• Journal of the Mineralogical Society of Korea
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• v.17 no.4
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• pp.357-364
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• 2004

Mineral chemistry of talc from the Dongyang talc deposits was studied to characterize the differences between dolomite-origin talc (talc I) and tremolite-origin talc (talc II). Average iron and aluminum contents are higher in talc II, 2.18 wt% FeO and 0.31 wt% $Al_2$O$_3$), than in talc I, 1.48 wt% FeO and 0.08 wt% $Al_2$O$_3$). Consistently lower Mg/(Mg+Fe+Mn) ratios and higher AI concentrations with uniform values of talc II compared to talc I seem to reflect the compositional differences of the original materials, tremolite and dolomite, respectively. Relative enrichment of Al as well as Fe in talc II compared to tremolite can be attributed to their immobile behaviors during alteration process and the rapid diffusion of hydrothermal fluids, which can accelerate instantaneous nucleation with immaturity growth of talc II. Increase in the concentrations of talc II can lower the ore grade by increasing concentrations of impure components such as AI and Fe, and by abundant presence of tremolite as well.

• Magazine of the Korea Concrete Institute
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• v.8 no.6
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• pp.235-243
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• 1996

The mechanical behavior ot concrete is strongly influenced by various scenarios of crack initiation and crack propagation. Recently. the study of the interface fracture and cracking in interfacial regions is emerged as an important field, in the context of the developement of high performance concrete composites. The crack path criterion for elastically homogeneous materials is not valid when the crack advances at an interface because. in this case, the consideration of the relative magnitudes of the fracture toughnesses between the constituent materials and the interface are involved. In this paper, a numerical method is presented to obtain the values of two interfacial fracture parameters such as the energy release rate and the phase angle at the tip of an existing interface crack. Criteria based on energy release rate concepts are suggested for the prediction of crack growth at the interfaces and an hybrid experimental-numerical study is presented on the two-phase beam composite models containing interface cracks to investigate the cracking scenarios in interfacial regions. In general, good agreement between the experimental results and the prediction from the criteria is obtained.

• Journal of the Korean Ceramic Society
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• v.43 no.11 s.294
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• pp.715-723
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• 2006

Perovskite oxide materials are very important for the electronics industry, because they exhibit promising properties. With an interest in the obvious applications, significant effort has been invested in the growth of highly crystalline epitaxial perovskite oxide thin films in our laboratory. And the desired structure of films was formed to achieve excellent properties. $Y_1Ba_2Cu_3O_{7-x}$ (YBCO) superconducting thin films were simultaneously deposited on both sides of 3 inch wafer by inverted cylindrical sputtering. Values of microwave surface resistance R$_2$ (75 K, 145 GHz, 0 T) smaller than 100 m$\Omega$ were reached over the whole area of YBCO thin films by pre-seeded a self-template layer. For implementation of voltage tunable high-quality varactor, A tri-layer structured SrTiO$_3$ (STO) thin films with different tetragonal distortion degree was prepared in order to simultaneously achieve a large relative capacitance change and a small dielectric loss. Highly a-axis textured $Ba_{0.65}Sr_{0.35}TiO_3$ (BST65/35) thin films was grown on Pt/Ti/SiO$_2$/Si substrate for monolithic bolometers by introducing $Ba_{0.65}Sr_{0.35}RuO_3$ (BSR65/35) thin films as buffer layer. With the buffer layer, the leakage current density of BST65/35 thin films were greatly reduced, and the pyroelectric coefficient of $7.6\times10_{-7}$ C $cm^{-2}$ $K^{-1}$ was achieved at 6 V/$\mu$m bias and room temperature.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.8
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• pp.75-81
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• 2008

Water treatment study employing plasma is thoroughly examined in the following paper. The research using water plasma torch showed superior results in terms of economical and energy efficiency due to the substantial reduction of electric power. A comparison of streamer and arc discharge phenomena taken place in water was put under close scrutiny. Dyeing wastewater exposed to the plasma treatment was sampled and analyzed for relative dissolved ozone concentration, hydrogen peroxide, as well as the color removal efficiency. It was found that streamer discharges is more effective than arc discharge in growth of $H_2O_2$ and $O_3$ by plasma chemical constituents, though plasma torch had small oxidation reagents selectivity. Thus, streamer discharges, due to the efficient plasma-chemical reactions environment, proved to be more efficient compare to the thermal arc plasma loading.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• no.1
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• pp.13-25
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• 2001

Recently there have been increasing demands and desire for the urban open space due to urban development or environmental deterioration. Urban natural parks in Seoul provide citizens with comfortable open space and thus play an important role as learning spaces to experience nature and understand the environment. Accordingly, this study aims to analyze existing vegetation and provide basic data for the conservation and management plans of urban natural parks and education programs. The contents of the study encompass natural environment such as topography, altitude, slope and aspect and botanical ecosystem including the structure of plant communities and tree growth. According to the result of topography analysis, the overall altitude was not high but the slope was relative steep. Vegetation of Seoo Royal Tomb, a urban natural park has been classified into 12 types, and they include; Quercus acutissima community(lowland type), Quercus acutissima community(valley type), quercus variabilis community, Quercus mongolica community, Castanea crenata community, Capinus laxiflora community, Pinus densiflora community(lowland type), Pinus densiflora community(slope type), Robinia pseudo-acacia community, Populos$\times$albaglandulosa community, Pinus rigida community, and Pinus koraiensis community. Based on the survey and analysis results, we have classified the study area into conservation, buffer, and utilization zones for the effective management. This study provides basic data to support the establishment of master plans for urban natural parks by analyzing vegetation conditions at Seoo Royal Tomb, an urban natural park, Based on the results presented in the study, consistent monitoring work needs to be conducted, and elaborate management plans also should be prepared.

• Environmental and Resource Economics Review
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• v.28 no.4
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• pp.583-615
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• 2019

This paper investigates the level of decoupling between greenhouse gas emissions and economic growth in Korea. Despite previous studies mainly stressed the existence of the Environmental Kuznets Curve, the lack of investigations in the level of decoupling constraints further policy suggestions. This study analyzes the level of decoupling in the short- and long-term, focusing on short-term volatility of GHG emissions income elasticity. In the long run, there is no decoupling in Korea because a robust causal relationship exists between GHGs, GDP, and fossil fuels. However, the short-term volatility is clearly identified under the long-term equilibrium(coupling), indicating there is the relative decoupling in the short run. The results show that fossil fuel dependence is a significant factor that increases short-term volatility(decoupling) and breaks the causal link(coupling) between GHGs and GDP.

• Journal of Conservation Science
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• v.6 no.2 s.8
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• pp.141-148
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• 1997

When we have entered high economic growth since 1970s, many archaeological excavations were performed all over the country. Excavated objects composed of variable materials are inevitably subjected to deformations owing to surrounding environments and storage conditions. Although the importance of conservation treatment of the objects is greatly increased, a few conservation laboratories are there comparing with excavation groups. The metallic objects excavated are very unstable and deformable state. So it is important not to allow iron objects, especially cast iron, to dry out once excavated. Because the corrosion reactions on the surface proceed rapidly, the objects may be destroyed at the moment. The conservation procedures of the excavated metallic objects are as follows: (1)It is stable on-site storage method for objects to keep vinyl film with envelop or to immerse alkaline solution to prevent the environmental changes. (2)The objects must be treated at once under suitable methods in the conservation laboratory after excavation. (3)The continued existence of objects depends on environmental factors such as relative humidities, regular inspection, light etc.

• Journal of the Korean Society of Clothing and Textiles
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• v.15 no.4 s.40
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• pp.341-349
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• 1991

This study was done to provide basic data for clothing design and thus to contribute to the academic development of the clothing and textile area. The focus of this study was to charac­terize the somatotype based on each individual's lateral view. For this purpose, firstly, categorization of the subjects based on their lateral view and definition of each category, secondly, characterization of each somatotype, and thirdly, sugges­tion of the deterministic criteria of each category were complished. The subjects in this study were female college students of 18 to 26 year-old whose somatotypes were comparatively invariable after cessation of physical growth. The metrical items characterizing upper body lateral view were chosen. Data were collected through Anthropometry and Photometry and analyzed by Factor analysis. The results were as follows; 1. Each subject's side view contour was classified as straight type, lean-back type, bend­forward type, and swayback according to its position to the relative plumb line. Straight type was defined as the type in which the plumb line passes through the lobe of the ear, the shoulder joint, and the mid abdominal region laterally. Lean-back type positioned the plumb line more posteriorly than straight type. Bend-forward type positioned the plumb line more anteriorly than straight type. Swayback positioned the plumb line at about the same line as straight type. And curvature of side view contur was more prominent in this type than in straight type. 2. Seven factors were figured out. The first factor was representing upperbody volume, and the second factor was representing size, the third factor was horizontal distance from lateral view representing size view contour. The fourth factor was front body length, the fifth factor was back body length. The sixth factor was shoulder length and shoulder width representing shoulder shape. The seventh factor was the bust shape.

• Journal of Microbiology and Biotechnology
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• v.24 no.3
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• pp.408-420
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• 2014

Yeast surface-displayed antibody libraries provide an efficient and quantitative screening resource for given antigens, but suffer from typically modest library sizes owing to low yeast transformation efficiency. Yeast mating is an attractive method for overcoming the limit of yeast transformation to construct a large, combinatorial antibody library, but the optimal conditions have not been reported. Here, we report a large synthetic human Fab (antigen binding fragment) yeast surface-displayed library generated by stepwise optimization of yeast mating conditions. We first constructed HC (heavy chain) and LC (light chain) libraries, where all of the six CDRs (complementarity-determining regions) of the variable domains were diversified mimicking the human germline antibody repertoires by degenerate codons, onto single frameworks of VH3-23 and $V{\kappa}1$-16 germline sequences, in two haploid cells of opposite mating types. Yeast mating conditions were optimized in the order of cell density, media pH, and cell growth phase, yielding a mating efficiency of ~58% between the two haploid cells carrying HC and LC libraries. We constructed two combinatorial Fab libraries with CDR-H3 of 9 or 11 residues in length with colony diversities of more than $10^9$ by one round of yeast mating between the two haploid HC and LC libraries, with modest diversity sizes of ${\sim}10^7$. The synthetic human Fab yeast-displayed libraries exhibited relative amino acid compositions in each position of the six CDRs that were very similar to those of the designed repertoires, suggesting that they are a promising source for human Fab antibody screening.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5795-5801
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• 2015

The low temperature distribution of the refrigerated and frozen food has been increased gradually. Refrigeration industry is using R134a refrigerant, which GWP is 1300. R1234yf is an alternative refrigerant of R134a because GWP of R1234yf refrigerant is just 4. Evaporator used in refrigeration truck refrigeration system is operated on low temperature condition. Accordingly, evaporator is formed frost and the formation of frost is rapidly decreased performance of evaporator. In this study, the performance of evaporator using R134a and R1234yf refrigerant was analyzed with operating conditions under frost condition. As a result, the performance of R134a evaporator according to air inlet temperature, relative humidity and evaporating temperature was more sensitive than R1234yf evaporator. Besides, the frost growth of R134a evaporator is steeper than that of R1234yf one.