris belong to Cyprinidae was studied using scanning and transmission electron microscopes. The fertilized egg was adhesive type, have a single micropyle resembling the pathway of sperm in the area of the animal pole. An outer surface of the fertilized egg envelope was arranged by adhesive structures irregularly. In section of fertilized egg, the egg envelope consists of two layers, an outer adhesive twofold layer with mushroom-like cluster and an inner lamellae layer consisting of four layers. These ultrastructural characters of fertilized egg envelope from long nose barbel can be utilized in taxonomy of teleost.

• The Korean Journal of Malacology
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• v.27 no.1
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• pp.69-76
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• 2011

Gill morphology and ultrastructure of the spiny top shell, Batillus cornutus were described using light and electron microscopy (SEM and TEM). The spiny top shell, Batillus cornutus has bipectinate gill. The epithelial layer of gill filament was simple and composed of columnar epithelium, ciliated cell, mitochondria-rich cell and secretory cell. Microvilli were well-developed on the free surface of columnar epithelial cell. The epithelial cells are connected to the neighboring cells with intercelluar junctions at the apico-lateral surface. The cilia and microvilli were commonly observed on the free surface of ciliated cell. Tubular mitochondria appeared in the apical cytoplasm, and connected ciliary rootlet. Mitochondria-rich cells contained a oval-shaped nucleus in the basal area. And majority of cytoplasm was occupied by well-developed mitochondria. Result of AB-PAS (pH 2.5) and AF-AB reaction showed that secretory cells contained mainly acidic carboxylated mucosubstances. Secretory cells are unicellular glands and can be divided into four types (A, B, C and D) depending on the cell shape and ultrastructure of secretory granules.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.26-26
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• 2003

본 연구에서는 누적압연접합공정(ARB)을 통하여 5052 알루미늄 합금의 결정립을 약 0.2$\mu\textrm{m}$ 크기로 미세화 하였다. 누적압연에 의한 변형량 증가에 따른 미세 조직 변화와 결정립 간의 상대적인 방위각 차이를 TEM을 이용하여 관찰하였다. 누적 변형량을 함수로 상온 인장특성을 분석하였고, 초미세립 소재를 후속 열처리한 후 미세 조직 변화를 관찰하여 제조된 초미세립 소재의 열적 안정성을 평가하였다. 상온 대기 중에서 pin-on-disk 형태의 마멸시험기를 사용하여 초미세립 소재의 미끄럼 마멸시험을 변형량과 하중을 변수로 행하였다. 강소성 변형에 의해 제조된 5052 알루미늄 합금 소재의 마멸저항성은 강소성 변형 전과 비교하여 소재의 경도가 크게 증가하였음에도 불구하고 오히려 감소하였다. 마멸시험 후 마멸면의 SEM, 마멸단면의 OM 관찰과 마멸면 직하의 깊이에 따른 경도측정을 통하여 초미세립 소재의 마멸기구를 분석하였고 마멸표면의 변형 층을 관찰하였다. 또한 마멸면 직하 조직의 TEM 관찰을 통해서 마멸시험 중의 미세 조직 변화를 연구하였다.

• Journal of the Korean Ceramic Society
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• v.37 no.9
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• pp.909-914
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• 2000

반응금속 침투법으로 제조한 $Al_2$O$_3$/Al 복합체의 파괴특성과 손상 내구성을 침투방향성에 따라 관찰하였으며, 복합체는 $Al_2$O$_3$단일상보다 향상된 파괴인성과 Al 단일상보다 높은 경도값을 나타내었다. Vickers 압입법을 사용한 복합체의 손상형태에서는 침투방향에 따른 각각의 미세구조에 의해 상이한 특성을 나타내었으며, 헤르찌안 압입법을 사용한 복합체의 손상거동은 $Al_2$O$_3$과 Al의 중간거동을 나타내었다. 헤르찌안 압입 후 강도저하시험으로 복합체가 갖는 우수한 결함저항성을 관찰할 수 있었으며, 높은 헤르찌안 하중에서는 복합체의 강도저하 특성이 복합체의 미세구조에 의존함을 관찰할 수 있었다. 이와 함께 복합체에서의 반응금속 침투방향성, 미세구조 그리고 손상 내구성 사이 상호연관성에 대해 논의하였다.

• The Korean Journal of Zoology
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• v.37 no.2
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• pp.203-212
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• 1994

별불가사리 난자형성 중 난모세포(직경 7-l7O Um) 표면의 구조적 변화를 투과 전자현미경으로 관찰하였다. 직경 25-855 Um의 난모세포에서 'endocvtosis'와 관련된 구조인 coated pit, coated vesicle과 내포소낭이 존재하였으며. 내포소낭은 난황립과 융합하였다. 특히, 이러한 융합은 직경 130-155 Um의 난모세포에서 많이 관찰되었다 난자형성 초기에 난모세포의 미세융모는 세포막을 따라 무질서하게 분포하고. 인접한 세포와 맞닿아 있었다. 직경 15 Um에서 65 Um에 이르는 난모세포는 세포막 부위에 따라서 미세융모의 굵기와 길이, 그리고 형태가 다르게 나타났고, 직경 100 Um 이상의 난모세포에서는 잘 발달된 미세음모가 난뢍층에 존재하였다 여포세포로부터 나온 돌기는 직경 7 Um의 난모세포와 난자형성 후기의 난모세포에서 난황층을 윤고 세포막과 닿아 'junctional complex'를 형성하였다. 이와같은 난모세포 표면의 다양한 구조적 변화는 난모세포의 세포막을 통한 물질투과 기능의 분화와 관련이 있을 것으로 생각된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.468-468
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• 2022

기후변화 및 도시열섬화 등의 영향으로 여름철 폭염 및 봄·겨울철 미세먼지 영향은 증가하고 있다. 최근 40년(1980년~2019년) 동안 서울의 최고기온은 2.2℃ 증가하였으며, 이는 전국에서 두 번째로 높은 증가추세이다. 서울시는 도시열섬과 미세먼지 저감을 일환으로 '스마트 물순환도시 조성사업'을 추진하고 있다. 본 연구에서는 서울형 물순환도시 소개와 더불어 쿨링포그, 쿨루프, 클린로드시스템, 투수블록, 식생수로 빗물정원 등 수자원을 활용한 기술을 조사하고 문헌조사를 통해 저감효과를 비교분석하였다. 이는 수자원을 활용한 도시 형태 개선으로 쾌적한 도시환경 조성 뿐만 아니라 시민의 행복과 만족감 증대에 기여할 것으로 판단되며, 향후 서울형 스마트 물순환도시 보다 많은 지역에 확대운영 할 수 되도록 기여하고자 한다.

• Korean Journal of Animal Reproduction
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• v.25 no.3
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• pp.237-242
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• 2001

We recently demonstrated that both linear- and supercoil-form B1/B2 SINE (short interspersed elements) sequences could increase an integration frequency of a reporter gene in preimplatation mouse embryos. In those reports, when either a control or SINE-flanked DNA was separately applied to microinjection, the proportions of $\beta$-gal positives were 16% and 63%, respectively, in linear-form DNA, and 6% and 25%, respectively, in circular-form DNA. Here, we examined the contribution of a circular-form DNA moiety to integration frequency by using a mixed-farm (linear and circular-form) DNA in microinjection. When examined in the blastocyst stage, the proportion of $\beta$-gal-positive embryos was 17.3% and 46.6% in control and SINE-flanked DNA, respectively. These results suggest that there is little contribution of circular-form DNA moiety to the resultant integration frequency, and that the majority of the integration events are mediated through a linear conformation of vector DNA. In addition, some clues on integration process could be obtained from the analysis of microinjection results.

• Journal of Embryo Transfer
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• v.19 no.3
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• pp.283-289
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• 2004

This study was conducted to determine the effects of incubation time after cooling on mouse meiotic spindle and chromosome alignment and the optimal incubation time for their restoration. Oocytes at the metaphase II were obtained from superovulated mice. Control oocytes were held at 37$^{\circ}C$ during the experiment. Oocytes were rapidly cooled to $0^{\circ}C$, held for 30 minutes, warmed and incubated at 37$^{\circ}C$ for 5, 15, 30, 60 and 120 minutes, respectively. The morphological features of spindle and chromosomes in oocytes were evaluated by immunofluorescent staining. Meiotic spindle of control oocytes exhibited a normal-looking bipolar configuration(barrel-shaped) and highly fluorescent microtubles. The chromosomes were clustered in a discrete bundles at metaphase plate. Disassembly of meiotic spindle and chromosome dispersion were occurred immediately after chilling of oocyte. Fluorescence intensity index(FIS), normal chromosomes aligned and normal spindle configuration were compared according to incubation time at 37$^{\circ}C$. Restoration of a barrel-shaped spindle and normal chromosome alignment was occurring after 5 minutes incubation at 37$^{\circ}C$, improved as a incubation time increased, and decreased gradually after 120 minutes incubation(P<0.05). The optimal incubation time for restoration of meiotic spindle and chromosomes in cooled oocytes was 60 minutes.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.5
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• pp.293-303
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• 2004

This experiment was conducted to investigate the direction or orientation of clay particle movement in argillic horizons (Bt) for clarifying the soil classification of soils. Soil samples were collected from 22 soil series containing Bt horizons. Physical and chemical characteristics and mineral and chemical compositions of clay in the soils were analyzed. Micoromorphological characteristics of the Bt horizons were also investigated with thin sections of the natural undisturbed and oriented soil samples. Average clay content in the Bt horizons was 28% and 1.33 times higher comparing to that in the surface layer. Soil pH was higher, but cation exchange capacity (CEC) and organic matter content were lower in Bt horizon than those in the surface layer. There was an evidence of clay accumulation in Bt horizons of all soil series examined except Bangog series. Although there was an increase of clay content in the horizons in Bangog series, the clay was not originated from illuviation process. The translocation of clay was in the order of an 2:1 expandable clay minerals > 2:1 non-expandable clay minerals > 1:1 clay minerals. The illuvial substances in argillic horizon were composed with clay, amorphous iron and opaque mineral. The micoromorphological features of Bt horizon were void coating, channel infilling and grain coating. There was an apparent boundary between clay coating and the groundmass in residuum and colluvium, but Bt horizon of alluvium was composed of a skew plane amputated by the physical operation.

• Journal of Soil and Groundwater Environment
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• v.9 no.4
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• pp.52-61
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• 2004

In order to remediate soils contaminated with oxyanionic As and cationic Zn and Ni through the pilot-scale acid washing, the effectiveness of acid washing and the properties of contaminated soils, fine soil particle and dissolved contaminants were evaluated. $H_{2}SO_4\;and\;H_{3}PO_4$ washing at pH $2{\sim}3$ enhanced the removal of As by the presence of competitive oxyanions and HCl washing effectively removed simultaneously As, Zn and Ni. The effectiveness of soil washing was little enhanced above the critical reaction time, and the carbonate, Fe/Mn oxide and organic/sulfides associated fraction were dominantly removed. The washing of coarse soil particles was highly efficient, but that of fine soil particles($<74{\mu}m$) was recalcitrant due to the enrichment with contaminants. Moreover, the physical separation of fine particles($<149{\mu}m$) enhanced the overall efficiency of soil washing. Therefore, both chemical extraction and separation of fine soil particles showed the high effectiveness of soil washing in the intersection point to minimize the amount of fine soil particles and to maximize the chemical extraction of contaminants.