• 제목/요약/키워드: Green city

검색결과 976건 처리시간 0.025초

페로브스카이트 촉매에 의한 액화수소의 올소-파라 수소변환특성에 관한 연구 (A Study on the Ortho-para Hydrogen Conversion Characteristics of Liquefied Hydrogen by Perovskite Catalysts)

  • 나인욱;김정현;;권순철;오인환
    • 한국수소및신에너지학회논문집
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    • 제26권1호
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    • pp.15-20
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    • 2015
  • During the liquefaction of hydrogen, the ortho hydrogen is converted into the para form with heat release that evaporates the liquefied hydrogen into the gaseous one backwards. The ortho-para conversion catalysts are usually used during liquefaction to avoid such boil-off. In order to compare and analyze the performance of the ortho-para hydrogen conversion catalysts, in-situ FT-IR device was designed and manufactured to measure the para hydrogen conversion rate in real-time. $LaFeO_3$ and $La_{0.7}Sr_{0.3}Cu_{0.3}Fe_{0.7}O_3$ perovskite catalysts were prepared by the citrate sol-gel method and their spin conversion characteristics from ortho to para hydrogen were investigated by in-situ FTIR spectroscopy at 17K. It was found that the spin conversion was affected by surface area, particle size, and crystallite size of the catalysts. Thus, the $La_{0.7}Sr_{0.3}Cu_{0.3}Fe_{0.7}O_3$ perovskite catalyst that had higher surface area, higher crystallite size, and smaller particle size than $LaFeO_3$ showed the better spin conversion property of 32.3% at 17K in 120min interaction with the perovskite catalysts.

로컬거버넌스의 형성과 제도화: 청주시 초록마을사업 사례연구 (Formation and Institutionalization of Local Governance : A Case Study on the Green Village Project in Cheongju City)

  • 하민철
    • 한국융합학회논문지
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    • 제11권1호
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    • pp.247-257
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    • 2020
  • 본 연구는 2010년 청주시에서 시작된 초록마을사업의 지난 10년간 성과를 검토하고, 로컬거버넌스의 형성과 제도화 가능성을 확인하는 데 목적이 있다. 환경운동단체 주도로 처음 시작된 거버넌스형 사업이 10년간 지속적이고 안정적으로 추진되고 있으며, 청주시 등 다른 참여주체들에 의해 당연히 추진해야 할 사업으로 인식되고 있다는 것은 매우 의미 있는 성과이다. 분석 결과, 초록마을사업을 추진하는 거버넌스 참여 주체들은 사업 참여가 자신들에게 이익이 된다는 합리적 선택의 판단에 근거하여 참여하고 있다. 그리고 참여 주체들은 초록마을사업이 정당성을 갖춘 사업으로 인식하고 있으며, 거버넌스 참여 과정에서 서로에 대한 신뢰를 축적하고 있고, 지속적으로 성공 경험을 하고 있음을 확인하였다. 결론적으로 초록마을사업의 지속성과 안정성이 강화되는 것을 확인할 수 있었으며, 초록마을사업 추진의 거버넌스가 제도화될 가능성이 더 높아졌음을 확인하였다.

Study of Urban Land Cover Changes Relative to Demographic and Residential Form Changes: A Case Study of Wonju City, Korea

  • Han, Gab-Soo;Kim, Mintai
    • Journal of Forest and Environmental Science
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    • 제31권4호
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    • pp.288-296
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    • 2015
  • In many very high density cities in Asia in which there is limited area to expand, growth is forced upward as well as outward. Densely packed detached houses and low-rise buildings are replaced by lower density high-rises, leaving open spaces between high-rise buildings. Through this process, areas that formerly did not have much green space gain valuable green spaces, and new ecological corridors and patches are created. In this study, the demographic and housing-type changes of Wonju City were delineated using land use maps, aerial images, census data, and other administrative data. Green area changes were calculated using land cover data derived from multi-year Landsat TM satellite imagery. The values were then compared against demographic and housing-type changes for each administrative unit. The overall results showed a decrease of forested area in the city and an increase of developed area. Urban sprawl was clearly visible in many of the suburban areas. However, as expected, we also detected areas in which greenness did not decrease when the population greatly increased. These areas were characterized by residential building complexes of ten or more stories. If an equal number of housing units had been built as detached houses, these areas would not have kept as much green space. Our research result showed that high-density and high-rise residential structures can offer an alternative means to protect or create urban green spaces in high-density urban environments.

옥상녹화 조성에 따른 열환경 변화분석 (An Analysis of Thermal Environment Change according to Green Roof System)

  • 박지영;정응호;김대욱;차재규;시미즈 아키
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 2009년도 추계학술발표대회 논문집
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    • pp.100-103
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    • 2009
  • The impermeable area on the surface of city has been increased as buildings and artificial landcover have continually been increased. Urban development has gradually decreased the green zone in downtown and alienated the city from the natural environment on outskirt area devastating the natural eco system. There arise the environmental problems peculiar to city including urban heat island phenomenon, urban flood, air pollution and urban desertification. As one of urban plans to solve such problems, green roof system is attracting attentions. The purpose of this study was to investigate the heat reduction effect according to the development of green roof system and to quantify the heat reduction effect by analyzing through simulation the heat environment before and after green roof system. For thermal environment analysis, Thermo-Render 3.0 was used that was developed by Tokyo Industrial College to simulate. The simulation showed that the heat island index before and after the development of tree-planting on rooftop changed maximum $0.86^{\circ}C$ and the surface temperature changed about $20^{\circ}C$. Only with lawn planting, heat reduction effect was great and it means that the green roof system in low-management-light-weight type is enough to see effect. The simulation identified that only lawn planting for green rooftop brought such difference and could lower the heat island index at a narrow area. It is judged that application of green roof system to wider areas might relieve urban heat island phenomenon positively.

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녹색도시 물순환 계획요소 및 수문순환 모의 (The Urban Water Cycle Planning Elements and Hydrologic Cycle Simulation for Green City)

  • 이정민;김종림
    • 토지주택연구
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    • 제3권3호
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    • pp.271-278
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    • 2012
  • 전 지구적인 기후변화와 지구 온난화에 따라 서구 선진 국가들을 중심으로 저탄소 녹색성장(green growth)이 이슈로 등장하고 있고 이 전략은 미래의 성장동력으로까지 발전되고 있다. 저탄소 사회를 달성하기 위하여 세계 각국은 교토의정서를 체결하고 온실가스배출량을 2008년부터 2012년까지 1990년도 수준의 5.2%까지 줄이도록 선언하였다. 한편 급속한 도시개발과 불투수면적의 증가는 도시의 물순환의 변화를 초래한다. 본 연구에서는 녹색도시 개념을 검토하고 기존의 연구를 바탕으로 도시 및 단지수준에 적합한 물순환 계획요소를 검토하였다. 추가적으로 본 연구에서는 SWMM5-LID 수문모형을 이용하여 시범유역에 물순환 효과를 분석하였다. 물순환 분석은 개발전, 개발후, 녹색도시계획요소적용후(LID시설 적용후)에 대한 시범유역의 도시유출연속모의를 통하여 수행되었다.

빗물 저류 시스템을 활용한 옥상 녹화의 온도 저감 효과 (The effect of Temperature Reduction of Green Roof using Rainwater Storage Tank)

  • 윤석환;김은섭;박정강;전윤호;강혜원;김상혁;김지연;강한민;함은경;이동근
    • 한국환경복원기술학회지
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    • 제24권6호
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    • pp.109-119
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    • 2021
  • Thermal environment of city is getting worse due to severe urban heat island caused by climate change and urbanization. Green roof improves the urban thermal environment and save the cooling energy in buildings. This study presented a green roof combined with a storage system that stores rain-water and supplies water through a wick and evaluated the temperature reduction effect as surface temperature and amount of evapotranspiration. For about a week, the surface temperature using a infrared thermal imager and the evapotranspiration by recording change of module weight were measured at intervals of 30 minutes from sunrise to sunset. The results show that the mean surface temperature of the green roof was 15.4 degrees lower than that of the non-green roof from 12:00 P.M. to 14:00 P.M. There was no significant difference between mean surface temperature of green roof with and without storage system immediately after rain, but more than a week after rain, there was a difference with average of 2.49 degrees and maximum of 4.72 degrees. The difference in daily amount of evapotranspiration was measured to be 1.66 times on average. As drought stress increased over time, the difference in daily amount of evapotranspiration and surface temperature between with/without storage system increased simultaneously. The results of the study show a more excellent cooling effect of green roof combined with the rainwater storage system.

Green network analysis in coastal cities using least-cost path analysis: a study of Jakarta, Indonesia

  • Kim, Jae-Eun
    • Journal of Ecology and Environment
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    • 제35권2호
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    • pp.141-147
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    • 2012
  • The rapid urbanization in developing countries is accelerating both the depletion and fragmentation of urban green space, despite the known positive effects of green spaces on the environmental conditions in cities and the quality of life of residents. Consequently, there is a need for practical tools that can support the development of networks of urban green spaces. This article presents a study that used a GIS-based least cost path (LCP) analysis to identify the best alternative for developing an urban green space network in the coastal city of Jakarta, Indonesia, which was based on the evaluation of topography and land use characteristics. Pair-wise analysis was used to reduce the sensitivity in the LCP model. The results showed that the coastal wetlands in the northern part of Jakarta and the agricultural fields in the suburban areas of Jakarta play an important role in connecting the green space network. On the other hand, some green spaces in the central part of Jakarta could not be connected by the LCP model. The method used in this study can serve as a tool to support the identification of networks of potential urban green spaces. It can also provide useful information for sustainable urban landscape planning and management in urban ecosystems. However, the inclusion of socio-economic criteria would further improve the model.

탄소저감 도시계획 시스템의 통합화 방안 도출 연구 (A study on Integrating Strategy of Low-carbon Urban Planning System)

  • 박찬호;김범석
    • Spatial Information Research
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    • 제21권2호
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    • pp.99-106
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    • 2013
  • 현대사회가 산업화 되고 고도성장을 이룩하며 자연환경이 훼손됨에 따라 기후변화 대응 및 저탄소 녹색성장을 위한 도시차원의 구체적인 실천대안의 필요성이 증대되고 있다. 국내에서 많은 저탄소도시 및 녹색도시 관련 연구가 진행 중에 있으나 대부분의 관련 연구들에서는 저탄소도시 혹은 녹색도시 구축을 위한 연구를 진행함에 있어 건축, 교통, 에너지 등 각 분야별로 연구를 진행하고 있기에 각 분야별 연구 결과들이 통합적으로 이용되지 않고 있다. 본 논문에서는 이러한 문제점을 해결하기 위하여 저탄소도시 혹은 녹색도시를 위한 시스템을 구축하는 관련 연구들의 현황을 조사하고, 각 분야별로 도출된 결과물을 통합적으로 이용할 수 있는 방안을 정의하고자 한다. 논문에서 정의된 '탄소저감 도시계획 통합시스템'의 통합 모델로서 각 개별 시스템을 분석 시 데이터 로드 등에 대한 문제로 인하여 C/S 시스템으로 개발하고, 통합 시스템에 분석된 DB를 조회/활용할 수 있도록 개발하며, 통합 시스템은 Web으로 개발하는 방향으로 결정하였다. 본 연구 결과를 바탕으로 차후 연구개발 사업들에서는 경제적이고 효율적인 통합 모델이 도출될 수 있을 것이며, 현장에서 실제로 각 개발 성과물들이 활용될 수 있을 것이다.

Merits and Demerits of the Inspection System introduced in Construction of City Planning Road: In Case of Crossing Road of the Aioiyama Green Area in Nagoya

  • Yutaka Okamura
    • Journal of the Korean Institute of Landscape Architecture International Edition
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    • 제2호
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    • pp.178-184
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    • 2004
  • The Yatomi - Aioiyama line is a city-planning road that was notified in 1957 and subsequently prepared by land readjustments. Currently, approximately 900m of road pass in the inside of the Aioiyama green area has not been constructed. The surveying briefing session for inhabitants was held in July 1992, the project was authorized by the Ministry of Land, Infrastructure and Transport in September 1993, and the project briefing session for inhabitants was held in September 1993. The site purchase has been completed. At the May 2000 briefing session, inhabitants of the area began voicing dissenting demanding the conservation of the natural environment of this green area. The inspector system serves as the third party, independent of both the administration and the inhabitants. Before finalizing the geometric line form of the road to be constructed, some surveys of animals and plants found along the walking trails carried out intensively in the northern area, which is approximately 50 ha, of the Aioiyama green area. The natural environment inspector submitted a plan for changing the geometric line form of the road decided upon by city planning, and it was approved by the city planning council. If the shelter structure or the retaining wall structure is adopted at the location where large slope faces are produced by excavation or landfill, and if the bridge structure is adopted at the place where stream-lines and walking trails intersect, it leads to a reduction of approximately $40\%$ in the areas for which change is planned. Furthermore, approximately $20\%$ of the area to be changed is restored by returning soil to the roof of the shelter.

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