• Title/Summary/Keyword: surrounding environment

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Change in the Plant Temperature of Tomato by Fogging and Airflow in Plastic Greenhouse (포그분사 및 공기유동에 의한 온실재배 토마토의 엽온 변화)

  • Nam, Sang-Woon;Kim, Young-Shik;Seo, Dong-Uk
    • Journal of Bio-Environment Control
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    • v.23 no.1
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    • pp.11-18
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    • 2014
  • To investigate the influence of surrounding environment on the plant temperature and examine the effect of plant temperature control by fogging and airflow, plant temperature of tomato, inside and outside air temperature and relative humidity, solar radiation and wind speed were measured and analyzed under various experimental conditions in plastic greenhouse with two-fluid fogging systems and air circulation fans. According to the analysis of plant temperature and the change of inside and outside air temperature in each condition, inside air temperature and plant temperature were significantly higher than outside air temperature in the control and shading condition. However, in the fogging condition, inside air temperature was lower or slightly higher than outside air temperature. It showed that plant temperature could be kept with the temperature similar to or lower than inside air temperature in fogging and airflow condition. To derive the relationship between surrounding environmental factor and plant temperature, we did multiple regression analysis. The optimum regression equation for the temperature difference between plant and air included solar radiation, wind speed and vapor pressure deficit and RMS error was $0.8^{\circ}C$. To investigate whether the fogging and airflow contribute to reduce high temperature stress of plant, photosynthetic rate of tomato leaf was measured under the experimental conditions. Photosynthetic rate was the highest when using both fogging and airflow, and then fogging, airflow and lastly the control. So, we could assume that fogging and airflow can make better effect of plant temperature control to reduce high temperature stress of plant which can increase photosynthetic rate. It showed that the temperature difference between plant and air was highly affected by surrounding environment. Also, we could estimate plant temperature by measuring the surrounding environment, and use it for environment control to reduce the high temperature stress of plant. In addition, by using fogging and airflow, we can decrease temperature difference between plant and air, increase photosynthetic rate, and make proper environment for plants. We could conclude that both fogging and airflow are effective to reduce the high temperature stress of plant.

Thermophoretic deposition of soot particles in laminar diffusion flame along a solid wall in microgravity (미소중력환경에서의 고체벽면근방 층류확산염내 매연입자의 열영동 부착)

  • Choi, Jae-Hyuk;Osamu, Fujita;Chung, Suk-Ho
    • 한국연소학회:학술대회논문집
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    • 2007.05a
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    • pp.19-24
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    • 2007
  • The deposition behavior of soot particles in a diffusion flame along a solid wall was examined experimentally by getting rid of the effect of natural convection utilizing microgravity environment. The microgravity environment was realized by using a drop tower facility. The fuel for the flame was an ethylene ($C_2H_4$) and the surrounding oxygen concentration 35% with the surrounding air velocity of $V_a$=2.5, 5, and 10 cm/s. Laser extinction method was adopted to measure the soot volume fraction distribution between the flame and burner wall. The results show that observation of soot deposition in normal flame was difficult from buoyancy and the relative position of flame and solid surface changes with time. The soot particle distribution region moves closer to the surface of the wall as the surrounding air velocity is increased. And the experiments determined the trace of the maximum soot concentration line. It was found that the distance between soot line and flame line is around 5 mm. That is, the soot particle near the flame zone tends to move away from flame zone because of thermophoretic force and to concentrate at a certain narrow area inside of the flame, finally, to adhere the solid wall.

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Design of Sajik Fountain (사직분수대 설계)

  • 김영인;김민중;김정수;홍형순;장태현
    • Journal of the Korean Institute of Landscape Architecture
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    • v.29 no.4
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    • pp.75-81
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    • 2001
  • This project provides designs for renewal of the surrounding environment related to old fountains typically located in cities. In many cities, the fountain element has bee located with a strategic position in the city. Located in the central area of Cheongju, the Sajik Fountain Fountain has significant position in the local city. However, due to changes in the surrounding area and the old-fashioned form of the fountain, it has not contributed substantially to the cityscape. Including the historical Seomoon Bridge and Moosim-Cheon(stream) as Wooam-San(mountain) setting, the surrounding environment of our planning site appear to be a locally important place. In respect to building with a broad function, landscape designers focused on the reconsideration of symbolization as landmark, of the image of Cheongju city, of recognition by removing the horizontal line and of the substantial civil´s use rate. Achieved by working with a sculptor, a new function, the main facility, is managed sculpturally and imaged in a drop of water representing clear, fresh Cheongju city. This plan introduces the image of Wooam-San, Moosim-Cheon(stream), Sangdang-SanSung(A mountain fortress) and elicit a sense of peace, symbolic of Cheongju. The significance of this project is that as the current cities are increasingly developed, small areas left alone in city are reconsidered and offered to the public as efficient, resting and active outdoor space.

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Survey and Analysis of Impact of Hebei Spirit Oil Pollution Incident on Surrounding Environment (허베이스피리트호 유류오염사고가 주변환경에 미치는 영향조사 및 분석)

  • Chung, Kwang-Yong;Lee, Seung-Hwan
    • Journal of Digital Convergence
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    • v.10 no.6
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    • pp.205-211
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    • 2012
  • According to the Hebei Spirit incident, 12,547kl of crude oil was spilled into the sea and a total of approximately 40,000 households was damaged. Also, eleven cities and counties including "Taean" were designated as a Special Disaster District by government. Large oil pollution incidents cause severe impact on the change of the surrounding environment as well as destruction of the natural environment of damaged areas. This study analyzes the impacts on the surrounding environment of damaged areas caused by Hebei Spirit oil pollution incident, focusing on the largest damaged county called Taean. Survey was performed with items which are changes in population and local economy, effects on public health, social conflicts and etc. The result of analysis can be used as an important factor to forecast the impact on a damaged area in case of future oil pollution incidents and to establish effective policy of government.

Neutron Dosimetry and Monitoring in the Radiation Environment

  • Nakamura, Takashi
    • Journal of Radiation Protection and Research
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    • v.14 no.2
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    • pp.51-62
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    • 1989
  • The high efficiency moderated-type neutron spectrometer and doseequivalent counter were developed for the measurement of low level environmental neutrons. By using these detectors, the neutron energy spectra and dose equivalent rates due to skyshine effect were measured in the environment surrounding the accelerator facilities and also the altitude variation of cosmic ray neutrons in the aircraft flying over Japan.

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Growth Environment and Management Status of Legally Protected Trees in Gwangju, Gyeonggi-do (경기도 광주시 보호수의 생육환경 및 관리실태 조사 연구)

  • Jun, HyungSoon
    • Journal of Environmental Science International
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    • v.29 no.4
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    • pp.371-382
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    • 2020
  • This study was conducted to suggest a management plan for legally protected trees in Gwangju, Gyeonggi-do by examining their distribution and growth. A literature review and field survey of these trees were conducted to derive problems and usage plans, with a number of key results. Among the legally protected trees (77 species in total) in 74 locations within Gwangju, Gyeonggi-do, the growth status of 74 species (96.10%) was above average, indicating that most legally protected trees were growing without any issues. Despite the results, analysis of the function of these legally protected trees indicated that there was low diversity and utilization of these trees as only trees in 33.77% were used as resting places or pavilions while those in 66.23% were used for landscaping or other purposes. It was assumed that these legally protected trees and the areas surrounding them in Gwangju, Gyeonggi-do will be used as community spaces if the environment is improved. This includes converting these areas into small parks or resting places for residents. In addition, further research should be carried out to maintain good growth conditions for these legally protected trees in general and to explore various plans that allow utilization of the surrounding natural ecosystem, human environment, and cultural elements in order to enhance the quality of the region and improve it as a living space for residents.

Recent Research Trends of Flexible Piezoelectric Nanofibers for Energy Conversion Materials (에너지 변환 소재용 플렉서블 압전 나노섬유 연구 개발 동향)

  • Ji, Sang Hyun;Yun, Ji Sun
    • Ceramist
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    • v.22 no.2
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    • pp.122-132
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    • 2019
  • Wearable electronic devices with batteries must be lightweight, flexible and highly durable. Most importantly, the battery should be able to self-generate to operate the devices without having to be too frequently charged externally. An eco-friendly energy harvesting technology from various sources, such as solar energy, electromagnetic energy and wind energy, has been developed for a self-charging flexible battery. Although the energy harvesting from such sources are often unstable according to the surrounding environment, the energy harvesting from body movements and vibrations has been less affected by the surrounding environment. In this regard, flexible piezoelectric modules are the most attractive solution for this issue, because they convert mechanical energy to electrical energy and harvest energy from the human body motions. Among the various flexible piezoelectric modules, piezoelectric nanofibers have advantages when used as an energy harvester in wearable devices, due to their simple manufacturing process with good applicability to polymers and ceramics. This review focused on diverse flexible piezoelectric nanofibers and discusses their applications as various energy harvesting systems.