• Applied Microscopy
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• v.28 no.3
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• pp.345-362
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• 1998

In order to the comparative morphological study of the non-ciliated and ciliated epithelial cells, and to elucidate the process of degeneration of non-ciliated epithelial cell of the ductus epididymidis, Korean striped field mouse, Apodemus agrarius coreae was examined with light and transmission electron microscopes. The morphological characteristics of non-ciliated epithelial cell, the cell types of the caput epididymidis (Cp), corpus epididymidis (Cr) and cauda epididymidis (Cu) were long-columnar, short-columnar and short-cuboudal, respectively. The mitochondria and rough endoplasmic reticulum tended to be broken as they immigrated from Cp to the Cu. The Golgi acted vigorously at the Cp, but the Golgi was inactive in Cr and Cu. The secretory vesicles and lysosomes were increased gradually from Cp to the Cu. The process of degeneration of the non-ciliated epithelial cells observed in the Cp, Cr and Cu epididymidis. The increase of the non-ciliated epithelial cells, and its degeneration were observed more often from Cp to the Cu. The morphological characteristics of the ciliated epithelial cells, the cell types of the Cp, Cr and Cu were long-columnar, short-columnar and short-cuboudal, respecptively like the non-ciliated epithelial cells. The stereocilia was long and slender at the Cp and Cr, while Cu was very short. The pinocytotic vesicles and absorptive vesicles were increased from the Cp to the Cu. Numerous disintergrated products was existed at the Cr including the Cp, but Cu were not observed. A significant amount of lysosomes existed at the Cp and Cr epithelial cells, but they were not observed in Cu epithelial cells.

• Applied Microscopy
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• v.34 no.3
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• pp.199-209
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• 2004

The migut epitheluim of the last instar larva in the mosquito larvae, Anopheles sinensis was observed with electron microscopes. The midgut epitheluim of the mosquito larva is composed of a single-layered columnar absorptive cells, regenerative cells and secretory granular cells. The free surface of the columnar absorptive cells has a regular array of microvilli 'brush border', while cell membranes close to the basal lamina are extrmely infolded and a lot of mitochondria are concentrated in those processes. The columnar absorptive cells also contain cell organelles expected to be found in absorptive cell. Midgut regenerative cells which are positioned basally in the epithelium form the groups, which are called 'nidi', composed of 1 or $2{\sim}3$ cells, they show darker appearance than the columnar absoptive cells. The secretory granular cells contain numerous electron dense granules, $200{\sim}400$ nm in diameter. The cone shaped secretory granular cells are located in the basal portion of the midgut epitheluim. The epithelium is surrounded by the subepithelial space and muscle bundles. The subepithelial space, which is filled with fibrous connective tissue, is innervated by many axon cells and tracheoles.

• Korean Journal of Veterinary Research
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• v.35 no.1
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• pp.11-17
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• 1995

The development of colon in fetuses between 60, 90, 120 days of gestation and neonates of Korean native goats was investigated by light scanning electron microscopy. The results were summarized as follows : 1. The colonic wall appeared to be differentiated into the epithelium, lamina propria, submucosa, tunica muscularis and serosa in 60-day-old fetus. 2. The epithelium of the colonic villi was stratified in some areas and simple columnar in others at 60- and 90day-old fetus but was only observed simple columnar epithelium at 120-day-old fetus. 3. The goblet cells and the intestinal glands appeared in the colonic mucosa at 90 days of gestation and continued gradually to increase in number during gestation. 4. The well-developed villi of the colon appeared in columnar shape at 60 days of gestation and increased in length and width until 90 days of gestation but the villi appeared to be shorter and degenerated after 120 days of gestation. At birth only the rudiment trace of the villi remained. 5. The tunical muscularis of the colon was continuously developed during gestation period. The inner circular and outer longitudinal muscle layers were distinguishly observed in the colon of 90-day-old fetuses. 6. Scanning electron microscopically, the colonic villi developed in columnar shape or finger-like of fetuses at 60 days of gestation. The of the colonic villi became degenerated after 120 days of gestation. At birth only the rudiment trace of villi remained.

• Polymer(Korea)
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• v.30 no.5
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• pp.373-379
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• 2006

Polymerizable discotic liquid crystals containing diacetylene and acryloyl groups were formed through hydrogen bonding between phloroglucinol core and polymerizable pyridine derivatives, and their photopolymerization behavior was investigated. The discotic complexes exhibited discotic columnar and rectangular columnar mesophases depending on the number of aromatic rings. Photopolymerization of the discotic complexes was carried out by UV irradiation in the liquid crystalline state. IR and UV-Vis spectroscopy affirmed that diacetylene and acryloyl groups were selectively Polymerized, and that crosslinked polymers containing short conjugated diacetylene oligomers were produced by 1,4-addition. X-ray diffraction experiment showed that the columnar order in the discotic complex containing phenyl-pyridine moiety was maintained after photopolymerization, and that the rectangular columnar order in he discotic Complex with biphenyl units was changed to the lamellar order.

• The Korean Journal of Zoology
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• v.28 no.3
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• pp.151-165
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• 1985

The morphological changes of the midgut epithelium during the metamorphosis of pine caterpillar are observed with light and electron microscope, being divided into 5 stages from the 8th instar larva to just after pupation. The midgut epithelium of 8th instar larva is composed of columnar cell, goblet cell, regenerative cell, and endocrine cell. The secretorials are arranged on the nuclear membrane in the columnar cell of the midgut epithelium in the 8th instar larva, and lysosomes are augmented in the apical portion. Cytoplasmic extrusions are observed in the apical surface of columnar cell but they have no cell organells. Nucleus, mitochondria, rER, Golgi complex, and free ribsomes are observed in the regenerative cell. Regenerative cells are differentiated into the form of goblet cell, and vacuoles are gradually increased in the cytoplasm. Just pupa stage, the materials, which appears to be mainly composed of Ca, are observed in the circular form and goblet cavity of regenerative cell are detached to lumen. As a result, it reflects the process of the degeneration of the midgut epithelium that lysosomes are gradually augmented in the columnar cell, that nuclear materials are removed to cytoplasm, and that cytoplasmic extrusions are observed in the apical surface. And though regenerative cells are differentiated into the form of the goblet cell, it is believed that goblet cavity is detached from regenerative cell to the lumen and midgut epithelium of pupa stage is formed.

• Korean Journal of Veterinary Research
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• v.14 no.2
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• pp.159-171
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• 1974

Histological and histochemical studies were made on the lining epithelia of the various ducts in epidymis of the Rooster and absorptive function of the canal epithelial cells in the Rooster epididymis were also investigated after administration of India ink. The results obtained were summerized as follows; 1. Epihtelium lining the rate testis was mainaly composed of single later of cuboidal cells, and was partially composed of flattened squamous or low columnar cells. Efferential ductules were characterized by having many villous projections orrfolds which extened into the lumen, and were lined by stereociliated pseudostratified epithelium which consisted of manily ciliated columnar cells, a few scattered clear cells and basal cells. Connecting ductules were lined by ciliated pseudostriatified colummnar epithelium in which ciliated columnar cells, clear cells and basal cells were noted. Epididymal ducts were lined by pseudostratified epidhelium in which columnar and basal cells were noted. 2. PAS-granules, saliva resistant were noted mainly in the epithelial cells of efferential and connecting ductules. 3. Sudan black B stained heavily the granules in the epithelial cells of sufferential and connecting ductules. 4. The granules reactive to acid phosphatase most abundant in the epithelial cells of efferential ductules and were lesser amount in the epithelial cells of connecting ductules where as very few or no granules were seen in the rest of the ducts. 5. Alkaline phosphatase activity was most prominent but discontinuous in the luminal surface of the epithelium of efferential ductules and less marked in the connecting ductless. No enzyme activity was noted in the canal epithelium of epididyml duct. 6. India ink granules were most numerous in the epithlial cells of efferential ductules and were a few in connecting ductules. Very few or no granules of India ink were noted in the other types of the ducts. India ink granules in the epithelium increased gradually as the time after the administration of India ink (one up to twenty-nine hours) has proceeded. From those results it is suggested that epithelial cells of efferential and connecting ductules have active absorptive function, whereas the rest of duct system in the epididymis of the Rooster may be the mere pathway of the seminal fluid without significant modification of its constituents.

• The Journal of Engineering Geology
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• v.26 no.3
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• pp.383-392
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• 2016

This study is to evaluate the physical and mechanical properties on the Ipseok-dae columnar joints of Mt. Mudeung National Park. For these purposes, physical and mechanical properties as well as discontinuity property on the Mudeungsan tuff, measurement of vibration and local meteorology around columnar joints, and ground deformation by self-weight of columnar joints were examined. For the physical and mechanical properties, average values were respectively 0.65% for porosity, 2.69 for specific gravity, 2.68 g/cm³ for density, and 2411 m/s for primary velocity, 323 MPa for uniaxial compressive strength, 81 GPa Young's modulus, and 0.25 for Poisson's ratio. For the joint shear test, average values were respectively 3.15 GPa/m for normal stiffness, 0.38 GPa/m for shear stiffness, 0.50 MPa for cohesion, and 35° for internal friction angle. The JRC standard and JRC chart was in the range of 4~6, and 1~1.5, respectively. The rebound value Q of silver schmidt hammer was 57 (≒ 90 MPa). It corresponds 20% of the uniaxial compressive strength of intact rock. The maximum vibration value around the Ipseok=dae columnar joints was in the range of 0.57 PPV (mm/s)~2.35 PPV (mm/s). The local meteorology of surface temperature, air temperature, humidity, and wind on and around columnar joints appeared to have been greatly influenced the weather on the day of measurement. For the numerical analysis of ground deformation due to its self-weight of the Ipseok-dae columnar joints, the maximum displacement of the right ground shows when the ground distance is approximately 2 m, while drastically decreased by 2~4 m, thereafter was insignificant. The maximum displacement of the middle ground shows when the ground distance is approximately 0~2 m, while drastically decreased by 3~10 m, thereafter was insignificant. The maximum displacement of the left ground shows when the ground distance is approximately 5~6 m, while drastically decreased by 6~10 m, thereafter was insignificant.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.45-50
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• 2000

We have investigated the influence of columnar defects (CD) on the vortex dynamics in pristine and iodine-intercalated Bi$_2$Sr$_2$CaCu$_2$O$_{8+{\delta}} single crystals from do SQUID magnetization measurements. Especially, the temperature dependence of the irreversibility fields, H$_{irr}$(T), were studied. Anisotropy ratio ${\gamma}$, estimated from the fitting to the 2-dimensional melting model (A. Schilling et al., Phys. Rev. Lett. 71 1899 (1993)) in higher fields than the matching field B$_{\phi}$ at low temperature region, turns out to be decreased by the iodine-intercalation and additionally by the heavy-ion irradiation.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.5
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• pp.242-245
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• 2009

AlN crystals were grown by a sublimation process without seed crystals and the growth morphology of them was characterized. The grown AlN crystals were a polycrystalline phase, which had a diameter of $60\sim200\;{\mu}m$ and were grown with a growth rate of $0.2\sim0.5\;{\mu}n/hr$. It was observed that the as-grown crystals had a hexagonal crystal structure and revealed that these crystals were grown with a morphology of columnar morphology in the initial stage of the growth before they were enlarged in a way of a lateral growth behavior in the final stage. On the surface, a lot of pinholes were observed on the surface of crystals grown. The evolution of a growth morphology was characterized by optical and scanning electron microscopic observation.

• KIEE International Transactions on Electrophysics and Applications
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• v.11C no.2
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• pp.32-36
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• 2001

We investigate the surface order, defects and morphology of hexagonal columnar mesophases, Having a crown ether at one end which forms the center of the column and three fluorinated tails at the other, The orientation of the columns was successfully controlled by surface anchoring: Columns were aligned perpendicularly to an evaporated carbon surface, and the planar alignment do asymmetric compounds was induced by a water surface. TEM images show that there is a high degree of perfection in the packing do the cylinders. The hexagonal columnar mesophase (F(sub)h) was confirmed by direct images and the corresponding electron diffractions, where ordered cylindrical moieties are packed on a hexagonal lattice. The column of 12F8-ABG-15C5 was much straighter, compared with that of 12F8-AG-B15C5, resulting from the degrees of regular stacking. Elementary edge dislocation, grain boundary and +1/2 disclination have been observed, although the defects are generally rare.