• Title/Summary/Keyword: Environmental issue

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An Ecological Aesthetic in Sustainable Landscape Design (지속가능한 조경설계에 있어서 생태미학적 접근)

  • Min, Byoung-Wook
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.2
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    • pp.38-48
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    • 2012
  • Since the late 20th century, sustainability is one of the most pressing concerns for the security and well-being of our society when we are witnessing the rapid change in urban landscape patterns. Responding to this issue, the discipline of environmental designs including landscape architecture has also attempted to realize this concept in various ways. The purpose of this study lies in introducing and redefining the meaning of ecological aesthetics as an alternative "sustainable" design theory. This paper theoretically discusses about the role of aesthetics in landscape design and the relationship between landscape and aesthetics to emphasize the importance of ecological aesthetics. Based on extensive literature review and analysis, the study attempts to redefine the characteristics of ecological aesthetics: an emphasis on cognitive process in landscape appreciation, environmentalism, unrestricted from style, and nonnative aesthetics. Having defined the characteristics, this study also finds several design subjects to adapt the concept of ecological aesthetics to actual design practice. Founded on the big idea "make nature visible", the defined subjects are ecological functions, temporality of landscape, and history of landscape, security, and accessibility. Also, this study stresses the importance m the creativity of the design(er) in order to effectively represent these subjects to the public.

Separation of Valuable Metal from Waste Photovoltaic Ribbon through Extraction and Precipitation

  • Chen, Wei-Sheng;Chen, Yen-Jung;Yueh, Kai-Chieh
    • Resources Recycling
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    • v.29 no.2
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    • pp.69-77
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    • 2020
  • With rapid increasing production and installation, recycling of photovoltaic modules has become the main issue. According to the research, the accumulation of waste modules will reach to 8600 tons in 2030. Moreover, Crystalline-silicon (c-Si) Photovoltaic modules account for more than 90% of the waste. C-Si PV modules contain 1.3% of weight of photovoltaic ribbon inside which contains the most of lead, tin and copper in the PV modules, which would cause environmental and humility problem. This study provided a valuable metal separation process for PV ribbons. Ribbons content 82.1% of Cu, 8.9% of Sn, 5.2% of Pb, and 3.1% of Ag. All of them were leached by 3M of hydrochloric acid in the optimal condition. Ag was halogenated to AgCl and precipitated. Cu ion was extracted and separated from Pb and Sn by Lix984N then stripped by 3M H2SO4. The effect of the optimal parameters of extraction was also studied in this essay. The maximum extraction efficiency of Cu ion was 99.64%. The separation condition of Pb and Sn were obtained by adjusting the pH value to 4 thought ammonia to precipitate and separate Pb and Sn. The recovery of Pb and Sn can reach 99%.

The Effect of STEAM Program using Arduino on Preservice Science Teachers' STEAM Core Competencies (아두이노를 활용한 STEAM 프로그램이 예비 과학교사의 융합인재 핵심역량에 미치는 영향)

  • Kim, Sun Young;Hyun, Yun Se
    • Journal of Science Education
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    • v.44 no.2
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    • pp.183-196
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    • 2020
  • This study explores the effects of STEAM program using Arduino on preservice science teachers toward their STEAM core competencies. The STEAM program using Arduino consists of four stages: presentation of situation, creative design, emotional touch, and evaluation. The preservice science teachers learned the theoretical backgrounds of STEAM and Arduino. Then, they were given the chance to think about an environmental issue, which is fine dust. The preservice teachers designed an air cleaner and a fine dust measuring instrument using Arduino. The preservice science teachers also produced the air cleaner and the measuring instrument using Arduino. They measured the level of fine dust in the classroom before and after the use of the air cleaner. That is, the preservice teachers experienced each stage of STEAM: seriousness of fine dust, design and production of the measuring instrument of fine dust and air cleaner, and evaluation of the effectiveness of air cleaner. Further, they reflected on their experiences of STEAM program using Arduino. The results indicate that these preservice science teachers statistically improved communication competency, problem-solving competency, gathering information competency, logical analytical thinking competency, and creativity competency. However, there were no statistical improvements on teamwork competency and self-development competency. This study suggests that experiencing STEAM program using Arduino is valuable for the preservice science teachers to develop STEAM core competencies and further implement STEAM program their science classes in the future.

A Study on the Climate Change and the Policy of Natural Gas Exploitation on the Arctic Region (기후변화와 북극 유·가스전 개발에 관한 연구)

  • Kim, Boyoung;Ryu, Siho;Park, Yonhe
    • Environmental and Resource Economics Review
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    • v.18 no.4
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    • pp.787-813
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    • 2009
  • Because of global warming, the thawing of the Arctic ice cap is slowly accelerating. That is the hot issue nowadays. According to the each country's climate change policy, it is boom in the world to lessen the consuming of the fossil fuel those are oil, coal and natural gas. But on the contrary the thawing of the Arctic ice cap is the chance to make the natural gas producing unit cost lower. The purpose of this paper is to search the Arctic policy of each country under the contradictory relationship between promoting the climate change policy and exploiting the natural gas on the Arctic. Specially, there are huge natural gas reserves in Russia on the Arctic region, Russia's exploiting the natural gas on the Arctic will affect on the natural gas supply-demand balance of world natural gas market strongly in the future. Therefore it needs to prepare the future energy alternative policy for Korea's energy security. Russia has Yamal Peninsular where is abundant on natural gas reserver, and she can supply natural gas by LNG ship all over the world via the Arctic route. This means that the structure of world natural gas market be changed gradually. It will be possible in 2030~2040. And such a change is very important because new natural gas trading type can do it through not only overcoming the geological restriction but also shifting the main trading type from PNG(Pipeline Natural Gas) to LNG(Liquified Natural Gas). Therefore it is necessary that we should let this be a good lesson to ourselves through the government action of other countries (China, Japan) those also have no sovereignty over the Arctic as Korea.

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Anti-inflammatory activity of a sulfated polysaccharide isolated from an enzymatic digest of brown seaweed Sargassum horneri in RAW 264.7 cells

  • Sanjeewa, Kalu Kapuge Asanka;Fernando, Ilekkuttige Priyan Shanura;Kim, Eun-A;Ahn, Ginnae;Jee, Youngheun;Jeon, You-Jin
    • Nutrition Research and Practice
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    • v.11 no.1
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    • pp.3-10
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    • 2017
  • BACKGROUND/OBJECTIVES: Sargassum horneri is an edible brown alga that grows in the subtidal zone as an annual species along the coasts of South Korea, China, and Japan. Recently, an extreme amount of S. horneri moved into the coasts of Jeju Island from the east coast of China, which made huge economic and environmental loss to the Jeju Island. Thus, utilization of this biomass becomes a big issue with the local authorities. Therefore, the present study was performed to evaluate the anti-inflammatory potential of crude polysaccharides (CPs) extracted from S. horneri China strain in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. MATERIALS/METHODS: CPs were precipitated from S. horneri digests prepared by enzyme assistant extraction using four food-grade enzymes (AMG, Celluclast, Viscozyme, and Alcalase). The production levels of nitric oxide (NO) and pro-inflammatory cytokines, including tumor necrosis factor (TNF)-${\alpha}$ and interleukin (IL)-$1{\beta}$ were measured by Griess assay and enzyme-linked immunosorbent assay, respectively. The levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), nuclear factor (NF)-${\kappa}B$, and mitogen-activated protein kinases (MAPKs) were measured by using western blot. The IR spectrums of the CPs were recorded using a fourier transform infrared spectroscopy (FT-IR) spectrometer. RESULTS: The polysaccharides from the Celluclast enzyme digest (CCP) showed the highest inhibition of NO production in LPS-stimulated RAW 264.7 cells ($IC_{50}$ value: $95.7{\mu}g/mL$). Also, CCP dose-dependently down-regulated the protein expression levels of iNOS and COX-2 as well as the production of inflammatory cytokines, including TNF-${\alpha}$ and IL-$1{\beta}$, compared to the only LPS-treated cells. In addition, CCP inhibited the activation of NF-${\kappa}B$ p50 and p65 and the phosphorylation of MAPKs, including p38 and extracellular signal-regulated kinase, in LPS-stimulated RAW 264.7 cells. Furthermore, FT-IR analysis showed that the FT-IR spectrum of CCP is similar to that of commercial fucoidan. CONCLUSIONS: Our results suggest that CCP has anti-inflammatory activities and is a potential candidate for the formulation of a functional food ingredient or/and drug to treat inflammatory diseases.

Effect on the Fuel Economy by Gradient in Automobile Driveway (자동차 전용도로에서 경사가 연비에 미치는 영향)

  • Choi, Seong-Cheol;Oh, Tae-Il
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.7
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    • pp.2925-2930
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    • 2011
  • A vehicle fuel economy is very important issue in the view of fuel cost and environmental regulation. The fuel economy is much improved according to the development of electric, electronic and mechanical technology, but up to now the measurement of it tests the given mode(LA-4, FTP-75, etc) within computer simulation program and engine dynamometer. This fuel economy is different with it of real road. The one of main reason is not considered the gradient of the road. To estimate the effects of fuel economy at highway with gradient in this paper, we measure the amount of fuel consumption and calculate the fuel economy of it with running the Youngdong highway with high gradient. Also this paper analysis and compares the fuel economy with gradient and without gradient when the vehicle runs the same driveway. Then we calculate the total energy created the difference of fuel consumption amount of the two cases and calculate the consumpted energy by tire driving force from the torque and power of engine in the simulation. This paper verifies the relation of the driving force and the total energy by creating the difference of fuel consumption amount. This paper also proposes the method of fuel economy improvement despite of gradient at the result.

Development of State of Charge and Life Cycle Evaluation Algorithm for Secondary Battery (이차전지의 상태 감시 및 수명 예측 알고리즘 개발)

  • Park, Jaebeom;Kim, Byeonggi;Song, Seokhwan;Rho, Daeseok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.1
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    • pp.369-377
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    • 2013
  • This paper deals with the state of charge(SOC) and life cycle evaluation algorithm for lead-acid battery, which is essential factor of the electric vehicle(EV) and the stabilization of renewable energy in the smart grid. In order to perform the effective operation of the lead-acid battery, SOC and life cycle evaluation algorithm is required. Specific gravity with the change of electrolyte temperature inside battery case should be obtained to evaluate the SOC of lead-acid battery, however it is difficult to measure the electrolyte temperature of sealed type lead-acid battery. To overcome this problem, this paper proposes the equation of thermal transmission to compensate internal temperature of the lead-acid battery. Also, it is difficult to exactly evaluate the life cycle of battery, depending on the operation conditions of lead-acid battery such as charging and discharging state, self discharging rate and environmental issue. In order to solve the problem, this paper presents the concept for gravity accumulation of charge and discharge cycle, which is the value converted at $20^{\circ}C$. By using the proposed algorithm, this paper propose the test device based on the Labview software. The simulation results show that it is a practical tool for the maintenance of lead-acid battery in the field of industry.

Analysis on the Ore Recovery from Operating the Room & Pillar Hybrid Mining Method in the Korean Limestone Mine (국내 석회석 광산에서 주방식하이브리드 채광법의 채수율 분석)

  • Kwon, Dukjoon;Kim, Jaedong
    • Tunnel and Underground Space
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    • v.27 no.3
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    • pp.161-171
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    • 2017
  • Demand for high-grade limestone is increasing, but the production in the domestic mines has been limited due to the lack of systematic development plans and efforts to develop mining technology to improve the recovery ratio, transition to high-cost underground mining due to increasing social awareness of environmental protection, and the smallness of the domestic mining industry, etc. In this study in connection with this issue, an analysis on the recovery change by improvement of mining method was executed. 3D modeling technique was used to construct a 3D model. 3D model includes the geological structure, the limestone ore body and the underground pits and tunnels excavated at the Daepyeong District of Daesung MDI Donghae District. By using the 3D model, measured resources, reserves and ore recovery were evaluated from the results of pilot operation of the room and pillar hybrid mining method, which is a variant of room and pillar mining method. These results were compared with those obtained from the conventional mining method. The ore recovery obtained by hybrid mining method was found to be up to 71.6%, showing about 26%p. increase compared with the case of conventional mining method.

Effects of Chogam-Tang on Rat Skin Induced the Allergic Contact Dermatitis (백서(白鼠)에 유도된 알러지성 피부염에 대한 초감탕(椒甘湯)의 효과)

  • Yoon, Hui-Sung;Park, Owe-Suk;Kim, Hee-Jeong;Kim, Keoo-Seok;Kim, Yoon-Bum
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.18 no.3
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    • pp.44-54
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    • 2005
  • Background and Objectives: Allergic contact dermatitis is a common environmental health issue and seriously affect the patient's quality of life. The more our environment industrialized, the number of material that could cause the allergic contact dermatitis has been increased, consequently the prevalence of allergic contact dermatitis has been increased. In oriental medicine, clinically Chogam-Tang has been used fur the treatment of allergic dermatitis, eczema, atopic dermatitis etc. The objective of this study is to investigate the effects of Chogam-Tang on allergic contact dermatitis Meterial and Methods: Fifteen Sprague-Dawley rats were divided into three groups: normal, control, experimental group. Control and experimental group were induced allergic contact dermatitis, by DNCB. Experimental group was orally administered the Chogam-Tang. Each group was observed after 24, 48 and 72 hours. Contact hypersensitivity assay, melanin-erythema measurement, pH measurement skin moisture measurement and biopsy were performed. Results: 1. In contact hypersensitivity assay, experimental group showed decreased ear swelling compared with control group at 48hours. 2. ln melanin measurement there was no difference in three groups. 3. In erythema measurement experimental group showed reduction at 48. 72 hours. 4. In pH measurement, experimental group and control group showed increase in pH but there was no statistical significance. 5. In skin moisture measurement, experimental group showed higher skin moisture level than control group at 24 hours and showed lower skin moisture level at 72 hours, but there was no statistical significance. 6. In biopsy, experimental group showed decrement of Iymphocyte as time goes by, and regeneration of keratin layer was increased compared with normal group. Conclusions: Chogam-Tang shows anti-inflammatory effect in biopsy, improves hydration levels of skin, decreases erythema level on allergic contact dermatitis.

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Hydropower Development and Sustainability in the Mekong River Basin

  • Lee, Seung-Ho
    • Proceedings of the Korea Water Resources Association Conference
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    • 2012.05a
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    • pp.37-37
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    • 2012
  • The study aims to evaluate the complexity of relationships between the riparian states - China, Myanmar, Laos, Thailand, Vietnam and Cambodia - in the Mekong River Basin since the mid-1990s with special reference to the discourse on hydropower development. A special emphasis will be put on the influence of China on hydropower development. Although a variety of issues on the river basin have been discussed among the riparian states, none of them has been effectively implemented owing to the lack of China's commitment to the discussions for sustainable water management. Now, a new turning point is observed in the region with emergence of the issue on hydropower development, not only in the upper basin but also in the lower basin. The discourse on hydropower in Mekong has quickly drawn attention of the public, accelerated by the onset of construction of the Xayabury Dam in Laos since November 2010. The influence of China as the upstream country with its political, economic, and military power has increasingly grown in the region over the last few decades, and such trend recently intensifies together with an expansion of Chinese commercial interests in the region. Since the establishment of the Mekong River Commission (MRC) in 1995, the four MRC members have striven to push forward a sustainable use of water resources in the basin. But the legitimacy of the MRC system has been eroded due to the lack of participation by Myanmar and China, and in particular, the Chinese absence has made the four riparian states blind about the change of water regime due to the Chinese dams upstream. Environmental damages due to hydropower development might be possible, including a drop of fish yields, crop production, and damages to the river's ecosystems. Vietnam and Cambodia have already expressed their concerns over the dam construction towards China as well as Laos by pointing out detrimental impacts of the dams to their economies. China's move to collaborate with the other riparian states since 2010 has given a positive signal in terms of sustainable water management in the river. However, this phenomenon never confirms China's proactive contribution to the cooperative activities within the framework of the MRC system. Laos' initiative to build a new dam in the lower basin alarms those who are opposed to dam construction in the fear of its far-reaching damages to the environment. The question goes back to the year-long debate on policy priorities given to economic growth or the environment. The riparian states require wisdom based on a consensus about sustainable water use rather than hydropower development based on individual growth dreams.

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