• Title/Summary/Keyword: 온실 구조

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Life Cycle Assessment of Timber Arch-Truss Bridge by Using Domestic Pinus rigida Glued-Laminated Timber (리기다소나무 구조용 집성재를 활용한 아치 트러스 목조교량의 전과정평가)

  • Son, Whi-Lim;Park, Joo-Saeng;Kim, Kwang-Mo
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.1
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    • pp.1-12
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    • 2014
  • This study carried out life cycle assessment for evaluating environmental impacts of timber Arch-Truss bridge by using domestic Pinus rigida Miller glued-laminated timber throughout life cycle such as extraction, manufacturing, transportation, construction, use, dismantlement, transportation of waste, disposal and recycling. The life cycle GHG (GreenHouse Gas) emissions of the target bridge are 192.56 ton $CO_2$ eq. in 50 years. Especially, the life cycle GHG emissions of concrete used in the target bridge are 82.84 ton $CO_2$ eq. which accounts for 53.02% of the GWP (Global Warming Potential) in extraction and manufacturing stages. The target bridge is constructed of $116.57m^3$ of domestic Pinus rigida Miller glued-laminated timber and used timber has stored 104.72 ton $CO_2$. If an effect of carbon storage in timber is applied to the total GHG emissions of the target bridge, the GHG emissions can be reduced by 54.38%. In the case of substitution effect, if domestic Pinus rigida Miller glued-laminated timber replaces steel manufactures used in other bridge which has the same structure and life span as the target bridge, the GHG emissions in extraction and manufacturing stages can be reduced by 10.26% to 23.91%.

Analysis of Structural Safety of the Welded Pipe Columns Adopted in Paprika Greenhouse (파프리카 재배용 온실에서 용접 파이프 기둥재의 구조적 안전성 검토)

  • Suh, Won-Myung;Choi, Man-Kwon;Im, Jae-Un;Kwon, Sun-Ju;Kim, Hyeon-Tae;Kim, Young-Ju;Yoon, Yong-Cheol
    • Journal of agriculture & life science
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    • v.45 no.2
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    • pp.125-133
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    • 2011
  • This study was conducted on greenhouses whose side heights had been raised after the columns of 1-2W basic type greenhouses had been cut and welding with the same-sized pipes. When the wind load or snow load affects restructured pipe greenhouse like this, those parts will be structurally unsafe. To examine this, the bending strength of welded columns were measured through four stages and compared with the pipes in their original condition. Results are as follows. In the case of a bending test on welded joints about steel pipes used for greenhouses, satisfactory results couldn't be drawn because sections of both ends and the loading parts couldn't endure loads and sank regardless of loading methods. Partial problems could be solved by inserting inside pipe(steel bar) at the sections and the loading parts, but it was necessary to devise more satisfactory bending test methods. The strength of welded joints wasn't much different compared with original conditions and demonstrated only slight differences according to the sample production conditions. However, significant incompleteness in the welding process was expected to cause a decisive loss in strength. On the assumption that there were no problems in the welding process or with regard to the inclination of sub materials for columns after connection, it was deemed reasonable to assume that the strength of welded pipes was about 84~90% of the strength of the pipes in their original condition. Considering mid- and long-term strength decline following the onset of rust at joints or welding sections, structural changes in the main sub materials that are used for greenhouses at farmhouses have to be avoided to ensure structural safety, unless these changes are inevitable.

Structure and Experimental Results of Automatic Insulation Greenhouse (자동단열온실의 구조 및 운전특성)

  • 이종원;이석건;이현우
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 1994.05a
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    • pp.88-91
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    • 1994
  • 최근 국내에서도 시설원예가 급격하게 보급되고 있는 실정이다. 하지만, 시설원예가 에너지 소비형의 농경방식이라 지적되고 있는바 에너지절약형 온실의 개발이 필요할 것으로 판단되어, 본 실험실에서는 본 연구와 관련하여 비닐하우스의 벽체를 이중으로 하여 이중벽사이에 단열입자를 송풍기의 케이싱내로 직접 통하게하는 직송방식으로 충전ㆍ회수하는 실험을 실시한 바가 있으며, 그 결과 외기온의 평균이 -4.9$^{\circ}C$인 겨울철 야간에 입자를 충전한 이중비닐 하우스의 내부온도는 평균 9.8$^{\circ}C$로 단열성이 우수함을 알 수 있었다.(중략)

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The Temperature and Flow to Affect Removal Efficiency of Carbon Dioxide in a Pilot Plant (Pilot Plant를 이용한 이산화탄소 흡수분리에 있어 온도와 유량 효과)

  • 김준한;심재구;송광철;엄희문
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.11a
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    • pp.522-523
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    • 2003
  • 1992년 리우에서 결의된 기후변화협약은 전 인류의 공통된 그러나, 차별화된 온실가스감축 노력을 약속한 국제 환경협약인 동시에 국가경제활동을 좌우할 경제협약 나아가 기술협약의 성격을 지니고 있다. 에너지 이용과 밀접한 관계를 가지는 지구 온난화문제는 최근 미국의 교토의정서 탈퇴 선언으로 인해 기본구조가 흔들리는 위기를 맞기도 하였지만, 유럽연합을 비롯한 대부분의 국가는 지구환경 보존이라는 명분에 따라 정치적 합의를 도출함에 따라 우리나라에서도 지구 온난화 방지를 위한 온실 기체 저감 기술의 개발이 필요한 실정이다.(중략)

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Decomposition Analysis of Energy Consumption and GHG Emissions by Industry Classification for Korea's GHG Reduction Targets (감축목표 업종 분류체계에 따른 산업부문의 에너지 소비 및 온실가스 배출 요인 분해 분석)

  • Park, Nyun-Bae;Shim, SungHee
    • Environmental and Resource Economics Review
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    • v.24 no.1
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    • pp.189-224
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    • 2015
  • To meet sectoral emission target by 2020 and prepare for the emission trading scheme from 2015, decomposition analysis of energy consumption and GHG emission is required by 18 subsectors in industry sector where emission targets are established. Log Mean Divisia Index decomposition method was used to analyze factors' effects on energy and emission in the industry sector and by 18 subsectors from 2004 to 2011. Industrial energy consumption was increased due to the production effect and energy intensity effect. However structure effect contributes to the decrease of energy consumption. In terms of emissions (including indirect emission due to electricity consumption) in the industry sector, only structure effect contributed to the emission reduction. Factors' effects by subsectors were different. Cement industry, which is included at Nonmetal shows different results from those of Nonmetal industry and machinery industry, which is a subsector of Fabricated Metal, was also similar. In this regard, we should not apply the policy implications from decomposition analysis of aggregated industry such as Nonmetal or Fabricated Metal to its subsectors uniformly and develop a differentiated policy for each subsector industry.

Ultrastructure of Appendages of the Greenhouse Whitefly, Trialeurodes vaporarium, with Scanning Electron Microscope (주사전자현미경을 이용한 온실가루이(Trialeurodes vaporarium) 성충 부속지의 외부 미세구조 관찰)

  • Seo, Mi-Ja;Kim, Gi-Duck;Kim, Nam-Sung;Park, Soo-Jin;Chae, Soon-Yong;Youn, Young-Nam
    • Korean Journal of Agricultural Science
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    • v.26 no.2
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    • pp.13-18
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    • 1999
  • External morphology characteristics of the greenhouse whitefly, Trialeurodes vaporarium were investigated by scanning electron microscopy. The antennae of the greenhouse whitefly was 6 segments. rod-shape, and 0.3mm length. On the 6th segment, there were many sensilla for searching host-plant as olfactory receptor. The mouthpart of the greenhouse whitefly was a piercing-sucing type, then its stylet was well developed for piercing plant leaf tissue. Claw of the foreleg was a 3-way hook shape including paranychium for attaching plant surface to pierce and lay egg.

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Analysis and Reinforcing Method of Greenhouse Frame for Reducing Heavy Snow Damage (단동온실의 설해 경감을 위한 해석 및 보강방법연구)

  • Park, Soon-Eung;Lee, Jong-Won;Lee, Suk-Gun;Choi, Jae-Hyouk
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.4
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    • pp.1-7
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    • 2010
  • Recently, the damage of the farmhouse has been increased due to frequent collapsing accidents of the pipe greenhouse caused by the heavy snow load derived from unusual weather phenomena. However, the study about it is rare and tenuous so that the damage is happened repeatedly. Although there are a few ways to improve the greenhouse such as increasing section, decreasing the distance between rafters in order to avoid the collapsing accidents, those ways have some shortcomings like cost and frame ratio increase, etc. Therefore, this study performed the large displacement analysis considering geometric non-linearity on each load level with respect to many kind of reinforcement methods and analyzed combined strength ratio and stress so as to search the ways, which enhance the structural stability of greenhouse and minimize the frame ratio increase. As a result, this paper is aimed at suggesting the optimal reinforcement method model.

The Economic and Environmental Impact of the Small Hydropower Development in Korea: A CGE Analysis (소수력 발전 확대의 경제.환경적 효과: 연산일반균형모형 분석)

  • Kim, Jae-Joon;Park, Sung-Je
    • Proceedings of the Korea Water Resources Association Conference
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    • 2011.05a
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    • pp.106-106
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    • 2011
  • 소수력은 온실가스 배출량이 적은 친환경 청정에너지원이면서 지역의 분산전원에 기여할 수 있는 유용한 자원으로 평가되고 있다. 이러한 여건은 소수력발전 사업이 전력의 smart grid 구축 효과로 인해 가장 큰 효율성을 달성할 수 있을 것으로 기대된다. 국내 소수력발전은 1500Mw의 부존량을 가진 것으로 평가되고 있으나 계절적 편중으로 인한 가동률 부족, 경제성 부족 등으로 활발한 보급이 이루어지지 않고 있다. 특히 신재생에너지 확대 전략에도 불구하고 지원금 등 경제적 인센티브 부족으로 인해 민간부문의 참여는 상당히 저조하다. 그럼에도 불구하고 수력에너지는 환경친화적이고 잠재성이 큰 신재생에너지로 온실가스 저감과 에너지 확보에 기여할 수 있다. 특히 수력에너지는 민간투자의 어려움이 존재하므로 정부의 장기적인 기술개발투자 및 효율성 확대 정책이 중요하다. 본 연구에서는 소수력 확대의 경제 환경적 효과를 평가해보기 위해 연산일반균형모형 (CGE :Computable General Equilibrium Model)을 구축한다. 본 연구는 다음과 같이 수행되었다. 첫째, 수력발전부문과 수도사업을 구분하고 사회회계행렬을 작성하였으며, 전력부문에서 수력발전을 포함한 다단계 생산구조를 가정하였다. 둘째, 일반균형모형 방정식 체계를 작성하고 모형의 파라미터 추정 등 보정(Calibration) 작업을 수행하였다. 셋째, 국가 중기 온실가스저감 시나리오를 적용한 전망을 수행하고 소수력 확대(투자지원) 시나리오를 구축한다. 본 연구는 저감수단으로 탄소세를 부과하였다. 끝으로, 소수력 발전 보급 확대의 경제적, 환경적 파급효과를 계산하였다. 분석결과, 소수력 발전 잠재 성장을 반영한 수력에너지 비중은 약 2020년에 약 4.5% 까지 증가하는 것으로 나타났다. 이로 인한 온실가스 저감 기여분은 약 3%에 이르는 것으로 계산 되었다. 또한 수도사업과 비에너지 제조업의 산업비중은 증가하였다. 이러한 결과는 소수력 발전 확대가 화석연료 대체를 통한 지속가능한 에너지 수요에 기여하고 지역개발과 물산업 발전 등 경제적 파급효과 등을 유발할 수 있음을 시사한다. 또한 본 연구에서 고려하지 못한 소수력 기술 개발은 에너지 대체 촉진으로 인한 온실가스 저감과 녹색성장에 기여할 것이다.

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