• Applied Microscopy
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• v.24 no.1
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• pp.1-10
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• 1994

The integumental secretory structure is exocrine unicellular gland located in the epidermis of goldfish, Carassius auratus, and divided into two groups, mucous and granular cells. By the histochemical studies of integumental secretions the mucos cells reacted for acidic polysaccharides, and the granular cells for neutral glycoprotein. According to concentration of the secretion the integumental mucous are gradually sulphated. The mucous cells are typical form of goblet cell located in the upper region of the epidermis, and membrane bounded vesicles of the mucous are observed several size and electron densities by the cellular differentiation. The granular cells in middle and lower epidermis are present syncitial forms occasionally, and contain electron dense granules sized $1.0{\mu}m$ which are accumulated in cytoplasmic process held the cells to the basal lamina. The precursors of the integumental secretory materials are originated from the rough endoplasmic reticulum and next transported through the Golgi apparatus as a form of membrane bounded vesicles. After accomplish this process mature secretions are extruded to integumental surface by the mechanism of merocrine secretion in response to nerve stimulations respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5C
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• pp.183-190
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• 2009

It is necessary to predict the deformation and stresses on soils to establish the nonlinear stress-strain relationship of geomaterials at various strain levels. Especially, a need exists to establish the pre-failure nonlinear characteristic of cemented granular geomaterials used in road constructions. In this paper, therefore, conventional granular soils were mixed with various cementing materials, such as cement and fly ash from coal combustion by-products. Then, the normalized nonlinear behavior of cemented geomaterials was assessed using unconfined compression test. In addition, various constitutive models of soils were evaluated for estimating pre-failure non-linear behavior of cemented geomaterials from the test results.

• Journal of the Korean Society for Railway
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• v.17 no.1
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• pp.43-51
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• 2014

In the earth structures of railways, large coarse granular materials are widely used as fill materials. However, experimental studies that consider the dynamic properties of these coarse granular materials have rarely been carried out in Korea due to the lack of a large scale test apparatus in this country. In this study, large scale cyclic triaxial tests were carried out for materials such as reinforced roadbed (subballast, graded crushed stone), transition zone gravel, and the upper subgrade of a railway. These specimens were prepared according to certain conditions (dry unit weight, grain size distribution, and so on) specified in the Korea railroad design standard. Based on these large triaxial test results, normalized shear modulus and damping ratio curves according to small strain level are suggested. A model and coefficients for each material are also proposed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.6
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• pp.766-771
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• 2016

The pacific oyster Crassostrea gigas has a desirable taste and flavor that differs from those of other fish and shellfish. In order to develop a high value-added product from individually quick-frozen oyster extract (IQFOE), we prepared an oyster granular flavor seasoning (OGS) from IQFOE and characterized its qualities. The OGS was prepared by granular molding and fluidized bed drying with inosine monophosphate (IMP, 0.1%), yeast extract powder (1.4%), tangle extract powder (0.6%), monosodium glutamate (MSG, 5.0%), microcrystalline cellulose (0.6%), lactose (27.5%), salt (33.0%), spray-dried IQFOE (22.5%) as a powdered materials, and IQFOE ($Brix\;25^{\circ}$, 7.0%), soy sauce (0.4%) and water (1.7%) as a liquid materials. The moisture, crude protein, pH and salinity of the OGS were 3.4%, 12.5%, 6.50 and 32.0%, respectively. Especially, the OGS revealed very higher amino-N content (1,856.0 mg/100 g) than that (1,291.2-1,610.2 mg/100 g) of other commercial flavor seasonings. In taste-active compounds, free amino acid contents was 1,359.0 mg/100 g, and major ones were glutamic acid, taurine, hydroxyproline, glycine, lysine, phosphoserine, proline in order. And OGS showed good organoleptic qualities for taste, odor and general preference compared with commercial flavor seasonings on a local market.

• Journal of the Korean Geosynthetics Society
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• v.5 no.4
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• pp.19-25
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• 2006

To examine the general features of a sand-clay composite triaxial test by making specimen varying ratios of diameters (dw) of sand columns that are installed on the soft ground as drains to diameters (de) of drain zone so called drainage space ratio (n=de/dw), densities of the granular columns, and strength of soft soils round around. I also conducted a test to research the reinforcement ability and effects of the ground when the granular columns are wrapped with supplementary materials such as geotextile. The results of the triaxial compression test showed that the shear strength increase is much big when the granular columns are wrapped with supplementary materials, while the shear strength increases as the diameter and density of the granular column increase in general. Also the drainage space ratio shows a distinct increase just below 3 and a similar shear behavior to sand is appeared. The pore water pressure coefficient decreases as the drainage space ratio decreases, however, when the drainage space ratio is less than 3~4, it declines significantly as shown in the results of shear behavior.

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.08a
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• pp.84.2-84
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• 1998

• Journal of the Korean Geotechnical Society
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• v.16 no.3
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• pp.89-89
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• 2000

The shear behavior of any interface is a function of the fundamental properties of both materials at the interface. This study aimed at investigating the effect of planar surface roughness on the stress-horizontal displacement curve at theinterfaces composed of various geomembrane textures and granular materials. In addition, the extent of surfacialscarring on smooth geomembranes against granular materials during shearing induced by plowing effect was studied. It wasobserved that the displacements required to achieve peak and residual interface resistance, and the stress-displacementcurve at the interface vary greatly with the surface roughness of geomembrane. Quantification of surface roughnessvariations on smooth geomembrane due to plowing effect showed that the surfacial scarring during shearing by the soilparticles is directly related to both the normal stress and the angularity of the soil particles at the interface. The findingsof this study can be used to provide the useful information for the design and selection of counterface materials.

• Korean Journal of Materials Research
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• v.29 no.8
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• pp.511-518
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• 2019

In this study, the effect of carbon equivalent and cooling rate on microstructure and hardness of A516 steels for pressure vessel is investigated. Six kinds of specimens are fabricated by varying carbon equivalent and cooling rate, and their microstructures and hardness levels are analyzed. Specimens with low carbon equivalent consist of ferrite and pearlite. As the cooling rate increases, the size of pearlite decreases slightly. The specimens with high carbon equivalent and rapid cooling rates of 10 and $20^{\circ}C/s$ consist of not only ferrite and pearlite but also bainite structure, such as granular bainite, acicular ferrite, and bainite ferrite. As the cooling rate increases, the volume fractions of bainite structure increase and the effective grain size decreases. The effective grain sizes of granular bainite, acicular ferrite, and bainitic ferrite are ~20, ~5, and ${\sim}10{{\mu}m$, respectively. In the specimens with bainite structure, the volume fractions of acicular ferrite and bainitic ferrite, with small effective grains, increase as cooling rate increases, and so the hardness increases significantly.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.293.2-293.2
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• 2008

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.20-20
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• 2008