• Title/Summary/Keyword: man and natural environment

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Development of Control Technology for Acid Mine Drainage by Coating on the Surface of Pyrite using Chemicals (산성광산배수의 발생저감을 위한 황철석 표면의 피막형성 기술개발)

  • Ji, Min-Kyu;Yoon, Hyun-Sik;Ji, Eung-Do;Lee, Woo-Ram;Park, Young-Tae;Yang, Jung-Seok;Jeon, Byong-Hun;Shim, Yon-Sik;Kang, Man-Hee;Choi, Jae-Young
    • Journal of Soil and Groundwater Environment
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    • v.15 no.4
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    • pp.46-52
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    • 2010
  • Acid mine drainage occurs when sulfide minerals are exposed to an oxidizing environment. The objective of this study was to inhibit the oxidation of pyrite by applying various coating agent such as $KH_2PO_4$, MgO and $KMnO_4$ over its surface as an oxidation inhibitors. Experiments were conducted for 8 days to test the feasibility of oxidation inhibitors. The optimal condition of coating agent for standard pyrite and IK mine was the combination of 0.01M $KH_2PO_4$, 0.01M NaOAc and 0.01M NaClO. Otherwise, for YD mine the combination of 0.01M $KMnO_4$, 0.01M NaOAc and 0.01M NaClO. The $SO_4^{2-}$ reduction efficiency of pyrite, IK and YD mine samples was 70, 92 and 84%, respectively. For 8 days, no significant increase of $SO_4^{2-}$ from pyrite sample coated with inhibitor was observed. The pH of solution remains in between 4 to 6 for the reaction conditions.

Conjectual Study on Korean Costume in the Prehistoric Period (선사시대(先史時代)에 있었을 우리 민족복식(民族服飾)을 생각하며)

  • You, Hi-Kyung
    • Journal of the Korean Society of Costume
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    • v.5
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    • pp.7-11
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    • 1981
  • In the vast extent of time, man and his ancestors have existed on earth about 2,000,000 years. For Near-Man, they knew how to make fire and protected themselves with hairs. Old-Man covered their bodies with the skins of wild animals. New Man improved the quality, the range and ingenuity, so they fabricated clothes with the animal skins. New Man is considered as ancestor of Modern Man. They had spread widely over the earth to take advantage of their surroundings. The next period, New Stone Age was chiefly distinguished by agricultural age. He was now about to make clothes from natural fibers. The two most obvious orgins of clothing are to protect the body against environment and to decorate the body. The forms of clothing were different from the various climates and regions they had settled, for example Yo-po Hyung (Apron), Kwae-po Hung (Sewn garment), Kwan-doo Hyung (Poncho), Chun-kae Hyung (Frontopend garment), Chai-hyung Hyung (Body-conforming shape). Our ancestor had moved from Baikal Lake, Central Asia toward northeast; Shun-tung in China, Manchuria and at last Han Panninsula. Considering our basic costume of ancient times were Yu(jacket), Ko(trousers), Sang(skirt), Po (coat) with the accessories of Kwan (crown), Mo (hat), Dai (belt), Hwa, Eie (footwear), here I conjecture our costume of prehistoric period was Chaihyung Hyung(Body-conforming shape) in the purpose of body covering.

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A Study on the Microstructure and Mechanical Properties for the Weldment with Variation of Welding Process of the API 5L-B42 Pipeline for Natural Gas Transmission (천연가스 수송용 API 5L-X42 강관의 용접방법에따른 용접부의 미세조직과 기계적 특성에 관한 연구)

  • Baek Jong-Hyun;Kim Cheol-Man;Kim Young-Pyo;Kim Woo-Sik
    • 한국가스학회:학술대회논문집
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    • 1997.09a
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    • pp.33-38
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    • 1997
  • Demand of the clean and convenient natural gas has continuously increased with recognizing of the environment problem since liquefied natural gas was introduced in Korea. Clean fuel natural gas was supplied to each city through high tensile strength pipeline connected by welding. Grades of pipeline were divided into the high and middle pressure according to supply pressure. Pipeline was welded mainly SMA welding process due to its easy handling, the other welding process was adopted according to the constructing condition. We were examined on the microstructure variation and mechanical properties of weld metal for high pressure pipeline, API 5L X-42.

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City's Ecological Landscape in the Digital Age (디지털 시대 도시의 생태적 전망)

  • Lee, Kyung-Lae;Park, Kyou-Hyun;Cho, Yeon-Jung
    • Cross-Cultural Studies
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    • v.26
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    • pp.297-319
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    • 2012
  • We all know how beautiful our wild and it's importance to our living planet Earth. But did you realise the speed at which man himself is damaging it's unique natural habitat. We are well on our way to destroy our forests, plants, wetlands. We are polluting our oceans and seas. This way, we're driving numerous animal species, plant species and many others into extinction. Everyone should be aware of the importance of our natural environment. We live in the period of echocide. Why we need nature to survive and how we can deal with the environmental problems we face. This paper has the purpose to reform city's environment. Because, Metropolis and megalopolis are the principal cause of environmental disruption. To reform the city is needed to consider digital technology in our age. In the face of economic and cultural globalization, many have argued that we live an increasingly placeless world. However, as a growing number of cities participate and compete in key marketplaces of advanced capitalism, the spectacle of the city is more than ever a significant medium of communication in its own right. In doing so, this work is focused specifically on the dimension of city's media environment. To that end, the paper examined U-City and U-Eco city. In this study, we will introduce the study on model of U-Eco City as one way for the eco-freindly future city.

Effect of Agar, Sodium Alginate and Carrageenan on Quality of Yugwa(Busuge)Base (한천, Sodium Alginate 및 Carrageenan첨가가 유과(부수게)바탕의 품질에 미치는 영향)

  • Kim, Joong-Man;Jeon, Ye-Jeoung;Park, Hyo-Suk;Song, Young-Ae;Baek, Seung-Hwa;Kim, Myung-Kon
    • Journal of the Korean Society of Food Culture
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    • v.20 no.1
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    • pp.96-102
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    • 2005
  • This study was to evaluate effects of agar, sodium alginate and carrageenan on quality of Yugwa(Busuge) base. In the base preparation agar, sodium alginate and carrageenan were added 0.0, 0.1, 0.5, 1.0 and 3.0%(w/w), respectively. Volume, shape, hardness, color(L, a and b value), crude lipid content and sensory evaluation(taste and crispness) of the Yugwa base was measured. Volume of the base was higher than control in case of 0.1-0.5%(w/w) agar, sodium alginate and carrageenan, of which sodium alginate was the highest. Shapes were similar to control. Hardness and crude lipid content was decreased proportional to amount of addition of the three seesweed polysaccharides, the whiteness(L-value) was increased but the yellowness(a-value) and the redness(b-value) decreased. Taste and crispness were increased in the case of 0.1-1.0%(w/w) of sodium alginate, but agar and carrageenan decreased.

Flood Characteristics at Nakdong Estuary with 1 Dimensional Unsteady Model (1차원 부정류 모형을 활용한 낙동강 하류의 홍수 특성)

  • Lee, Sang-jin;Shin, Hyun-Ho;Kim, Joo-Cheol;Hwang, Man-Ha
    • Journal of Environmental Science International
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    • v.19 no.2
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    • pp.149-155
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    • 2010
  • Rainfalls would increase the discharges or stages of tributary channels in natural watersheds, which in turn augment the magnitude of main stream stages. Rising of water surface elevation in main streams can affect and damage the human activities because of the possibilities of the breakdown or overflow of the embankment. Therefore it is necessary to establish the structural or non-structural alternatives for the sake of prevention or treatment of those disasters. Many mathematical models to analyze the flood flows in natural watercourses have been proposed as the non-structural alternatives so far. In this study one of the such models, FLDWAV developed by NWS(National weather Service), is applied to the downstream reach of Nakdong river. Model calibration is performed on various Manning's roughness coefficients at the gauging stations. The simulation results are compared well with hydrological estimations of flood discharges considering the effects of multipurpose dams upstream of control points.

Thre Traditional Perception and Viewpoint to Natural Environment in the Orient (동양의 전통적 환경인식과 환경관)

  • 오홍석
    • Hwankyungkyoyuk
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    • v.3 no.1
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    • pp.55-62
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    • 1992
  • In the orient, ancestor's perception to natural environment was related on the change of climate. Man had been a essence of the warm blood animal, which had suited in mild climate for living and acting. The weather of hot or cold was not only comfort in human life but influences negatively on human behavior. The most people of oriental was particularly interrelated to seasonal change of climate in earlier time. Because, there are elements such as temperature, humidity and wind in the category of climate, these elements differentiated seasonal change. The main methods of perception of natural environment were observed and classified. Although these methods were in the primitive stage, these coincided the tendency of modern science. For example, confucian was recognized the law of vertical air current that warm air rised and cold air sinked. And they could classify all elements nature based on the principles of 'Yin and Yang(陰陽論)' such as male and female, the sun and moon. shade and light etc. Thus results of the observation and the classification concerned with physical environment can be utilize a wisdom for progressive life of inhabitants. It was a origin of the education in natural environment. Commonness in the viewpoint of environment in the orient if recognized the law of circulation. Buddhism, originated in india, realized that all of phenomena in the world was changed slowly through the principles of cycle(輪廻說) such as male and female, the sun and moon, shade and light etc. Thus results of the observation and the classification concerned with physical environment can be utilized a wisdom for progressive life of inhabitants. It was a origin of the education in natural environment. Commonness in the viewpoint of environment in the orient if recognized the law of circulation. Buddhism, originated in India, realized that all of phenomena in the world was changed slowly through the principles of cycle(輪廻說). For example, whole of land is shifted from young stage to old stage as the life cycle of humanbeing. The theory of karma effects(葉報設) is so signify with the good result that good one's action is reap a sweet fruit. The most environmental problem in today must realized as a consequence of men's act. Then Taoism emphasized the pure nature without the artificiality. Because complexual environment was composed of several elements, It was maintained through the artificiality. Because complexual environment was composed of several elements, It was maintained through the interaction of cause and effects. The solution of environmental problem is maintenanced the harmony between cause and effects by a philosophical concept.

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Properties Analysis of Environment Friendly Electrodeposit Films Formed at Various Current Density Conditions in Natural Seawater (천연해수 중 전류밀도 변화에 따라 형성된 환경친화적인 전착 코팅막의 특성 분석)

  • Lee Chan-Sik;Bae Il-Yong;Kim Ki-Joon;Moon Kyung-Man;Lee Myeong-Hoon
    • Journal of Surface Science and Engineering
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    • v.37 no.5
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    • pp.253-262
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    • 2004
  • Calcareous deposits are the consequence of pH increase of the electrolyte adjacent to metal surface affected by cathodic current in seawater. It obviously has several advantages over conventional coatings, since the calcareous deposit coating is formed from coating (Mg$^{2+}$, $Ca^{2+}$) naturally existing in seawater. In consideration of this respect, environment friendly calcareous deposit films were formed by an electro deposition technique on steel substrates submerged in 48$^{\circ}C$ natural seawater. And the influence of current density, coating time and attachment of steel mesh on composition ratio, structure and morphology of the electrodeposited films were investigated by Scanning Electron Microscopy(SEM), Energy Dispersive Spectroscopy(EDS) and X-Ray Diffractor(XRD), respectively. Accordingly, this study provides a better understanding of the composition between the growth of $Mg(OH)_2$ and $CaCO_3$ during the formation of electro deposit films on steel substrate under cathodically electrodeposition in $48^{\circ}C$ natural seawater. The Mg compositions, in general, are getting decreased regardless of current density but Ca compositions are getting increased as electrodeposition time runs. That is, $Mg(OH)_2$ compounds of brucite structure shaped as flat type is formed at the initial stage of electrodeposition, but CaCO$_3$ compounds of aragonite structure shaped as flower type is formed in large scale. Besides, $Mg(OH)_2$ compounds were much formed at 5 A/$\m^2$ environment condition compared to the 3 A/$\m^2$ and 4 A/$\m^2$ environment conditions. This is because that OH- which was comparatively largely generated at the metal surface is preferably combined with $Mg^{2+}$TEX>.

Estimation for River Naturality in the Hwang River (황강 수생태계에 대한 하천 자연도 평가 연구)

  • Huh, Man-Kyu
    • Journal of Environmental Science International
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    • v.22 no.2
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    • pp.195-203
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    • 2013
  • I investigated the river morphology and river naturality according to the environment of the Hwang River. The numbers of flexions at the upstream regions were more than those of downstream regions. The Hwang River showed very low overall diversity of the flow. Materials of river shore at low channel width were mainly boulders or gravel at the upstream regions, and the middle and downstream were silts and clay. Artificial masonry and natural materials were mixed from materials of river levees. The Hwang River was some of the natural herbaceous vegetation to riparian zones. Land utilities for floodplain were extremely overall farmland were predominant, and partly used by natural vegetation in the forest, a soccer field, some park facilities, residential, and commercial facilities. The water was width sleep / rivers beam ratio of 10 to 20%. Currently estimation for river naturality widely used in rivers were consisted of a narrow wide a variety of items and did not reflect the actual.

Development of a Holographic Interferometric Tomography System and Its Application to Three-Dimensional Natural Convection (홀로그래피 간섭 토모그래피 개발 및 3차원 자연대류 열전달에의 적용)

  • Lee, Soo-Man;Kang, Min-Gu;Cha, Dong-Jin;Joo, Won-Jong;Kang, Bo-Seon
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1609-1614
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    • 2003
  • In this study, a practical holographic interferometric tomography system, which is instantaneous and non-contact for measuring three dimensional flow field, was developed. The system consists of holographic recording/reconstruction system, fringe analysis code and computational tomography code and it is developed with Gill environment for general users. The developed system was applied to three-dimensional natural convection from a discrete flush-mounted circular heat source on the bottom of a cubic enclosure. The heat source was located at the off-center of the bottom plate so that three-dimensional temperature field can be achieved. A set of multi-directional holographic interferograms was recorded by employing a double-reference beam, double-exposure holographic technique. Optical pathlength data were extracted from the recorded interferometric data and finally three dimensional temperature field inside the cube was reconstructed.

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