• Title/Summary/Keyword: change of composition

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Composition and microstructure of Pb-Sn alloy electrodeposits in pulse plating with low peak current density (낮은 최고전류밀도 조건에서 파형전류전해에 의한 Pb-Sn합금 전착층의 조성 및 조작특성)

  • 예길촌;백민석
    • Journal of the Korean institute of surface engineering
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    • v.24 no.2
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    • pp.88-95
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    • 1991
  • The tin-lead alloy was electrodeposited in the low range of peak current density in order to investigate the change of composition and microstructure of them. The Pb content of alloy deposits, which was decreased with increasing average current density, was relatively lower than that of D.C. plated alloy deposit. The preferred orientation of alloy deposit was changed with increasing peak current density and the surface morphology of alloy deposits was closely related to the preferred orientation of them.

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A Study on Dimensional Change after Heat Treatment and Optimal Chemical Composition of Steels with 1200 MPa Tensile Strength for Automotive Subframe (인장강도 1200 MPa 급 자동차 서브 프레임의 합금성분 최적화 및 열변형 거동 연구)

  • Jeong, Woo Chang
    • Journal of the Korean Society for Heat Treatment
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    • v.33 no.3
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    • pp.107-116
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    • 2020
  • Four air hardening steels with carbon, silicon, manganese, chromium, and molybdenum variations have been used in this study to find out the optimal chemical compositions of steels with over 1200 MPa tensile strength for automotive subframe. The dimensional changes after heat treatment were determined for two automotive parts with open and closed cross sections using 3D scanner. When four steels were austenitized at 900℃ for 30 seconds, cooled at 3℃/s, reheated to 450℃ for 10 seconds followed by air cooling to simulate hot-dip galvanizing treatment showed ultra high tensile strength over 1200 MPa. Rear floor cross member with open cross section revealed much bigger dimensional changes than subframe with closed cross section after heat treatment at 900℃ for 20 minutes followed by air cooling.

Composition and microstructure of Silver-Tin alloy deposits from prophosphate bath (피로인산염욕을 사용한 은-주석 합금도금층의 조성 및 현미경 조직)

  • 예길촌;김용웅;김진수
    • Journal of the Korean institute of surface engineering
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    • v.26 no.3
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    • pp.143-148
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    • 1993
  • Composition and microstructures of Silver-Tin alloy deposits from a pyrophosphate bath were studied under the D.C. electrolysis conditions. Cathode current efficiency and throwing power of alloy deposits de-creased with increasing current density. Tin content of Ag-Sn alloy deposits decreased noticeably with the cur-rent density and with decreasing pH. The preferred orientation of the deposits tended to change in sequence of (110)longrightarrow(111)longrightarrow(100) texture with increasing the cathode overpotential. The surface structure of alloy deposits showed the smooth surface structure with fine crystallites.

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Water balance change at a transiting subtropical forest in Jeju Island

  • Kim, JiHyun;Jo, Kyungwoo;Kim, Jeongbin;Hong, Jinkyu;Jo, Sungsoo;Chun, Jung Hwa;Park, Chanwoo;Kim, Yeonjoo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.99-99
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    • 2022
  • Jeju island has a humid subtropical climate and this climate zone is expected to migrate northward toward the main land, Korea Peninsula, as temperature increases are accelerated. Vegetation type has been inevitably shifted along with the climatic change, having more subtropical species native in southeast Asia or even in Africa. With the forest composition shift, it becomes more important than ever to analyze the water balance of the forest wihth the ongoing as well as upcoming climate change. Here, we implemented the Ecosystem Demography Biosphere Model (ED2) by initializing the key variables using forest inventory data (diameter at breast height in 2012). Out of 10,000 parameter sets randomly generated from prior distribution distributions of each parameter (i.e., Monte-Carlo Method), we selected four behavioral parameter sets using remote-sensing data (LAI-MOD15A2H, GPP-MOD17A2H, and ET-MOD16A2, 8-days at 500-m during 2001-2005), and evaluated the performances using eddy-covariance carbon flux data (2012 Mar.-Sep. 30-min) and remote sensing data between 2006-2020. We simulated each of the four RCP scenarios (2.6, 4.5, 6.0, and 8.5) from four climate forcings (GFDL-ESM2M, HadGEM2-ES, IPSL-CM5A-LR, and MIROC5 from ISIMIP2b). Based on those 64 simulation sets, we estimate the changes in water balance resulting from the forest composition shift, and also uncertainty in the estimates and the sensitivity of the estimates to the parameters, climate forcings, and RCP scenarios.

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A Study on the Spatial Peculiarity of the Residential Environment - Centering around with the changes of the space of housing in the rural and fishing villages (주거환경의 공간적 특성에 관한 연구 - 농.어촌 주거공간의 변용를 중심으로 -)

  • 양택훈
    • Journal of the Korean housing association
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    • v.2 no.2
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    • pp.21-33
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    • 1991
  • In veiw of the results that the spatial peculiarity of the residential environment has been analyzed through the investigation of live on the change and use of the space of housing in the village of Bongsung, which is a traditional farming village of Cheju Island, and in the village of Hamo, which is a traditional fishing village of Cheju Island, a traditional constitution of space strongly remains in the village of Bongsungwhose family composition has been reductionized and implified, on the other side a tendency of extension or remodelling has been strongly appeared as well as a plot planning or a loose form has been appeared in the village of Hamo whose famiIy composition has been simplified and diversified and whose style of living has been also diversified, so the tianditional style which the yard has been surrounded with a stone wall has not remained. In the generation of 1970, a tendency to maintain the tranditional living style, to simply change for application, or to change for holding fast to the tradition was appeared, and the space of housing has been changed for the advanced modernization of life pattern since the generation of 1980. However, the traditional custom of life is continued.

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A Study on the Deformation of Folk Village (전통민속마을의 주거변형실태에 관한 연구 - 낙안민속마을을 중심으로 -)

  • Park, Ik-Soo
    • Journal of the Korean Institute of Rural Architecture
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    • v.6 no.3
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    • pp.63-74
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    • 2004
  • This study is focusing on the Nagan Folk Village, primarily because of its historical and cultural values. The purpose of this study, accordingly, analysis the fact of the dwelling change through spot-survey and case-investigation, and is to find a way to improve for the rational preservation of the traditional dwelling analyzing on the actual condition and the reason for such changes in the Nakan Folk Village. The dwelling change is stemmed from the physical factors, and some modifications of internal composition, exterior formation, building equipment. As a result, The changes of internal composition are included in the reduction of garnering room, the enlargement of bed/service room, the establishment of mechanical room. The changes of exterior formation with structural material are included in the glass door for the internalization of 'TOEMARU', the extra glass door for the brightening of room, the cement plastering for the endurance of wall. The changes of building equipment are included in the establishment of oil-boiler, wash closet, sink for convenient life All houses should be graded on their qualitative value, managed in a cycle. And its own criterion for acceptable deformations should be established.

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A Study on the Effects of Turmeric Intake after Weight Training on Blood Alcohol Concentration

  • KIM, Jun-Su;KIM, Young-Chul
    • The Korean Journal of Food & Health Convergence
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    • v.7 no.3
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    • pp.33-40
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    • 2021
  • The purpose of this study was to investigate the effects of turmeric intake and weight training on blood alcohol concentration, liver enzyme levels of and their effects on health promotion in adult males. There was no significant difference of taking turmeric powder combined with weight training exercise on blood alcohol levels in adult men who consumed alcohol on a regular basis. There was also no change on the change of body composition. The results were collected from elite athletes that had spent more than 10 years in their respective sports so it is difficult to observe any significant results from 8 weeks, short-term exercises of 1RM 70~80%, 3 times per week. In the next study, it is necessary to divide the subjects into more diverse groups and subject them by varying amounts of turmeric intake, exercise, etc., in order to fully study and understand the effects on blood alcohol level, change, and health promotion. Consequently, this study demonstrated there were no significant differences in the effects of continuous drinking habits of adult men's turmeric powder intake and weight training exercise on changes in GOT, GPT, γ-GTP, and blood alcohol concentrations. Moreover, health improvements themselves didn't affect changes in body composition.

The Investigation Study of Compaction Density by Waste Composition Change in Landfill Site (매립장의 반입쓰레기 성상변화에 따른 다짐밀도 조사연구)

  • Jung, Byung-Gil;Choi, Young-Ik;Kim, Jung-Kwon
    • Journal of Environmental Science International
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    • v.17 no.4
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    • pp.397-403
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    • 2008
  • The purpose of this study is to investigate weighted compaction density according to a leading density in truck, a compaction density of solid waste and composition ratios of solid waste fur calculation of a capacity of the landfill sites. The experiments for calculations of in-place density at landfill site have been conducted in S landfill site at B City. The size of vessel for measuring the compaction density was $1m^3(1m{\times}1m{\times}1m)$. The experiment tests have been carried out methods (1 time for bulldozer and 4 times for compactor) that do contain all of specification at the landfill site. Average of the loading density at the landfill site was $0.264\;ton/m^3$ ($0.113{\sim}0.487\;ton/m^3$). When the loading density for each compositions was compared, the composition of the highest average loading density ($0.474\;ton/m^3$) was miscellaneous wastes. The composition of the lowest average loading density ($0.120 ton/m^3$) was general solid waste. The reported results indicated that the compaction density at the landfill site was $0.538\;ton/m^3$, which was calculated with weighted incoming ratios of compositions. The ranges of the density for each composition were from $0.021\;ton/m^3$ to $0.221\;ton/m^3$. When the compaction density for each composition was compared, the composition with the highest average compaction density ($0.221\;ton/m^3$) was miscellaneous wastes. The composition with the lowest average compaction density ($0.021\;ton/m^3$) was general solid wastes.

A Study on the Changes of Dental Health System's Expertise and Spatial Composition according to Dental Specialist System Enforcement in Korea (한국 치과 전문의 제도 시행에 따른 치과 의료체계의 전문성과 공간구성의 변화에 관한 연구)

  • Jeong, Tae-Jong
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.36 no.5
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    • pp.33-40
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    • 2020
  • The purpose of this research is to provide the basic information for the development of dental healthcare system's expertise and spatial composition in diverse dental spaces in Korea according to dental specialist system enforcement. Literature review of dental expertise especially dental specialist system and investigation on current status of spatial composition of dental spaces have been conducted. After the review, the spatial composition with field survey and architectural drawings of selected dental spaces have been analyzed. The result of this study is arranged with three points. First of all, the main clinical dental spaces are the dental school's dental hospital, dental department in medical center/hospital and private dental clinic in Korea. The second one is that dental school's dental hospital had differentiated to 10-11 departments in 1970-1980's and dental department in medical center/hospital has been changing to dental hospital with 5-7 departments in 2010's, and dental clinic is changing to specific dental clinic according to dental specialist system in 2018. The third one is that spatial composition is related with dental expertise at diverse levels. Spatial composition in dental school's dental hospital had been highly differentiated with dental expertise, dental department in medical center/hospital is partially subdivided with dental specialist system, but that of dental clinic is not changed according to dental specialist system. In addition to current spatial composition according to dental expertise, it is necessary to analyze the change of spatial composition with diachronic methods to develop the dental healthcare system.