• Korean Journal of Agricultural Science
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• v.51 no.2
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• pp.147-158
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• 2024

Hepatic fibrosis refers to the scarring of liver tissue, often resulting from chronic liver injury or inflammation. It is characterized by excessive deposition of extracellular matrix proteins, impairing liver function and potentially progressing to cirrhosis if left untreated. To improve the liver functions, Cordyceps militaris, a species of parasitic fungus known for its medicinal properties, is used in the form of extract. It has been traditionally used in Chinese medicine to boost energy, improve stamina, and support overall health. In this study, we investigated the hepatoprotective effects of Cordyceps militaris extract powder in a liver injury model induced by hepatic fibrosis. Sprague-Dawley (SD) rats were administered Dimethylnitrosamine (DMN) to induce liver injury, and the hepatoprotective effects of Cordyceps militaris extract powder intake were assessed by comparing changes in liver enzyme levels and histological observations. Rats injected with DMN were orally administered Cordyceps militaris extract powder at doses of 0, 125, 250, and 500 mg·kg^-1·day^-1 for three weeks. After three weeks of treatment, no significant differences were observed in hematological, clinical chemical, organ weight, gross examination, or microscopic examination between the DMN-alone group and the Cordyceps militaris extract powder-treated group. In conclusion, hepatoprotective effects against DMN-induced liver injury in SD rats treated with Cordyceps militaris extract powder were not observed under this study condition.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1155-1158
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• 2005

Micro-stereolithography is a newly proposed technology as a means that can fabricate a 3D micro structure of free form. It makes a 3D micro-structure by dividing the shape into many slices of relevant thickness along horizontal surfaces, hardening each layer of slice with a focused laser beam, and stacking them up to a desired shape. However, we do not anticipate the electric conductivity of the final product at the existing micro-stereolithography. The reason is that this technology uses polymer to make the product. Thus the new suspension which was mixed conventional photopolymer with metal powder was developed in this study. The developed suspensions were based on SL5180 which is commercialized resin and IMS03 that is made in our laboratory. And Triton X-100 was added at the suspension for getting the scattering effect and stabilizing effect. The layer recoating device was developed to be flat the mixed high viscosity suspension. A 3D micro structure was manufactured by using recoating system and micro-stereolithography system. The fabricated product was sintered to get the electric conductivity. After sintering, a pure copper product was made. In this study, new process was developed by making metal micro structure having an electric conductivity. This technology broadened the realm of the micro-stereolithography technology. And it will be applied to make the 3D micro structure of free form which has a high hardness and an electric conductivity in the near future.

• Journal of Powder Materials
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• v.23 no.3
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• pp.240-246
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• 2016

In order to improve the high-temperature oxidation stability, sintered 434L stainless steel is studied, focusing on the effect of the addition of metallic oxides to form stable oxide films on the inner particle surface. The green compacts of Fecralloy powder or amorphous silica are added on STS434L and oxidized at $950^{\circ}C$ up to 210 h. The weight change ratio of 434L with amorphous silica is higher than that of 434L mixed with Fecralloy, and the weight increase follows a parabolic law, which implies that the oxide film grows according to oxide diffusion through the densely formed oxide film. In the case of 434L mixed with Fecralloy, the elements in the matrix diffuse through the grain boundaries and form $Al_2O_3$ and Fe-Cr oxides. Stable high temperature corrosion resistance and electrical resistivity are obtained for STS434L mixed with Fecralloy.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.726-731
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• 2002

Reaction synthesis is a process to form ceramics, intermetallics and their composites from elemental powder mixture. Application of this process to a surface modification techniques has a possibilities to enable the process at a lower temperature or for a shorter time, although synthesized materials are likely to include voids and unreacted elements. This paper intend to examine the effect of Si addition to the mixture of Al and Ni on the densification of synthesized Ni-Al intermetallic compounds and to evaluate the surface properties of obtained coatings. By the Si addition, exothermic reaction temperature to form Ni-Al intermetallic was lowered to be below the melting point of Al. Si soluted $Al_3$Ni$_2$, $Al_3$Ni and $Al_{6}$Ni$_3$Si were mainly formed in the coating layer when powder mixture was heated to 973K for 300s. Besides, densification was enhanced by increasing hot press pressure, Si additions and heating rate. When the composition of eutectic Al-Si reaches 78%, void ratio of sintered compact reduced to 0.4%. It is caused by higher flowability of Al-Si liquid phase generated and its infiltration into the void. Since the hardness of NiAl(Si) compound (about 600HV) formed in the coating layer is higher than that of Ni-Al compound (about 400HV), coating layer with high density and superior wear property is obtained by hot press using reaction synthesis from Al-Ni-Si powder mixture.

• Analytical Science and Technology
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• v.20 no.4
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• pp.302-307
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• 2007

The reaction morphology was investigated depending on the amounts of HCl and $NH_4OH$, and the effect of pH was studied on the preparation of $TiO_2$ nanopowders. $TiO_2$ nanopowder was prepared using a titanium tetra-isopropoxide. Subsequently, the effect of pH on the characteristics of the prepared $TiO_2$ nanopowder was evaluated depending on the amounts of the catalysts such as HCl and $NH_4OH$. The morphology and phase transformation of $TiO_2$ powder prepared by hydrolysis of titanium tetra-isopropoxide were strongly influenced by the presence of the catalysts. In the case of using $NH_4OH$, the morphology of the $TiO_2$ powder exhibited powder form. For the HCl catalyst, it showed bulk or granule form. The phase transformations of amorphous $Ti(OH)_4$ to anatase $TiO_2$ and the anatase to rutile was significantly influenced by the kind and amount of thecatalysts.

• Journal of the Korean Ceramic Society
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• v.25 no.2
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• pp.111-116
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• 1988

Aluminum hydrates were prepared by precipitation method using Al2(SO4)3$.$18H2O as a starting material and NH4OH as precipitation agent. The phases of aluminum hydrate were changed from amorphous aluminum hydrate to pseudo-boehmite of AlOOH form and bayerite, gibbsite, hydragillite and norstrandite of Al(OH)3 form with increasing pH. As pH increased, agglomeration phenomena were reduced. Aluminum hydrates of AlOOH and Al(OH)3 form represented dehydration of structural water near 175$^{\circ}C$ and 385$^{\circ}C$, and 280$^{\circ}C$, respectively. As the ratio of Al(OH)3 to AlOOH increased, specific surface area was reduced.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.483-487
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• 2001

As a part of basic investigation for utilizing of cuttle bone as a calcium source, we examined on the extraction methods (calcining at $800^{\circ}C$ for 2 hrs, autoclaving at $121^{\circ}C$ for 10 hrs and ultrasonic treatments at $60^{\circ}C$ for 10 hrs) as a pretreatment methods for preparation of calcium-based powder from cuttle bone, The color of calcined calcium-based powder from cuttle bone was white, while that treated by other methods was light yellow. The calcium content in calcined calcium-based powder was $70.5\%$, and revealed high about 2 times compared to those pretreated by other methods. And, calcium solubility in calcined calcium-based powder was improved 22 times compared to raw cuttle bone powder, Among calcining, autoclaving and ultrasonic treatments as a pretreaoent methods for preparation of calcium-based powder from cuttle bone, calcining treatment was superior to other methods on the aspect of color, calcium solubility and purity of calcium-based powder, Judging from X-ray diffraction pattern of calcined calcium-based powder, most of calcium was present as a form of calcium oxide, But, pH of calcined calcium-based powder revealed strong alkali of pH 12.9. This pH value might invoke health risk in using food resource. Therefore, for utilization effectively calcined calcium-based powder from cuttle bone, it requires a suitable treatment such as adjustment of pH to neutral condition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.2
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• pp.136-140
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• 2002

The investment casting process is used frequently to manufacture precise and complex shape metal parts. The previous wax pattern manufacturing process takes long time and high costs because the process is performed by hands. In order to improve the wax manufacturing process, a new process is developed to manufacture the wax pattern by using a rapid prototyping system. A CastForm pattern is made by a Selective laser Sintering type RP with CastForm powder. The CastForm pattern is dipped in the melted wax liquid, and the melted wax penetrates into the pores of the CastForm pattern. Wax pattern is obtained after cooling the CastForm pattern slowly. A stainless steel part has been manufactured by the suggested process. By obtaining the suggested process the manufacturing time and costs are reduced largely and the accuracy is improved.

• Korean Journal of Materials Research
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• v.8 no.3
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• pp.206-213
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• 1998

Cu, Ni, and Mo were ion-diffused into the pure steel powder in the aqueous solution of $(CuNO_3)_2$, $Ni(NO_3)_2)_2$, and $(NH_4)_6Mo_7O_{24}$, to form partial diffusion bond prealloyed steel powder. The mechanical properties, and compacting and sintering characteristics were investigated as a function of Cu. Ni and Mo contents. The results of the this research, it was found that the smallest change of size was observed, and the good degree of hardness and tensile strength was observed when 1.50wt%Cu, 1.75wt%Ni and 0.50wt%Mo was added each other. The powder metallurgy characteristics of partial diffusion bond prealloyed steel powder containing 1.50wt% of Cu, 1.75wt% of Ni and 0.5wt% of Mo were compared to those of distalloy $AB\textregistered$ which was manufactured in Hogani Corporation of Sweden. Partial diffusion bond prealloyed steel powder of this study had good degree of hardness and density, and its dimensional stability was same to that of pure steel powder. Under the same sintering density and temperature, the tensile strength of the ion powder from this research was $15~20Kg/\textrm{mm}^2$ larger than that of distalloy AB'. also the hardness was larger in the magnitude of Hv20-30. When the powder metallurgy heat-treated, hardness and tensile strength were substantially increased.

• Journal of Animal Science and Technology
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• v.50 no.2
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• pp.217-226
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• 2008

Product quality of low-fat sausages(LFSs) manufactured with two types(powder and hydrated) and two levels(0.5 and 1.0%) of Acorn powder was evaluated as a potential fat replacer. The addition of Acorn powder did not affect the product quality of LFSs (P>0.05), however 0.5% and hydrated Acorn was better sensory flavor than 1.0% and powder counterparts. The addition of Acorn into the LFSs decreased the expressible moisture(%) except for 0.5% powder type and decreased Hunter L-values in LFSs. The addition of 1.0% hydrated Acorn lowered sensory saltiness than those of other LFSs and regular-fat control. These results indicated that Acorn powder can be used to manufacture LFSs as a fat replacer and 0.5% with hydrated form had better characteristics than 1.0% and powder counterparts. Future research will be performed to prevent the color change with the addition of Arcon powder in LFSs.