• Journal of the Korean Ceramic Society
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• v.32 no.4
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• pp.462-470
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• 1995

The characteristics of spray-dried granules are important for dry pressing operation since they have great influences on die-filling, compaction ratio, and resulting green microstructure. An attempt was made to control granule morphology and the packing structure of fine Si3N4 particles in granules by adjusting suspension property. Mercury porosimetry was used to characterize the pore structures of both granules and green compacts. Finally, the effects of particle packing structure in granules and green microstructure on sintering behavior were investigated.

• Polymer(Korea)
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• v.29 no.3
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• pp.288-293
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• 2005

Osmotic granule system which is one of the drug delivery systems has been developed to improve manufacturing process and other problems of tablet osmotic systems. It consists of water swellable seed layer, nifedipine drug layer, and drug release controlled membrane layer and manufactured by fluidized bed coater. The granule size and mombrane thickness can be controlled by various amounts of seed and coating solution, respectively. It could be observed that the morphology of osmotic granule was different at each coating step as well as type of coating solution. The bigger the size of granule, the slower the release rate was observed due to decreasing the total specific surface wed of granule. Also, it was observed that the increase of membrane thickness was caused to retard the dissolution of nifedipine due to decreasing the water absorption rate. The drug solubility for dissolution media is greatly affected to nifedipine release. From these results, we assured that osmotic granule can be fabricated by fluidized bed coating methods, and the appropriate release profile could be controlled by the controlling of bead size, membrane thickness and dissolution media.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.987-991
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• 1997

Effect of morphology and granule size of crystalline D-sorbitol on texture of sugar-free chewing gum was investigated with different morphology of sorbitol such as a compact shaped P-type and a loose shaped S-type, and with different granule size such as 50 mesh, 80 mesh, and 100 mesh. The chewing gum including S-type sorbitol exhibited an increased flexibility and a decreased hardness as compared with that including P-type sorbitol. S-type sorbitol was chosen as a solid phase of sugar-free chewing gum because the consumer preferred a chewing gum with high flexibility and low hardness. The flexibility and hardness of chewing gum including S-type sorbitol were determined to be optimum at 80 mesh of the sorbitol size. The flexibility of the chewing gum including 80 mesh S-type sorbitol increased but the hardness decreased with increasing temperature.

• The Korean Journal of Ceramics
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• v.6 no.2
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• pp.96-99
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• 2000

Particle size of the cement raw materials is important not only in clinker burning but also in cement productivity. Model experiment was designed to investigate the effect of compressive grinding on cement raw materials and clinker granule. Compressive grinding was more efficient in reducing hard materials like quartz. Regression model was constructed to explain the effect of compressive grinding on the size reduction of cement raw materials and clinker.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.9
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• pp.24-36
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• 1996

In this paper, we discuss the errors in selectivity estimation using the multilevel grid file (MLGF). We first demonstrate that the estimatio errors stem from the uniformity assumption that records are uniformly distributed in their belonging region represented by an entry in a level of an MLGF directory. Bsed on this demonstration, we then investigate five factors affecting the accuracy of estimation: (1) the data distribution in a region (2) the number of records stored in an MLFG (3) the page size, (4) the query region size, and (5) the level of an MLFG directory. Next we present the tendancy of estimation errors according to the change of values for each factor through experiments. The results show that the errors decrease when (1) the distribution of records in a region becomes closer to the uniform one, (2) the number of records in an MLFG increases, (3) the page size decreases, (4) the query region size increases, and (5) the level of an MLFG directory employed as data distribution information becomes lower. After the definition of the granule ratio, the core formula representing the basic relationship between the estimation errors and the above five factors, we finally examine the change of estimation errors according to the change of the values for the granule ratio through experiments. The results indicate that errors tend to be similar depending on the values for the granule ratio regardless of the various changes of the values for the five factors. factors affecting the accuracy of estimation:

• The Korean Journal of Pain
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• v.11 no.1
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• pp.7-22
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• 1998

The development of the superior cervical ganglion was studied by electron microscopic method in human fetuses ranging from 40 mm to 260 mm of crown-rump length(10 to 30 weeks of gestational age). At 40 mm fetus, the superior cervical ganglion was composed of clusters of undifferentiated cell, primitive neuroblast, primitive supporting cell, and unmyelinated fibers. At 70 mm fetus, the neuroblasts and their processes were ensheated by the bodies or processes of satellite cells. The cytoplasm of the neuroblast contained rough endoplasmic reticulum, mitochondria, Golgi complex, Nissl bodies and dense-cored vesicles. As the neuroblasts grew and differentiated dense-cored vesicles moved away from perikaryal cytoplasm into developing processes. Synaptic contacts between the cholinergic axon and dendrites of postganglionic neuron and a few axosomatic synapses were first observed at 70 mm fetus. At 90 mm fetus the superior cervical ganglion consisted of neuroblasts, satellite cells, granule-containing cells, and unmyelinated nerve fibers. The ganglion cells increased somewhat in numbers and size by 150 mm fetus. Further differentiation resulted in the formation of young ganglion cells, whose cytoplasm was densely filled with cell organelles. During next prenatal stage up to 260 mm fetus, the cytoplasm of the ganglion cells contained except for large pigment granules, all intracytoplasmic structures which were also found in mature superior cervical ganglion. A great number of synaptic contact zones between the cholinergic preganglionic axon and the dendrites of the postganglionic neuron were observed and a few axosomatic synapses were also observed. Two morphological types of the granule-containing cells in the superior cervical ganglion were first identified at 90 mm fetus. Type I granule-containing cell occurred in solitary, whereas type II tended to appeared in clusters near the blood capillaries. Synaptic contacts were first found on the solitary granule-containing cell at 150 mm fetus. Synaptic contacts between the soma of type I granule-containing cells and preganglionic axon termials were observed. In addition, synaptic junctions between the processes of the granule-containing cells and dendrites of postganglionic neuron were also observed from 150 mm fetus onward. In conclusion, superior cervical ganglion cells and granule-containing cells arise from a common undifferentiated cell precursor of neural crest. The granule-containg cells exhibit a local modulatory feedback system in the superior cervical ganglion and may serve as interneurons between the preganglionic and postganglionic cells.

• The Korean Journal of Zoology
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• v.28 no.3
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• pp.194-208
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• 1985

The ultrastructure of the integumental epidermis of Korean planaria (Dugesia japonica) is studied by light microscope, scanning electron microscope and transmission electron microscope. The planaria has mono-layered integumental epidermis in which most of cells exhibit irregularly columnar shape. The epidermal cells of the integument are classified into six types on the basis of cytochemical and ultrastructural characteristics. 1) Ciliated epithelial cells: These cells have cilia in their free surfaces. The axonemes of cilia exhibits fundamental 9+2 microtubular pattern. 2) Eosinophilic cells: These cells contain a few large eosinophilic granules. The core of eosinophilic granule is consisted of sparsely dispersed fibrillar structures in relatively electron-lucent ground material. 3) Mucous cells: These cells are filled with irregularly shaped, PAS-positive mucous granules which have an average size of $0.8\\times0.3 \\muM$. 4) Rhabdite-forming cells: These cells possess a few strongly-eosinophilic large rhabdite granules. The rhabdite granules are synthesized either in the rhabdite-forming cells which constitute integumental epidermis or in the corresponding cells which are developed in the parenchyma and later transferred to epidermal cells of integumental epidermis through basement membrane. 5) A-type of basophilic granule cells: These granule cells possess round or irregularly-shaped granules which are strongly stained with Alcian blue. These electron-dense granules have an average size of $1.5\\times1.0 \\muM$. This type of cells is derived from parenchymal tissue. 6) B-type of basophilic granule cells: These basophilic granule cells with PAS-positive granules, are found in the epidermis of lateral body wall. The granules, which are about $0.7\\times0.4 \\muM$ in size, occupying most part of this cell type are originated from the parenchyma.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.3
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• pp.226-231
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• 2008

Cu/Fe/$Al_2O_3$ granules with various sizes have been prepared by a combination of sol-gel and oil drop method for the use in sulfur trioxide decomposition, a subcycle in thermochemical sulfur-iodine cycle to split water in the hydrogen and oxygen. The size of composite granules have been mainly changed by the flow-rate of the gel mixture before dropping in the synthesis. The structural properties of the samples were comparable with granule size. In the reaction, the catalytic activity was enhanced by decreasing size in the entire reaction temperature ranges.

• Journal of the Korea Convergence Society
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• v.8 no.8
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• pp.197-202
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• 2017

Three-dimensional melanin granules of mummy's hair analyzed using high voltage electron microscopy at 1250kV. The melanin granules in the cortex of mummy's hair located in close proximity to the outer of cortex in the adjacent place of the cuticles. A lot of melanin granule performed in this area. It is a distinguished difference from modern human. While it rotated up to 60 degree counter-clockwise and taken a photo per one degree using high voltage electron microscopy. The melanin granule displayed with long elliptical and variable at the size. The size of granule is measured from $0.3{\sim}0.6{\mu}m$ in minimum diameter and $0.5{\sim}1{\mu}m$ in maximum diameter. Conclusionally, high voltage electron microscope has higher resolution and penetration power than conventional transmission electron microscope that could be load biological thick specimen.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.356-364
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• 1998

The dependence of green and sintered densities of Zirconia-Toughened Alumina ($ZTA:\;Al_2O_3/\;15\;vol{%}\;ZrO_2$) on the properties of spray-dried granules was studied thoroughly to establish the optimum compaction condition leading to high reproducibility in the light of sintered density. The sphericity, mean size, degree of hollow occurrence and moisture content of spray-dried granules were largely different in between the granule containing binder and the ones with no binder. The effect of these differences in the characteristic of granules on the compaction behavior was examined in terms of the compaction pressure from 80 MPa to 120 MPa 10 MPa increment and the compaction method, i.e., uniaxial and cold isostatic pressing. This work confirmed that the reproducibility of sintered density caused by the variation of granule property could be improved by the optimization of compaction process. The variation of sintered density was controlled within 1 % deviation by compacting the granules under a relatively low pressure of 80 MPa in an uniaxial forming and subsequent cold isostatic pressing at high pressure of 500 MPa.