• Title/Summary/Keyword: well-mixed area

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A Study on Comparison of Changes in Ecological Characteristics for Bulgwangcheon(stream) Close-to Nature Section (불광천 자연형 하천 정비구간의 생태적 특성 변화 비교 연구)

  • Park, Won-Zei;Lee, Kyong-Jae;Han, Bong-Ho;Jang, Jae-Hoon
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.2
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    • pp.112-129
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    • 2012
  • The aim of this study was to provide basic data in managing the project that was carried out on Bulgwangcheon in a nature-friendly way to improve the conditions around the areas, which was brought to completion in 2002, based on changes in ecological characteristics. For this propose, this study examined documents related to the project, compared physical and enviromnental changes before and after the project was conducted and analyzed changes in the stream ecosystem. The result showed that in areas that effluent water was often observed, especially when it rained, the river wall was washed away and vegetation was found damaged. As for actual vegetation, this study compared planting coverage of each section of the research area and actual vegetation charts. The results indicated that Lespedeza spp., Aster koraiensis among mixed seeds that were planted in the reservoir path were almost swept away while Festuca arundinacea dominated the areas. Phragmites communis, Miscanthus sacchariflorns and Salix gracilistyla which had been planted in a small number were also almost washed out though a small number of them were left to form a colony. After examining the topography and structure of the plant community, this study found that areas where mixed seed were planted had changed into two types of vegetation: First type of area is dominated by P and R which are usually raised in apron with abundant floating particles. The second type of area is dominated by dry gramineous plant such as F and A. Areas around low flow channel where Phragmites communis, Miscanthus sacchariflorus and Salix gracilistyla planting construction method is applied was washed away with the width of low flow channel reduced. Though P, M and S formed a small community in some areas around the low flow area, they were in small number and in composition of simple plant species. Two ways were suggested in this study to manage the stream in an ecological way. First, adequate revetment construction methods should be applied by monitoring the flow of the stream as well as considering the flood control of urban streams. Second, target vegetation communities that are suitable for the environment of the stream should be chosen and be plantedconstantly with high density. At the same time, ornamental native plants shouldn't be planted as they have been and disturbing vegetation should be removed.

A Study on the Aesthetics of Dart Manipulation for Women's Body Types in Their 30's - Focused on the Bodice Prototypes - (30대 여성의 체형에 따른 다트매니플래이션의 심미성연구 - 상의 원형 중심으로 -)

  • Jeong, Jae-Chul;Kwon, Soon-Kyo;Park, Sun-Kyung
    • Journal of the Korean Society of Costume
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    • v.62 no.5
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    • pp.73-87
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    • 2012
  • The purpose of this study is to find the Dart Manipulation with good fitting and evaluate the aesthetics of Dart Manipulation that is used in the designs of the original tops for women in their 30's. Subsequently, it suggests dart manipulation with good body fitting and physical fitness when designing original tops. The findings of this study are as follows. First, in the fitting of Dart Manipulation for different body types, cross direction Dart Manipulation received good marks in the Square Body Type while mixed direction and diagonal direction Dart Manipulation received high evaluation in the Standard Body Type. Also, for the Reverse Triangle Body Type, mixed direction Dart Manipulation received high marks. Since there are only small changes in fitting for the Square Body Type, the position of Dart Manipulation should be determined in regards to the aesthetic view as well as the fitting of the Standard Body Type and Reverse Triangle Body Type. Second, in the fitness of Dart Manipulation for different body types, an approach from the aesthetic view should be considered for Square Body Types because of the differences in fitness according to the position of dart manipulation. The fitness should be considered when positioning Dart Manipulation for the Standard Body Type and Reverse Triangle Body Type because of these differences. Third, for the greater variance of drop for these different body types, the change of the amount of dart received lower evaluation in fitting since the amount of dart increased when the dart was located higher than B.P. The number of dart should likely increase when gathering or tucking is necessary when there is an excessive amount of dart in Dart Manipulation for the different body types. Fourth, as for the changes of wrinkles in accordance with the body type, wrinkles were likely to be formed at the breast or neck area when there was a larger difference in drop. To prevent such problems, one more dart should be made on the wrinkle. In conclusion, the study suggests designing the original top with a better look and comfort by setting the balance between aesthetics and fitting in the design stage.

A Study on Categorizing Subway Station Areas in Seoul by Rail Use Pattern (서울시 역세권의 유형화에 관한 연구 (요일별 시간대별 지하철 이용인구를 중심으로))

  • Sung, Hyun-Gon;Kim, Tae-Hyun
    • Journal of Korean Society of Transportation
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    • v.23 no.8 s.86
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    • pp.19-29
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    • 2005
  • The purpose of this study is to categorize subway station areas in Seoul by rail use characteristic. Most studies have categorized rail-oriented areas, based on land use patterns or/and urban spatial structure in Korea as well as the United States. However, the land use pattern of a subway station area tends to form by the real use of subway users since the latter plays an important role in forming the former. Therefore, the study is expected to contribute to the planning and policy of subway station areas in Seoul by analyzing characteristics of rail use. To achieve the purpose, the study uses a factor analysis for rail use, in terms of time of the day and day of the week. and then conducted a multidimensional scaling method to identify a relation of the real pattern to land use pattern. The results find that the Seoul subway station areas are categorized into residential, commercial and recreational, and office-centered ones. Furthermore, unlike the results of previous studies, the study identifies that many station areas have the mixed characteristics of economic activities. That is, they form more than a centered function such as residential and commercial, residential and office, commercial and office, residential, commercial and office. In addition, the study identifies that there is a close connection between rail use and land one. In short, identification of these mixed characteristics for subway station areas is expected to contribute to developing the planning and development method of TOD in Korea.

Characteristics and Improvement of Potential Acid Sulfate Soil Derived from Continental Materials on Alluvial Fan (선상지(扇床地) 육성(陸成) 잠재특이산성토(潛在特異酸性土)의 특성과 개량)

  • Jung, Yeun-Tae;Yun, Eul-Soo;Son, Il-Soo
    • Korean Journal of Soil Science and Fertilizer
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    • v.25 no.3
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    • pp.195-201
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    • 1992
  • A Potential acid sulfate soil derived from continental Holocene deposits on the fan-base was found and it was characterized with improvement practices. Artesian wells were scattered in the area, and the imperfectly drained soils were featured by having fine loamy with 7~30% of gravels. The potential acid sulfate soil layers were typified by having darkness in color with around 3.3~3.8% of O.M. and 0.34~0.41% of total sulfur. Soil pH ranged from 3.4 to 3.8 but it was decreased to 1.9~2.5 after oxidation with $H_2O_2$. Ground water sprang out from an artesian well contained a high amount of minerals such as Na, Ca, Mg, K, etc. and about 80ppm of sulfate which seemed to be responsible for pyrite formation. The soil was classified to member of "Fine loamy, mixed, acid, mesic, sulfic Haplaquepts" in taxonomically, and "weak potential acid sulfate soils" in interpretatively. The installation of tile drains with adding fine earth and liming were effective. However, the pH goes down to 4.8 again after 3 years of improvement practices.

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A Study on Characteristics of HI Decomposition Using Pt Catalysts on ZrO2-SiO2 Mixed Oxide (ZrO2-SiO2 복합산화물에 담지된 백금 촉매의 요오드화수소 분해 특성 연구)

  • Ko, Yunki;Park, Eunjung;Bae, Kikwang;Park, Chusik;Kang, Kyoungsoo;Cho, Wonchul;Jeong, Seonguk;Kim, Changhee;Kim, Young Ho
    • Transactions of the Korean hydrogen and new energy society
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    • v.24 no.5
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    • pp.359-366
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    • 2013
  • This work is investigated for the catalytic decomposition of hydrogen iodide (HI). Platinum was used as active material by loading on $ZrO_2-SiO_2$ mixed oxide in HI decomposition reaction. To obtain high and stable conversion of hydrogen iodide in severe condition, it was required to improve catalytic activity. For this reason, a method increasing dispersion of platinum was proposed in this study. In order to get high dispersion of platinum, zirconia was incorporated in silica by sol-gel synthesis. Incorporating zirconia influence increasing platinum dispersion and BET surface area as well as decreasing deactivation of catalysts. It should be able to stably product hydrogen for a long time because of inhibitive deactivation. HI decomposition reaction was carried out under the condition of $450^{\circ}C$ and 1 atm in a fixed bed reactor. Catalysts analysis methods such as $N_2$ adsorption/desorption analysis, X-ray diffraction, X-ray fluorescence, ICP-AES and CO gas chemisorption were used to measurement of their physico-chemical properties.

Micelle Formation of Surfactant Solution(3) -Self-Diffusion and 1H Relaxation for Mixed Micelle of Nonionic and Ionic Surfactants- (계면활성제 수용액에서 미셀형성(제3보) -비이온성과 이온성계면활성제의 혼합 미셀에 있어 자기확산 및 프로톤 이완-)

  • Choi, Seung-Ok;Kwack, Kwang-Soo;Park, Heung-Jo;Nam, Ki-Dae
    • Applied Chemistry for Engineering
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    • v.10 no.6
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    • pp.876-880
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    • 1999
  • The surfactant self-diffusion coefficients of mixed micellar solutions of ionic and nonionic surfactants have been measured by the NMR pulsed field gradient spin echo(FT-PGSE) method. In addition, the line widths of $^1H$ NMR signal have been monitored. The system investgated are $C_{12}EO_5/SDS/D_2O$, $C_{12}EO_5/DTAC/D_2O$, and $C_{12}EO_8/SDS/D_2O$. In the sample series, the molar ratios of $D_2O$ to surfactant(ionic+nonionic) were kept constant while the surfactant mixing ratio was varied. For the $C_{12}EO_5$ system, the surfactant self-diffusion coefficient indicates minimum when the surfactant mixing ratio is about 20% ionic surfactant. The observed decrease in self-diffusion coefficients as nonionic surfactant was replaced by ionic surfactant is interpreted to mainly be due to an increased micelle-micelle repulsion. The increase in self-diffusion coefficients occurring at higher fraction of ionic surfactant is shown to be due to a decrease in micelle size. For the $C_{12}EO_8$ system, the effect of the surfactant mixing ratio is much weaker which can be understood by considering the molecular geometry and large headgroup area. The proton NMR line widths correlate well with the self-diffusion coefficients and broadening of the alkyl chain methylene signals is found when the self-diffusion coefficients is low.

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Interdependence and Check in East Sea Rim: Focused on Border Trade n Transitional Nations (환동해권 지역사회의 상호의존과 견제: 제이행국가 접경지역의 대외경제교류 중심으로)

  • Choi, Youngjin
    • International Area Studies Review
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    • v.16 no.3
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    • pp.293-321
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    • 2012
  • This study aims to examine how institutions has been formed to deepen interdependence and to keep check in trade on the border regions of East Sea Rim between the macro structure and micro behaviors. The transitional nations such as China, Russia, and North Korea adjacent to the East Sea Rim exhibits unique characteristics in terms of transaction governance structure. While the regional economy in northeast China is still overwhelmed by the stated-owned enterprises(SOEs), it strongly encourages the private economic trade to form institutional economy through the border trade port and peddler trade market. Thus trade is shaped by the mixed governance. In far east Russia, whereas the SOEs are in charge of exporting oil, gas etc., private firms and small scale traders are importing household items, so that it can also be called as the mixed governance, while informal social networks simultaneously work. In North Korea, for the trade, since the firms are mainly required to have the permits from the different levels of government, it is regarded as the hierarchical governance. The institutional economics seems to well explain the changing agencies and their influence on the trade among the regions in the East Sea Rim.

Effects of Soil Types on Methane Gas Emission in Paddy During Rice Cultivation (논토양 종류가 메탄배출에 미치는 영향)

  • Seo, Young-Jin;Park, Jun-Hong;Kim, Chan-Yong;Kim, Jong-Su;Cho, Doo-Hyun;Choi, Seong-Yong;Park, So-Deuk;Jung, Hyun-Cheol;Lee, Deog-Bae;Kim, Kwang-Seop;Park, Man
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.6
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    • pp.1220-1225
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    • 2011
  • Anaerobic decomposition of organic materials in flooded rice fields produces methane ($CH_4$) gas, which escapes to the atmosphere primarily by transport through organs of the rice plants such as arenchyma etc., Although the annual amount of methane emitted from a given area is influenced by cultivation periods of rice and organic/inorganic amendments etc., soil type also affects methane emission from paddy soil during a rice cultivation. A field experiment was conducted to evaluate effects of soil type on $CH_4$ emission in two paddy soils. One is a red-yellow soil classified as a Hwadong series (fine, mixed, mesic family of Aquic Hapludalfs), and the other is a gley soil classified as a Shinheung series (fine loamy, mixed, nonacid, mesic family of Aeric Fluvaquentic Endoaquepts). During a flooded periods, redox potentials of red-yellow soil were significantly higher than gley soil. $CH_4$ emission in red-yellow soil ($0.21kg\;ha^{-1}\;day^{-1}$) was lower than that in gley soil ($5.25kg\;ha^{-1}\;day^{-1}$). In the condition of different soil types, $CH_4$ emissions were mainly influenced by the content of total free metal oxides in paddy soil. The results strongly imply that iron- or manganese-oxides of well ordered crystalline forms in soil such as goethite and hematite influenced on a $CH_4$ emission, which is crucial role as a $CH_4$ oxidizers in paddy soil during a rice cultivation.

The Origin and Geochemical Behavior of Fluoride in Bedrock Groundwater: A Case Study in Samseung Area (Boeun, Chungbuk) (화강암 지역 암반 지하수 내 불소 이온의 기원 및 거동: 충북 보은 삼승면 일대의 현장 조사와 실내 실험 연구)

  • Chae, Gi-Tak;Koh, Dong-Chan;Choi, Byoung-Young
    • The Journal of Engineering Geology
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    • v.18 no.4
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    • pp.555-566
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    • 2008
  • Hydrogeochemical study in Samseung area (Boeun, Chungbuk) and waterrock interaction experiment using rock samples from the area were performed to elucidate the fluoride source in groundwater and explaining geochemical behavior of fluoride ion. Fluoride concentration of public water supply mostly using groundwater in Boeun area was significantly higher in South Korea. The maximum fluoride concentration of the study area was 3.9 mg/L, and 23% of samples exceeded the Korean Drinking Water Standard of fluoride (1.5 mg/L). The average concentration of fluoride was 1.0 mg/L and median was 0.5 mg/L. Because of high skewness (1.3), median value is more appropriate to represent fluoride level of this area. The relationships between fluoride ion and geochemical parameters ($Na^+$, $HCO_3$, pH, etc.) indicated that the degree of waterrock interaction was not significant. However, high fluoride samples were observed in $NaHCO_3$ type on Piper's diagram. The negative relationship between fluoride and $NO_3$ ion which might originate from surface contaminants was obvious. These results indicate that fluoride ion in groundwater is geogenic origin. The source of fluoride was proved by waterrock interaction batch test. Fluoride concentration increased up to 1.2 mg/L after 96 hours of reaction between water and biotite granite. However, the relationship between well depth and fluoride ion, and groundwater age and fluoride ion was not clear. This indicates that fluoride ion is not correlated with degree of waterrock interaction in this area but local heterogeneity of fluoriderich minerals in granite terrain. High fluoride concentration in Boeun area seems to be correlated with distribution of permeable structures in hard rocks such as lineaments and faults of this area. This entails that the deep bedrock groundwater discharges through the permeable structures and mixed with shallow groundwater.

Dynamic Characteristics of Liquidity Filling Materials Mixed with Reclaimed Ash (매립석탄회를 혼합한 유동성 충진재의 동적거동특성)

  • Chae, Deokho;Kim, Kyoungo;Shin, Hyunyoung;Cho, Wanjei
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.4
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    • pp.5-11
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    • 2014
  • Recently, there have been various lifeline installations constructed in the underground space of urban area due to the effective use of land. For newly installed lifelines or the management of the installed lifelines, many construction activities of excavation and backfilling are observed. Around these area, there are possibilities of collapse or excessive settlement due to the leaking of the pipe or unsatisfactory compaction of backfill material. Besides, construction costs can be saved since the on-site soils are used. The application of this liquidity filling material is not only to the lifeline installation but also to underpin the foundation under the vibrating machinery. On the evaluation of the applicability of this method to this circumstance, the strength should be investigated against the static load from the machine load as well as the vibration load from the activation of the machine. In this study, the applicability of the liquidity fill material on the foundation under the vibrating machinery is assessed via uniaxial compression and resonant column tests. The liquidity filling material consisting of the on-site soils with loess and kaolinite are tested to investigate the static and dynamic characteristics. Furthermore, the applicability of the reclaimed ash categorized as an industrial waste is evaluated for the recycle of the waste to the construction materials. The experimental results show that the shear modulus and 7 day uniaxial strength of the liquidity filling material mixed with reclaimed ash show higher than those with the on-site soils. However, the damping ratio does not show any tendency on the mixed materials.