• Title/Summary/Keyword: compositional characteristics

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Consolidation of Cu-based amorphous particles (Cu계 비정질 입자의 가압 성형)

  • Kang E. Y.;Chung Y. H.;Yoo H. G.;Park J. W.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2005.10a
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    • pp.273-276
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    • 2005
  • Packing characteristics of amorphous alloy particles were investigated by scanning electron microscopy, compositional analysis, micro-hardness test and finite element method (FEM). Electroless Ni-plating was made on the surface of the Cu-based amorphous particles before consolidation in ambient atmosphere at an intermediate region of glass transition and crystallization temperatures $(T_g\;and\;T_x)$. Some parts of the Ni-layer in the interfaces of the consolidated particles disappeared, while some of them still remained without appreciable change in compositions. No cracks or fractures were found in the particles, which may occur at low temperatures below or near $T_g$ as anticipated by the FEM analysis. Crystallization and change in hardness were not observed after consolidation.

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Occurrence of Electrum from the Namseong Gold Mine (남성(南星) 금광산산(金鑛山産) 에렉트럼의 산상(産狀))

  • Lee, Hyun Koo;Kim, Sang Jung;Choi, Seon Gyu
    • Economic and Environmental Geology
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    • v.20 no.4
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    • pp.223-234
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    • 1987
  • This paper describes the mode of occurrence and mineralogical properties of electrum from the Namseong Gold-Silver deposits, for the purpose of obtaining data on the characteristics of the ore deposits and the behavior of gold and silver during the mineralization. The gangue minerals are quartz, calcite, fluorite. Ore minerals are mainly composed of pyrite, sphalerite, chalcopyrite and galena with minor amount of argentite, electrum, pyrargyrite, native silver and unidenfied mineral(Cu-Fe-Ag-S series). Three stage of mineralization recognized are, from early to later, (I) pyrite-electrum stage (II) sphalerite-chalcopyrite-galena-argentite-electrum stage (III) sulfosalts stage. The filling temperature of fluid inclusions in quartz ranges from $225^{\circ}$ to $335^{\circ}C$. The value of sulfur fugacity estimated by means of electrum-tarnish method ranges from $10^{-11.5}$ to $10^{-14}$ atm. The compositional heterogeneity within a single grain with respect to gold concentration is common in the Namseong electrums Chemical composition of electrum ranges generally between 25~45 atom% Au. Its gold content decreases in late stages of mineralization.

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Effect of Gas Compositions on Fuel Economy and Exhaust Emissions of Natural Gas Vehicles (연료의 조성변화가 천연가스차량의 연비 및 배출가스 특성에 미치는 영향)

  • 이영재;김강출
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.8
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    • pp.123-131
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    • 1999
  • Natural gas is one of the most promising alternative fuels for automotive vehicles. However, natural gas varies in compositional between the originating fields and may be further modified due to processing and additional mixing. These variations are known to affect engine performance and emissions through changes in fuel metering and combustion characteristics. In the present study, the effect of gas compositions on vehicle performance such as fuel economy, driveability and exhaust emissions was examined. Analysis are made of using 3 types of NGVs which were made by automakers and 6 different fuels which are selected in consideration of the variation in fuel composition on the worldwide market. The results may be utilized to develop natural gas natural gas engine in automaekrs and/or to establish the fuel standard in the refueling stations.

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A Study on the Plasticity Enhancement of Coal Fry Ash-Clay Bodies (석탄회-점토계 소지의 가소성 증진에 관한 연구)

  • 이기강;이효진;박천주;김동원;김유택;김석범
    • Journal of the Korean Ceramic Society
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    • v.33 no.2
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    • pp.135-142
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    • 1996
  • Fly Ashes which are produced from coal-fired powder plants and classified as general waste can be used as raw materials for bricks and tiles because of their compositional similarity with clays. There was a limit of substituting fly ash for clay because plasticity decreased with increasing fly ash additions. Accordingly this study tried to suggest a feastibility of enhancing the substitution ratio by controlling the interfacial properties of fly ash. The slip with 1:1 volume ratio showed that best dispersive characteristics under the condition of pH 2 Filter pressed cakes made of pH 2 slips also showed better plastickity than those of untreated ones. of pH 2 Filter pressed cakes made of pH 2 also shwoed better plasticity than those of untreated ones.

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Pervaporation Process for Water/Ethanol Mixture through IPN Membranes

  • Jeon, Eun-Jin;Kim, Sung-Chul
    • Proceedings of the Membrane Society of Korea Conference
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    • 1993.04a
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    • pp.52-53
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    • 1993
  • The pervaporation behavior of EtOH/Water mixture through IPN membranes was predicted in this study. The pervaporation characteristics of single polymer membrane were modeled according to the "six-coefficients model" proposed by Brun. In the case of the IPN membrane, two models were proposed according to the phase structure of the IPN. For a uniphase membrane with no phase separation, the compositional average of the single polymer membrane was used. in the case of the phase separated IPN's two cases existed. The first was the island and sea model: in which one phase was continuous and the other was dispersed. The second was the co-continuous model where two continuous phases existed. For these cases, the permeation rate and the separation factor of the IPN membrane were calculated using the experimental sorption data and the cornponent polymer properties. Comparison with the experimental data indicated that these models could be used to predict the performances of IPN membranes depending on the morphology of the IPN.

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The Effects of Sequence on the Image of Environment - Focused on the Theory of Method - (시각적 국면이 환경 이미지에 미치는 영향 - 방법론을 중심으로 -)

  • 양세은
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2001.05a
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    • pp.90-94
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    • 2001
  • This study hypothesizes that the imageability of a particular environments is decided by the unity of each visual sequences. We selected Ch'angdok Palace as our subject due to its greater applicability for image construction among various Korean architectures and their street furnitures. we apply the analytical methods of formal aesthetics and symbolic aesthetics to Ch'angdok Palace's space compositional characteristics, we can find distinctive features. The conclusions are that Ch'angdok Palace contains high probability of imageability through the contrast and harmony of two themes, reality and the ideal, and the rational and the emotional.

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A Study on the Characteristics of Psychological Healing in the Waterscape Design of Contemporary Architecture (현대건축의 수공간 디자인에서의 심리 치유적 특성에 관한 연구)

  • Seo, Ji-Won;Kim, Kwang-Ho
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.15 no.2
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    • pp.31-38
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    • 2009
  • The purpose of this study is to research the fundamental cause of psychological stress and healing elements related to the waterscape design of contemporary architecture. As one of the solution, analysis of the psychological function of waterscape of natural elements in composition of architectural space was included. This study is focused on the form and psychological function of waterscape, and concerned with the cause of psychological stress at the same time. Also, this study includes analyzed cased with both inside and outside of contemporary architecture. The result will show that the waterscape will be useful solution for healing of fundamental cause of psychological stress with sixteen psychological healing elements through compositional elements of waterscape.

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Generation and Physico-Chemical Characteristics of Municipal Solid Wastes generated in Chunchon for Sanitary Management (춘천시 생활쓰레기의 위생관리를 위한 배출 및 이·화학적 특성)

  • Rim, Jay-Myoung;Kang, Sung-Hwan;Han, Dong-Joon;Kim, Byeoung-Ug
    • Journal of Industrial Technology
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    • v.17
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    • pp.37-42
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    • 1997
  • Generation and physico-chemical characteristics of municipal solid wastes are very important for sanitary management. However, that has not been investigated so far especially in chunchon. And so, we tried to examine many things in detail. It was resulted that density was $90{\sim}94kg/m^3$ in school and office zone and $290{\sim}298kg/m^3$ in apartment and market place. The compositional weight fraction was food, 40~54%, paper, 14~18%, vinyl and prastic, 14~20% in house zone and market place and paper, 42~70% in school and office zone. Moisture was estimated to be 54~57% in independent house zone, apartment and market place and 11~23% in school and office zone. And three composition was water content, 44.1%, incineration particle, 11.2%, volatile parts, 44.7% in respectively. That is because of seasonal effects and regional chracteristics. In the results of chemical composition and caloric value analysis, carbon(C) was 80% in vinyl and plastic and oxygen(O) was 54.4% in paper.

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Optimization of the Ingredient Mixing Ratio for Preparation of Kiwifruit (Actinidia deliciosa) Jam Prepared with added Barley Sproutling Powder (어린 보릿잎을 첨가한 키위잼 재료 혼합비율의 최적화)

  • Jang, Myung-Sook
    • Korean journal of food and cookery science
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    • v.25 no.2
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    • pp.234-242
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    • 2009
  • This study was performed to find the optimum ratio of ingredients for the manufacture of kiwifruit jam. The experiment was designed according to the D-optimal design of RSM (response surface methodology), which included 18 experimental points with 4 replicates for three independent variables (sugar $35{\sim}60%$, pectin $0.1{\sim}1.0.%$, kiwifruit paste $0.37{\sim}0.90%$). The compositional and functional properties of the prepared products were measured, and these values were applied to mathematical models. A canonical form and trace plot showed the influence of each variable on the quality attributes of the final product mixture. By use of the F-test, viscosity, color values (L, a, b), and sensory characteristics (color) were expressed by a linear model, while the L color value and select sensory characteristics (smell, taste, overall acceptance) were also expressed by a quadratic model. The optimum formulations by the numerical and graphical methods, were similar, and with the numerical method it presented as: sugar, pectin, and barley sproutling powder at 49.7%, 0.5%, and 0.6%, respectively. The above results demonstrate the feasibility of preparing kiwifruit jam added with barley sproutling powder, and therefore, the commercialization of a kiwifruit jam marketed as a functional food is deemed possible.

Considerations on Digital Autobiography of the Elderly in the Digital Age (디지털 자서전 연구를 위한 고려사항 - 디지털 기기에 익숙한 노년을 대상으로)

  • Joo, Seoni;Kim, Hanil
    • Smart Media Journal
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    • v.8 no.3
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    • pp.80-87
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    • 2019
  • Older generations may want a life review, a dynamic process of recall, evaluation, and aggregation, to fulfill their developmental task of "ego-integrity." Writing an autobiography is a tool for a life review based on narrative as "mode of consciousness." This study intends to find out what should be considered so that digital autobiography can fulfill its original role as a tool to achieve ego-integrity for the New Silver Generation. For this purpose, we will first examine theories about the process of ego-integrity through a life review. Then we will analyze different aspects of writing an autobiography including three characteristics of being narrative and the compositional qualities of autobiographical writing. Next, we will review the characteristics of digital narratives autobiography, and highlight some ideas to consider in the study of digital autobiographies for the New Silver Generation.