• Title, Summary, Keyword: greenhouse

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The analysis of students' ideas about the greenhouse effect (온실효과에 대한 학생들의 개념 분석)

  • Je, Kwi-Youn;An, Hui-Soo
    • Journal of The Korean Association For Science Education
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    • v.19 no.4
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    • pp.585-594
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    • 1999
  • The purpose of this study is to examine the concept of Greenhouse Effect as understood by middle school high school university students using a closed-form questionnaire. Based on results of the questionnaire which was administered to 619, the extent to which alternative concepts were held was quantified and compared the difference of various group based on grade level. gender, text and major. Also, subjects were divided into two groups, one is middle school students and the other is high school university students and common themes within conceptual framework of each group were identified by factor analysis. The result showed that students confused Greenhouse Effect with ozone layer depletion in stratosphere and linked familiar contamination around everyday life. acid rain. radioactive contamination, nuclear arsenal to Greenhouse Effect. These trends were more appreciable in female than male, biology major than any other major and text did not make any significant difference. In addition, the result of factor analysis showed that two groups linked familiar contamination around everyday life to Greenhouse Effect and high school university students understand the consequences of an increase in the Greenhouse Effect more systematically than middle school student, perceived the relation between the origin of an increase in the Greenhouse Effect and human activity but confused Greenhouse Effect with ozone layer depletion in stratosphere.

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Korean Fifteen-Year-Olds' Alternative Conceptions on the Greenhouse Effect Revealed in PISA Test Results (PISA 검사 결과에서 드러난 만15세 한국 학생들의 온실효과에 대한 대안적 개념)

  • Kwak, Young-Sun
    • Journal of The Korean Association For Science Education
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    • v.24 no.3
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    • pp.668-674
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    • 2004
  • This study investigated Korean fifteen-year-olds' (mis)conceptions on the greenhouse effect based on the PISA results. Based on previous studies on students' ideas about the greenhouse effect, Korean students'understanding of the natural factors and human-induced factors of the greenhouse effect were analyzed. Students' misconceptions about causes of the greenhouse effect were also examined. In addition to CO2, Students mentioned CFCs, atmospheric pollution, water vapor and methane as greenhouse gases. Many students indicated that the greenhouse effect and ozone depletion have a causal relationship. Teaching implications of the misconceptions were also discussed.

Investigation into Methods for reducing Greenhouse Gas Emission in Paper Industry with Development of Greenhouse Gas Inventory (온실가스 인벤토리 구축을 통한 제지산업에서 온실가스 절감 방법론 조사)

  • Kim, Dong-Seop;Sung, Yong-Joo;Lee, Joon-Woo;Kim, Se-Bin;Park, Gwan-Soo
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.44 no.2
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    • pp.49-57
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    • 2012
  • The reduction of greenhouse gas emission currently becomes more urgent task for Korean Industries, especially for the paper industries because of the new regulation based on the low carbon-green growth law. In order to reduce effectively the greenhouse gas emission, the development of greenhouse gas emission inventory has been widely considered as one of the basic processes and has been applied to many industries. In this study, the fundamental schemes and the cases of greenhouse gas inventories were investigated. Especially, the major considering units for paper industries were suggested to develope greenhouse emission inventory of paper industry.

Effect of Polycarbonate Covering Sheet on Greenhouse Indoor Environments and Growth Behavior of Cherry Tomatoes

  • Choi, Kyung Yun;Kim, Soo Bok;Bae, Seokhu;Yoon, Jeong-Hwan;Yun, Ju-Ho;Kim, Namil
    • Elastomers and Composites
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    • v.55 no.2
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    • pp.114-119
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    • 2020
  • The effect of a greenhouse-covering material on its indoor environment and on the characteristics of cherry tomatoes grown in it was investigated. The conventional polyethylene (PE) film on the greenhouse roof was replaced by a polycarbonate (PC) sheet, while maintaining the main structural frame intact. Color changes and the formation of water droplets on the PC surface were avoided by applying coextrusion and coating layers. When compared to the PE greenhouse, the PC greenhouse enabled increased light transmittance and thus a higher indoor temperature during both summer and winter. The thermal insulating property of the PC sheet effectively reduced the heating loss by approximately 55% during winter. The cherry tomatoes grown in the PC greenhouse exhibited superior fruit characteristics in terms of size, weight, and sugar content. The total amount of cherry tomatoes produced per unit area (1,000 ㎡) in the PC greenhouse was found to be greater by approximately 19% compared to that in the PE greenhouse.

Design of Energy Model of Greenhouse Including Plant and Estimation of Heating and Cooling Loads for a Multi-Span Plastic-Film Greenhouse by Building Energy Simulation (건물에너지시뮬레이션을 활용한 연동형 온실 및 작물에너지모델 설계 및 이의 냉·난방부하 산정)

  • Lee, Seung-No;Park, Se-Jun;Lee, In-Bok;Ha, Tae-Hwan;Kwon, Kyeong-Seok;Kim, Rack-Woo;Yeo, Uk-Hyeon;Lee, Sang-Yeon
    • Protected Horticulture and Plant Factory
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    • v.25 no.2
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    • pp.123-132
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    • 2016
  • The importance of energy saving technology for managing greenhouse was recently highlighted. For practical use of energy in greenhouse, it is necessary to simulate energy flow precisely and estimate heating/cooling loads of greenhouse. So the main purpose of this study was to develope and to validate greenhouse energy model and to estimate annual/maximum energy loads using Building Energy Simulation (BES). Field experiments were carried out in a multi-span plastic-film greenhouse in Jeju Island ($33.2^{\circ}N$, $126.3^{\circ}E$) for 2 months. To develop energy model of the greenhouse, a set of sensors was used to measure the greenhouse microclimate such as air temperature, humidity, leaf temperature, solar radiation, carbon dioxide concentration and so on. Moreover, characteristic length of plant leaf, leaf area index and diffuse non-interceptance were utilized to calculate sensible and latent heat exchange of plant. The internal temperature of greenhouse was compared to validate the greenhouse energy model. Developed model provided a good estimation for the internal temperature throughout the experiments period (coefficients of determination > 0.85, index of agreement > 0.92). After the model validation, we used last 10 years weather data to calculate energy loads of greenhouse according to growth stage of greenhouse crop. The tendency of heating/cooling loads change was depends on external weather condition and optimal temperature for growing crops at each stage. In addition, maximum heating/cooling loads of reference greenhouse were estimated to 644,014 and $756,456kJ{\cdot}hr^{-1}$, respectively.

A Study on the Landscape Preference Analysis of Facility Horticulture Complex in Rural Area - Focus on Korea, Netherlands, Japan - (농촌지역 시설원예단지 경관선호도 분석 연구 - 한국, 네덜란드, 일본을 대상으로 -)

  • Son, Jinkwan;Kong, Minjae;Shin, Minji;Shin, Jihoon;Kang, Donghyeon;Yun, Sungwook;Lee, Siyoung
    • Journal of Korean Society of Rural Planning
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    • v.23 no.4
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    • pp.27-38
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    • 2017
  • Humans are provided with a wide range of public benefits from ecosystems and agricultural ecosystems. But the establishment of the horticulture complex is a space that hampers the public ecosystem. Therefore, we have evaluated the creating landscape function of the horticulture complex and found improvement. A total of 20 landscape slides were used for the study. Korea-paddy field, Korea-vinyl greenhouse, Korea-glass greenhouse, Japan-vinyl greenhouse and Netherlands-glass greenhouse were selected as 4 slides. The evaluation used the AHP method and 10 adjectives Likert which compares 20 landscape slides. Four Korea-paddy fields were rated highly positive images. All 10 adjectives can be selected as representative images of production scenes. In most adjectives, four scenes of KVG1, KVG2, KVG3 and KVG4, which are the Korea-greenhouse scenes, were evaluated as negative images. Netherlands and Korea-glass greenhouse scenes and Japan-vinyl greenhouse scenes were generally positive images. In conclusion, it is confirmed that glass greenhouse scenery is higher than vinyl greenhouse scenery. And Japan and Netherlands scenery are higher and better than Korea. Therefore, JVG1 in Japan and NGG3 in the Netherlands were proposed to be set as landscape improvement targets.

Estimation of Wind Pressure Coefficients on Even-Span Greenhouse Built in Reclaimed Land according to Roof Slop using Wind Tunnel (풍동을 이용한 간척지 내 양지붕형 온실의 지붕 경사에 따른 풍압계수 평가)

  • Kim, Rack-Woo;Kim, Dong-Woo;Ryu, Ki-Cheol;Kwon, Kyeong-Seok;Lee, In-Bok
    • Protected Horticulture and Plant Factory
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    • v.23 no.4
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    • pp.269-280
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    • 2014
  • To cope with increasing of vegetables and flowers consumptions, horticulture facilities have been modernized. Korea government recently announced construction plan of new greenhouse complex at reclaimed land. However wind characteristics of reclaimed land is totally different from those of inland, wind pressure on greenhouse built in reclaimed land should be carefully evaluated to secure structural safety on the greenhouse. In this study, as a first step, wind pressure coefficient and local wind pressure coefficient on even-span greenhouse were measured using wind tunnel test. ESDU was adopted to realize wind characteristics of reclaimed land such as wind and turbulence profiles. From the wind tunnel test, when wind direction was 0 degree, it was concluded that KBC2009 standard underestimated scale of wind pressure coefficients at roof area of greenhouse whereas NEN-EN2002 standard underestimated those at every surface of greenhouse. When wind direction was 90 degree, both standards did not well reflect the characteristics of wind pressure distribution. From the analysis of local wind pressure coefficients according to wind direction conditions, design of covering, glazing bar of greenhouse where large effects of the local wind pressure were estimated should be well established. Wind pressure coefficients and local wind pressure coefficients according to parts of the greenhouse were finally suggested and these results could be practically used for suggesting new design standards of greenhouse.

Spatial, Vertical, and Temporal Variability of Ambient Environments in Strawberry and Tomato Greenhouses in Winter

  • Ryu, Myong-Jin;Ryu, Dong-Ki;Chung, Sun-Ok;Hur, Yun-Kun;Hur, Seung-Oh;Hong, Soon-Jung;Sung, Je-Hoon;Kim, Hak-Hun
    • Journal of Biosystems Engineering
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    • v.39 no.1
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    • pp.47-56
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    • 2014
  • Purpose: In protected crop production facilities such as greenhouse and plant factory, farmers should be present and/or visit frequently to the production site for maintaining optimum environmental conditions and better production, which is time and labor consuming. Monitoring of environmental condition is highly important for optimum control of the conditions, and the condition is not uniform within the facility. Objectives of the paper were to investigate spatial and vertical variability in ambient environmental variables and to provide useful information for sensing and control of the environments. Methods: Experiments were conducted in a strawberry-growing greenhouse (greenhouse 1) and a cherry tomato-growing greenhouse (greenhouse 2). Selected ambient environmental variables for experiment in greenhouse 1 were air temperature and humidity, and in greenhouse 2, they were air temperature, humidity, PPFD (Photosynthetic Photon Flux Density), and $CO_2$ concentration. Results: Considerable spatial, vertical, and temporal variability of the ambient environments were observed. In greenhouse 1, overall temperature increased from 12:00 to 14:00 and increased after that, while RH increased continuously during the experiments. Differences between the maximum and minimum temperature and RH values were greater when one of the side windows were open than those when both of the windows were closed. The location and height of the maximum and minimum measurements were also different. In greenhouse 2, differences between the maximum and minimum air temperatures at noon and sunset were greater when both windows were open. The maximum PPFD were observed at a 3-m height, close to the lighting source, and $CO_2$ concentration in the crop growing regions. Conclusions: In this study, spatial, vertical, and temporal variability of ambient crop growing conditions in greenhouses was evaluated. And also the variability was affected by operation conditions such as window opening and heating. Results of the study would provide information for optimum monitoring and control of ambient greenhouse environments.

Development of Greenhouse Gas Emission Factors from Sewage Sludge Incinerator (하수슬러지 소각장의 온실가스 배출계수 개발)

  • Kim, Seungjin;Kang, Seongmin;Kang, Soyoung;Lee, Jeongwoo;Sa, Jae-Hwan;Park, Seong-Jin;Jeon, Eui-Chan
    • Journal of Climate Change Research
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    • v.5 no.3
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    • pp.209-218
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    • 2014
  • In this study, the researchers have developed the greenhouse gas emission coefficients targeted at sewage sludge incineration plants that treat sewage sludge by incineration. Among the gases emitted from the sewage sludge incineration plants, the greenhouse gases showed concentrations of 6.84% for $CO_2$, 4.51 ppm for $CH_4$, and 86.34 ppm for $N_2O$; calculated into greenhouse gas emission coefficients, these gave $276.06kg\;CO_2/ton$, $0.0066kg\;CH_4/ton$, and $0.35kg\;N_2O/ton$. As the result of calculating the greenhouse gas emission quantity in sewage sludge incineration plants using the greenhouse gas emission coefficients, the gross greenhouse gas emission was $84.63ton\;CO_2\;eq./day$, and the net emission was $23.90ton\;CO_2\;eq./day$; this was $37.52ton\;CO_2\;eq./day$ less than the net greenhouse gas emission that was calculated using the standard values of IPCC, which was $61.42ton\;CO_2\;eq./day$. This difference is probably because unlike the standard values of IPCC, the greenhouse gas emission coefficients of this study reflected the special properties of subject facilities. Thus, it is thought that emission coefficient research on the facilities that deviated from the standard values of IPCC should continue to achieve the development of national greenhouse gas coefficient that reflects the special properties of Korea.

Study on the Latent Heat Storage of Solar Energy for Greenhouse Heating (Greenhouse 보온(保溫)을 위한 태양(太陽)에너지 잠열축열(潛熱蓄熱) 연구(硏究))

  • Song, H.K.;Tyu, Y.S.
    • Journal of Biosystems Engineering
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    • v.16 no.4
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    • pp.399-407
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    • 1991
  • In Korea, the cultivation area under the plastic greenhouse was 1,746 ha in 1975, and 36,656 ha in 1989, it shows that the greenhouse cultivation area was increased by 21 times during last 14 years. The greenhouse cultivation area of 90~93% has been kept warm with double layers of plastic film and thermal curtain knitted with rice straw, and the rest area of 7~10% has been heated by fossil fuel energy. The use of rice straw thermal curtain is inconvenient to put it on and off, on the other hand the use of fossil fuel heating system results in the increase of production cost. To solve these problems, at first the heating load and the storable solar energy in greenhouse during the winter season were predicted to design solar utilization system, secondly a solar thermal storage system filled with latent heat storage materials was developed in this study. And then finally the thermal performance of greenhouse-solar energy storage system was analyzed theoretically and experimentally.

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