• Ecology and Resilient Infrastructure
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• v.6 no.4
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• pp.179-190
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• 2019

In this study, a fish survey was conducted to investigate the habitat status of black shinner (Pseudopungtungia nigra) designated as endangered species level from the lower part of Yongdam Dam to the upper part of Daecheong Dam. Biodiversity analysis was performed on the basis of the number of fish emerged, and biological health and physical habitat environment were quantitatively analyzed using collected P. nigra. According to the survey, the habitat range of P. nigra was found from Banguri-myeon, Buri-myeon, Geumsan-gun, downstream of Yongdam Dam. The biodiversity analysis results of all species appeared to be low in overall dominance index and relatively high in species diversity and uniformity index. In addition, P. nigra collected in this study was confirmed to have normal growth and nutritional status by the full-length-weighted relativities and condition factor. The physical habitat environment of P. nigra was 0.3 - 0.6 m in depth, 0.3 - 0.7 m/s in flow rate, and bed materials showed high frequency of occurrence in the range of cobbles (64.0 - 256.0 mm) to boulders (>256.0 mm). These results are expected to be used as data for habitat restoration and management in the future as basic data on the spatial range and preferred physical habitat environment of P. nigra in Geumgang.

• Archives of design research
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• v.17 no.4
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• pp.211-222
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• 2004

During the 1980s, Textile design achieved a remarkable growth in creating aesthetic effect and in establishing its standing by responding to demands of the time effectively and seeking changes proactively. This was a period when Textile design constructed its modern concept as it was attempting a qualitative improvement through advanced technology, high class, and differentiation. The advent of advanced materials through the development of textile engineering, employment of craft techniques to further cultural and artistic orientation, and restoration of decorativeness in pursuit of sensitivity, all these developments of the 1980s contributed to the rise of above characteristics. In this study, attempts are made to grasp the new trend of Textile design during the 1980s and to review diverse methods of aesthetic creation and plastic possibility which this trend presented for the Textile, and thus to recognize the role of Textile design and its importance in a new light. The new trend of Textile design during the 1980s can be summarized as follows: 1) An appreciation of the creative aspect of the Textile. As attempts are made to emphasize visual and sensitive aspects of the medium, Textile tended to become an object of art itself. 2) A new awareness of the representative and plastic capacity of the fiber material. As attempts are made to develope the creative potential of the Textile, representation of the material tended to become more diversified. 3) A recognition of the Textile as a proper means to deliver the spirit of the time. As the medium accommodates and fuses diverse cultures including traditional culture, more emphasis was place on cultural contents of the Textile. In the process of pursuing these changes, Textile design of the 1980s has also contributed to the creation of new values, laying the groundwork for its emergence as an advanced high value-added industry.

• Journal of Korea Foundry Society
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• v.38 no.6
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• pp.111-120
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• 2018

In this study, the effects of two different casting methods (gravity casting and, diecasting) and various solid-solution conditions on the mechanical properties of ASC (Al-10.5wt%Si-1.75wt%Cu) and ALDC12 (Al-10.3wt%Si-1.72wt%Cu-0.76wt%Fe-0.28wt% Mn-0.32wt%Mg-0.9wt%Zn) alloys were investigated. A thermodynamic solidification analysis program (PANDAT) was used to predict the liquidus, solidus, and phases of the used alloys. In the results of an XRD analysis, ${\beta}$-AlFeSi peaks were observed only in the ALDC12 alloy regardless of the casting method or SST (solid-solution treatment) conditions. However, according to the results of a FE-SEM observation, both ${\theta}(Al_2Cu)$ and ${\beta}$-AlFeSi were found to exist besides ${\alpha}$-Al and eutectic Si in the gravity-casted ASC alloy at $500^{\circ}C$ after a SST of 120min. The ${\alpha}$-AlFeSi and ${\beta}$-AlFeSi phases including the eutectic phases were also found to exist in the ALDC12 alloy. The results of a microstructural observation and analyses by XRD, FE-SEM and EDS were in good agreement with the PANDAT results. The gravity-casted ALDC12 and ASC specimens showed the highest Y.S. and UTS values after aging for three hours at $180^{\circ}C$ after a SST at $500^{\circ}C$ for 30min. At longer solid-solution treatment times at $500^{\circ}C$ in the gravity-casted ALDC12 and ASC specimens, the elongations of the ASC alloys increased, whereas they decreased slightly in the ALDC12 alloys.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.4
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• pp.293-298
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• 2010

Purpose: The objective of the present study was to determine the capability of electrospun silk fibroin as a biomaterial template for bone formation when mixed with nano-hydoxyapatite in vivo. Materials and Methods: Ten New Zealand white rabbits were used for this study and bilateral round shaped defects were formed in the parietal bone (diameter: 8.0 mm). The electrospun silk fibroin was coated by nano-hydroxyapatite and grafted into the right parietal bone (experimental group). The left side (control group) did not receive a graft. The animals were sacrificed at 6 weeks and 12 weeks, humanly. The microcomputerized tomogram (${\mu}CT$) was taken for each specimen. Subsequently, they were undergone decalcification and stained for the histological analysis. Results: The average value of all measured variables was higher in the experimental group than in the control at 6 weeks after the operation. BMC in the experimental group at 6 weeks after operation was $48.94{\pm}19.25$ and that in the control was $26.17{\pm}16.40$ (P = 0.027). BMD in the experimental group at 6 weeks after operation was $324.59{\pm}165.24$ and that in the control was $173.03{\pm}120.30$ (P = 0.044). TMC in the experimental group at 6 weeks after operation was $19.50{\pm}6.00$ and that in the control was $10.52{\pm}6.20$ (P = 0.011). TMD in the experimental group at 6 weeks after operation was $508.88{\pm}297.57$ and that in the control was $273.54{\pm}175.91$ (P = 0.06). Gross image of both groups showed higher calcification area at 12 weeks than them in 6 weeks. The average value of ${\mu}CT$ analysis was higher at 12 weeks than that in 6 weeks in both groups. BMC in the experimental group at 12 weeks after operation was $51.21{\pm}8.81$ and that in the control was $33.47{\pm}11.13$ (P = 0.010). BMD in the experimental group at 12 weeks after operation was $323.39{\pm}21.54$ and that in the control was $197.75{\pm}76.23$ (P = 0.012). TMC in the experimental group at 12 weeks after operation was $21.44{\pm}5.30$ and that in the control was $13.31{\pm}4.17$ (P = 0.008). TMD in the experimental group at 12 weeks after operation was $524.47{\pm}19.37$ and that in the control was $299.60{\pm}136.20$ (P = 0.016). Conclusion: The rabbit calvarial defect could be successfully repaired by electrospun silk nano-fiber combined with nano-hydroxyapatite.

• Journal of Radiation Protection and Research
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• v.41 no.1
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• pp.49-55
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• 2016

Background: For the purpose of baseline data collection and enhancement of environmental monitoring the distribution studies of $^{137}Cs$ and $^{90}Sr$ in the soil of Uljin province was performed and the relation between surface soil activities and soil properties (pH, TOC and median of the surface soil) was analyzed. Materials and Methods: For 14 spots within 10 km from the NPP surface soil samples were collected and soils for depth profile were sampled for 3 spots in April 2011. Using ${\gamma}$-ray spectrometry with HPGe detector, the concentrations of $^{137}Cs$ were determined and the concentrations of $^{90}Sr$ were measured by counting ${\beta}$-activity of $^{90}Y$ (in equilibrium with $^{90}Sr$) in a gas flow proportional counter. Results and Discussion: The concentration ranges of $^{137}Cs$ and $^{90}Sr$ were $<0.479-39.6Bq{\cdot}(kg-dry)^{-1}$ (avg. $7.51Bq{\cdot}(kg-dry)^{-1}$) and $0.209-1.85Bq{\cdot}(kg-dry)^{-1}$ (avg. $0.74Bq{\cdot}(kg-dry)^{-1}$) which were similar to the reported values from other regions in Korea. The activity ratio of $^{137}Cs$ to $^{90}Sr$ in surface soils was around 9.67, which is much bigger than the initial value of 1.75 for worldwide fallouts because of faster downward movement of $^{90}Sr$ after fallout than that of $^{137}Cs$. For depth profile studies soils were collected down to 40 cm depth for the locations of Deokgu, Hujeong and Maehwa. The $^{137}Cs$ concentration distribution of the first two showed maximum values at top soils and decreased rapidly in exponential manner, while $^{90}Sr$ showed two local maximum values for soils near top and about 30 cm depth. Through linear fittings between the $^{137}Cs$ and $^{90}Sr$ concentrations of surface soil and pH, TOC and median of the surface soil, the only probable relationship obtained was between $^{137}Cs$ and TOC (determination coefficient $R^2=0.6$). Conclusion: The concentration ranges of $^{137}Cs$ and $^{90}Sr$ in Uljin were similar to the reported values from other regions in Korea. The only probable relationship obtained between activities and soil properties was between $^{137}Cs$ and TOC.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.2
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• pp.92-97
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• 2011

Landfill is the main treatment method for bottom-ash because it has not only an irregular particle size and ingredients but also not proper recycling treatment. The aim of this study is to raise recycling rate of bottom-ash(nonplasticity pulverulent) and for the purpose of alternatives of clay to investigate the properties of Bottom-ash (B/A)-Hard Clay (H/C) bodies with controlled interfacial chemistry properties. After investigating the sedimentation height of suspensions with controlled pH, it was discovered that there was no hetero-polar aggregation for mixed slips because hard clay and bottom-ash had similar interfacial chemistry properties. Also, bulk density, water absorption, and microstructure properties of each pellet was observed that made by silp casting method and manufactured at $50^{\circ}C$ intervals between $1000{\sim}1250^{\circ}C$. As a result, dispersed slip of clay and bottom ash are possible for slip casting and plastic forming process because they exhibit Bingham plastic behavior. Products that made by slip with dispersed clay and bottom ash are not only suitable for KS L 4201 and KS L 1001 at $1250^{\circ}C$ but it is also possible to apply for ceramic and sanitary ware because specific gravity was about 15 % lighter than general ceramic materials.

• Journal of Dental Rehabilitation and Applied Science
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• v.20 no.2
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• pp.109-120
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• 2004

INTRODUCTION: The build-up method has been used for application of porcelain powder on the metal framework to make final tooth shape conventionally. This method takes time and need skill to mimic final shade and shape of porcelain fused to metal crown. The purpose of this study was to develop standard shape and shade laminating porcelain forms to reduce build-up time. METHODS: To make tooth form porcelain paste, several liquid organic compounds were added to conventional feldspathic porcelain. The amount of additives and rheologic property were tested to find out best composition. Comparison of mixing methods to reduced porosity, proper heating schedule, and measurement of shrinkage amount and residual organic materials were performed to set-up standard procedures. Finally, biaxial flexural strength and color of preformed laminated paste porcelain were compared with those of porcelain which fabricated by the conventional build-up method. RESULTS: There was no significant difference in physical properties and color stability between two fabrication methods after various testing methods. Conclusion: This new build-up method can be applied to fabricate the PFM crown and bridge without any loss of strength and optical properties.

• The Journal of the Korean bone and joint tumor society
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• v.15 no.2
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• pp.130-137
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• 2009

Purpose: STAT3 is an oncogene that regulates critical cellular processes, and its constitutive activation has been demonstrated to correlate with biological and clinical features in many types of human malignancy. Materials and Methods: In this study, STAT3 activation was assessed in variable benign and malignant chondroid tumors in bone by immunohistochemistry using a monoclonal antibody specific for $tyrosine^{705}$-phosphorylated STAT3 ($pSTAT3^{tyr705}$). Results: Among conventional chondrosarcomas (n=17), three cases(50%) of grade III chondrosarcomas were pSTAT3-positive. All grade I and II chondrosarcomas were pSTAT3-negative. This pSTAT3 positivity according to the histologic grade was statistically significant (p=0.0432). Two cases(50%) of clear cell chondrosarcomas were pSTAT3-positive. Six cases (50%) among 12 benign chondroid tumors(6 enchondromas, 3 chondroblastomas, and 3 chondromyxoid fibromas) were also $pSTAT3^{tyr705}$-positive. Conclusion: In conclusion, STAT3 activation is associated with higher tumor grade in conventional chondrosarcomas. Our results suggest that STAT3 is activated in a subset of benign and malignant chondroid tumors, and may support the extension of the cancer stem cell hypothesis to include tumors of cartilaginous lineage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.3108-3113
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• 2013

Compatibility between mLLDPE and HDPE was investigated by observing the crystallization behavior and mechanical properties of their blends. HDPE and mLLDPE blends were prepared by a melt-blending with compositions of 100/0, 80/20, 60/40, 40/60/ 20/80 and 0/100. Four different mLLDPEs containing various octene contents (4.1, 6.8, 9.8 및 12.5 mol.%) were investigated. The melting temperature and crystallization peak temperature of the blends were measured by DSC and the mechanical properties were measured in an universal testing machine. By observation that the melting and crystallization peak temperatures of one component were affected by its counterparts, it was revealed that HDPE and mLLDPE are miscible or at leat partially miscible at molten state. It was also found that the crystalline phase of mLLDPE contains HDPE crystals. However. it was not clear that mLLDPE was cocrystalized in the crystalline phase of HDPE. By various investigation with DSC and mechanical properties, it was concluded that the compatibility between mLLDPE and HDPE decreases with the octene content in the mLLDPE.

• Journal of the Korean Vacuum Society
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• v.22 no.4
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• pp.181-187
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• 2013

$Dy^{3+}$-doped $BaMoO_4$ phosphor powders were synthesized by using the solid-state reaction method and their crystalline structure, morphology and size of particles, excitation and emission properties were investigated. The structure of all the phosphor powders, irrespective of the mol ratio of $Dy^{3+}$ ions, was found to be the tetragonal system with the main diffraction peak at (112) plane. The grain particles agglomerate together to form larger clusters with increasing the mol ratio of $Dy^{3+}$ ions. The excitation spectra were composed of a broad band centered at 293 nm and weak multiline peaked in the range of 230~320 nm, which were due to the transitions of $Dy^{3+}$ ions. The emission of the phosphors peaking at 666 and 754 nm, originating from the transitions of $^4F_{9/2}{\rightarrow}^6H_{11/2}$ and $^4F_{9/2}{\rightarrow}^6H_{9/2}$ of $Dy^{3+}$ ions, was rather weak, while the intensity of blue and yellow emission peaking at 486 nm and 577 nm due to the transitions of $^4F_{9/2}{\rightarrow}^6H_{15/2}$ and $^4F_{9/2}{\rightarrow}^6H_{13/2}$ of $Dy^{3+}$ ions was significantly stronger. The experimental results suggest that the white-light emission can be realized by controlling the yellow-to-blue intensity ratio of $Dy^{3+}$ emission.