• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.288-288
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• 1999

• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.256-256
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• 2002

• Proceedings of the Korean Nuclear Society Conference
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• 2003.10a
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• pp.361.1-361.1
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• 2003

• Applied Microscopy
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• v.38 no.2
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• pp.89-96
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• 2008

Dolomedes spiders of the family Pisauridae are one of free wandering spiders with semi-aquatic habitation. They do not build web for prey-hunting but build a nursery web for spiderlings. This paper describes the fine structure of the silkspinning spigots of the fishing spider Dolomedes sulfureus revealed by the field emission scanning electron microscope (FESEM). The fishing spider Dolomedes sulfureus possesses only three types of silk glands which connected through the typical spinning tubes on the spinnerets. The silk spigots of this spider were identified as three groups: ampullates, pyriforms and aciniforms. Two pairs of major ampullate glands send secretory ductules to the anterior spinnerets, and another two pairs (or $1{\sim}2$ pairs in males) of minor ampullate glands supply the middle spinnerets. In addition, the pyriform glands feed silk into the anterior spinnerets ($62{\sim}68$ pairs in females and $45{\sim}50$ pairs in males), and the aciniforms send ductules to the middle ($33{\sim}40$ pairs in females and $18{\sim}25$ pairs in males) and the posterior spinnerets ($42{\sim}50$ pairs in females and $24{\sim}28$ pairs in males). Among these, the ampullate one is the most predominate gland in both sexes.

• Journal of the Korean Society of Propulsion Engineers
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• v.1 no.1
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• pp.82-88
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• 1997

The goal is to assess the effect of fatigue loading on mechanical properties of Fiberite 934/T300 laminates of pressure vessel using the recent variational mechanics analysis. This analysis has been useful in providing fracture mechanics interpretation of matrix microcracking in cross-ply laminates. This paper describes using the new energy release rate analysis for a fracture mechanics based interpretation of microcrack formation during fatigue loading. The master plot by modified Paris-law gives a complete characterization of a material system's resistance to microcrack formation.

• Journal of the Korean Ceramic Society
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• v.38 no.4
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• pp.388-392
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• 2001

저압 화학증착법으로 등방성 흑연 기판 위에 탄화규소 증착층을 제조하였다. 반응관 내부의 전체 반응압력(이하 반응압력)을 1.5torr-100torr로 변화시켜 증착층의 미세구조에 미치는 영향을 조사하였다. 120$0^{\circ}C$ 이하에서는 전체 반응압력 변화에 상관없이 일정하게 낮은 증착속도를 보였으며, 미세구조는 round-top 구조를 나타내었다. 125$0^{\circ}C$, 10torr를 기준으로 증착온도와 반응압력이 증가함에 따라 미세구조가 round-top 구조에서 angular, faceted 구조로 변하였으며, 이는 반응압력이 증가함에 따라 증착기구가 표면반응에서 물질전달로 전이하였기 때문이다.

• Applied Microscopy
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• v.31 no.4
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• pp.375-383
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• 2001

To understand the fine structure of Korean bat livers , the authors investigated the liver of four Korean bats; Rhinolephus ferrumequinum korai, Myotis macrodactylus, Myotis dauhentonii ussrinesis, and Murina leucogaster intermedia by transmission electron microscopy. The hepatocytes of Rhinolophus ferrumequinum korai had large-sized mitochondria and many peroxisomes. In the Myotis macrodactylus, juctional completes, especially desmosomes, were well developed. The Myotis daubentonii ussrinesis had many glycogen particles in the cytoplasm. Also, the space of Disse and sinusoidal spare was filled with amorphous materials. In the Murina leucogaster intemedia, basement membrane was prominent in the sinusoid, and no Kupffer and Ito cells were observed These results suggest the characteristic differences in the liver ultrastructure among Korean bats.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.546-549
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• 2005

Micro EDM milling using deionized water as dielectric fluid was investigated. After machining micro grooves using deionized water with different voltage. capacitance. and resistivity of deionized water, machining characteristics were investigated. The wear of a tool electrode and the machining time can be reduced by using deionized water instead of kerosene. Micro hemispheres were machined in deionized water and kerosene and their machining characteristics were compared.

• Applied Microscopy
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• v.31 no.2
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• pp.157-165
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• 2001

Sertoli cells in the normal adult testis are nondividing cells, which are relatively inconspicuous on cross section of the seminiferous tubule and comprise about 10% to 15% of the tubular cellular elements. Ultrastructurally, Sertoli cells have characteristic nucleoli, plasma membrane, and cytoplasmic components. The plasma membrane has two types of intercellular junctions which are developed at puberty: junctions between adjacent Sertoli cells and Sertoli cell-germ ceil junction. However, the ultrastructural findings of Sertoli cells in human fetus is not fully elucidate yet. In the present study, human fetal testes ($14\sim27$ weeks) obtained from artificially induced abortions legally without gross malformation were studied using transmission electron microscopy to make clear the differentiation process of Sertoli cells in human. In human fetal testes from 14 weeks to 27 weeks, the cell junctions of Sertoli-germ cells and Sertoli-Sertoli cells are desmosome like structure and not tight junction or desmosome. The Overall intracytoplasmic organelles of Sertoli cells are relatively sparse. The mitochondrias are relatively abundant but no developed cristae. And the rough endoplasmic reticuli are abundant and smooth endoplasmic reticuli are sparse. The amount of lipid droplets are regularly observed in human fetal Sertoli cells. No microfilaments or Charcot-Bottcher's crystalloids are present. From the results, Sertoli cells in human fetal testes are somewhat different ultrastructural findings with puberty or adult. However, to make clear the differentiation process of Sertoli cells in human, further study for 28 weeks to puberty is required.

• The Journal of the Acoustical Society of Korea
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• v.34 no.2
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• pp.108-116
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• 2015

An acoustic vector sensor is a device that is capable of measuring the direction of wave propagation and the acoustic pressure. In this paper, the modeling of micro-cantilever sensor for the vector sensor are proposed by consideration of acoustic phenomenon in water. Two models based on unimorph structure are proposed in this paper and corresponding transfer function which describes the relation between input pressure wave and output voltage depending on incidence angle and frequency of pressure wave is derived based on lumped model. It has been shown that very thin and flexible micro-cantilever can be used to measure directly the particle velocity component in water.