• 한국대기환경학회지
• /
• 제22권5호
• /
• pp.661-678
• /
• 2006

Products developed in this research is a software which can transfer the type of shape(.shp) into the type of ascii using the land cover data and the topography data in the metropolitan area of Seoul. In addition, it can calculate the $CO_2$ flux according to distribution of plants within the land cover data. The $CO_2$ flux is calculated by the experimental equation which is compose of the meteorological parameters such as the solar radiation and the air temperature. The net flux was shown in about $-19ton/km^2$ by removing $CO_2$ through the photosynthesis during daytime, and in 2 ton/km2 by producing it through the respiration during nighttime on 10 August 2004, the maximum day of air temperature during the period of 3yr(2001 to 2004), in the metropolitan area of Seoul. Spatial distribution of the air temperature and the wind field is simulated by substituting the middle classification of the land cover map data, upgraded by the Korean Ministry of Environment(KME), for the land-use data of the United States Geological Survey(USGS) within the Meteorological Mesoscale Model Version 5(MM5) on 10 August 2006 in the metropolitan area of Seoul. Difference of the air temperature between both data was shown in the maximum range of $-2^{\circ}C\;to\;2.9^{\circ}C$, and the air temperature due to the land use data of KME was higher than that of USGS in average $0.4^{\circ}C$. Also, those of wind vectors were meanly lower than that of USGS in daytime and nighttime. Furthermore, the hourly time series of Volatile Organic Components(VOCs) is calculated by using the Biosphere Emission and Interaction System Version 2(BEIS2) including the new land cover data and the meteorological parameters such as the air temperature and so]ar insolation. It is possible to calculate the concentration of ozone due to the biogenic emission of VOCs.

• 원예과학기술지
• /
• 제30권6호
• /
• pp.725-733
• /
• 2012

'감홍' 사과의 수확후 1-MCP 처리, CA 저장 및 유통온도가 모의 수출과정 중 품질유지에 미치는 효과를 분석하였다. 사과는 장기저장에 적합한 성숙도에서 수확하여 $1{\mu}L{\cdot}L^{-1}$ 농도의 1-MCP 처리 후 $0^{\circ}C$ 저온(air)과 $O_2$ 1.5kPa + $CO_2$ 2.5kPa CA 환경에서 각각 6개월간 저장하였다. 저장 후 모의 수출과정은 $0^{\circ}C$에서 2주간의 해상 운송 모의 과정을 거쳤으며 현지 유통과정은 저온($7^{\circ}C$) 과 상온($18-22^{\circ}C$)에서 7일로 설정하였다. $20^{\circ}C$ 온도 평형 후 측정한 저장 직후 및 모의 운송 후 호흡속도와 에틸렌 발생률은 1-MCP 처리와 CA 저장 사과에서 유의적으로 낮았고 호흡속도의 경우 CA 저장의 효과가 보다 뚜렷하였다. 모의 수출과정 후 당도는 1-MCP 처리에서 산함량은 1-MCP 및 CA 저장 사과에서 뚜렷하게 높았다. 1-MCP 처리와 CA 저장은 모든 시점에서 과육 경도 및 조직감 유지에 뚜렷한 효과를 보였으며, 조사 시점에 따라 상가효과가 있는 것으로 분석되었다. 현지에서의 저온유통은 과육 경도 유지에 효과적이었던 반면, 당도나 산함량에는 유의적인 영향을 미치지 않았다. 본 실험결과를 종합해보면, 수출을 목적으로 하는 '감홍' 사과의 저장 한계기간은 무처리 사과의 저온저장 시 4개월 이내, 1-MCP 처리 후 CA 저장 시에는 6개월 이상까지 가능한 것으로 나타나, 국내 저장기간과 현지 유통기간에 따라 차별화된 수확후관리기술 프로그램이 적용되어야 할 것으로 판단되었다.

• 한국작물학회지
• /
• 제43권2호
• /
• pp.77-82
• /
• 1998

Aerenchyma development in rice (Oryza sativa L.) roots is quite important for adaptation to waterlogged or reduced soil conditions. Anatomical observations were carried out to clarify the development of schizogenous and lysigenous aerenchyma in elongating crown roots of rice. The crown roots of 3rd and 4th phytomer were taken from rice plants of the 8th leaf stage grown by hydroponic culture. The schizogenous intercellular spaces in the cortex of crown root tip were observed using a light microscope with semi ultra-thin sections and the lysigenous aerenchyma in mature tissue of crown root were observed using a cryo scanning electron microscope (cryo-SEM) with freezing fracture method. The schizogenous intercellular spaces in the root tip exist obviously in the middle portion of cortical cell layers close to the root-root cap junction, but not in root cap, stele and outer cell layers of cortex. The air spaces were formed at the junction of four neighbouring cells of inner cortex in the transverse sections, and between longitudinal cell layer connected along the root axis. Although many of those spaces were filled with liquid, some spaces seem to exist as air spaces. The lysigenous aerenchyma in the cortex, which hardly filled with liquid, emerged at 3-4 cm segment from the root tip and increased toward the basal region of root axis. The developing process of lysigenous aerenchyma was primarily separation of a radial row of cells caused by the shrinking and collapsing of cortical cells and then formation of septa along the radial cell rows by the fusion of cell wall with each other. These results suggest that the schizogenous and lysigenous aerenchyma playa role as a passage for the movement of oxygen into the root tip region where oxygen is required for respiration.

• 한국안전학회지
• /
• 제15권1호
• /
• pp.72-79
• /
• 2000

In recent, occupational diseases in harmful working places become a social issue. It is the well-known fact that a respiration in polluted working places exert a serious effect on health of workers. Accordingly, the cutting off contaminants air originally is the best way to improve working environments. In these cases, ventilation systems should be essentially installed to dilute or exhaust the contaminated indoor air. In this study, we investigated the characteristics of ventilation system of the noxious gas in working indoor places with natural ventilation by using COMET. The numerical simulations were carried out the natural ventilation with two phase(air, dust). For turbulent flow, Reynolds stresses were closed by the standard $\kappa$-$\varepsilon$ model. The results are as follows ; 1) In the natural exhaust in the working place, the flows of the central region have a more rapid velocity vector than the right and left one. 2) Numerical results show that the distribution of contaminants concentration have greater influence on convection than the case of diffusion by government of velocity vectors. 3) To observe the velocity variation with distance, three location of distance are considered. As results, it shows that the velocity are 0.075(m/s) at y=5(m), 10(m) and mean concentration are raised 10.6% at y=5(m), 10(m). 4) We have presented the useful data for the adequate counterplan in the harmful working places by carrying out the various investigation of the natural ventilation.

• Journal of Ginseng Research
• /
• 제4권1호
• /
• pp.104-120
• /
• 1980

The effects of temperature on transpiration, chlorophyll content, frequency and aperture of stomata, and leaf temperature of Panax ginseng were reviewed. Temperature changes of soil and air under spade roof were also reviewed. Growth responses of responses of ginseng plant at various temperature were assessed in relation to suseptibillity of ginseng plants. Reasonable management of ginseng fields was suggested based on the response of ginseng to various temperatures. Stomata frequency may be increased under high temperature during leaf$.$growing stage. Stomata aperture increased by high temperature but the increase of both frequency and aperture appears not enough for transpiration to overcome high temperature encountered during summer in most fields. Serial high temperature disorder, i.e high leaf temperature, chlorophyll loss, inhibition of photosynthesis, increased respiration and wilting might be alleviated by high humidity and abundant water supply to leaf. High air temperature which limits light transmission rate inside the shade roof, induces high soil temperature(optimum soil temperature 16∼18$^{\circ}C$) and both(especially the latter) are the principal factors to increase alternaria blight, anthracnose, early leaf fall, root rot and high missing rate of plant resulting in poor yield. High temperature disorder was lessen by abundant soil water(optimum 17∼21%) and could be decreased by lowering the content of availability of phosphorus and nitrogen in soil consequently resulting in less activity of microorganisms. Repeated plowing of fields during preparation seems to be effective for sterilization of pathogenic microoganisms by high soil temperature only on surface of soils. Low temperature damage appeared at thowing of soils and emergence stage of ginseng but reports were limited. Most limiting factor of yield appeared as physiological disorder and high pathogen activity due to high temperature during summer(about three months).

• 한국약용작물학회지
• /
• 제25권6호
• /
• pp.397-403
• /
• 2017

Background: This study was aimed at evaluating the growth, yield, and carbohydrate content in the whole Allium hookeri plant with shading treatment in hot summer. Methods and Results: Different shading rate, including 0 (control), 35 or 55%, was employed from the June $21^{st}$ to August $31^{st}$. Daily average air and soil temperature, which were approximately $2.5^{\circ}C$ and $3.8^{\circ}C$ lower, respectively, were observed with both 35% and 55% treatments in July and August, with no significant difference in daily maximum air temperature. Dry weights were high, approximately 40% and 48% for the shoot and 20% and 12% for the root, with the 35% and 55% treatments, respectively, 8 weeks after shading. Division number was increased by 13% and 19.8% with the 35% and 55% treatments, respectively. The mortality rates of 150 plants were 9.1%, 4.0%, and 1.3% with the 0 (control), 35% and 55% treatments, respectively. At 4 weeks after shading, the highest and lowest sucrose levels in both shoot and root were observed with the 35% and 55% treatments, respectively. At 8 weeks after shading, there was no significant difference in the sucrose content in the shoot among the treatments. Conclusions: The highest plant growth rate and yield with the 55% treatment may be related with the decrease in both air and soil temperatures, resulting in reducted leaf respiration and thus compensate net photosynthesis.

• 센서학회지
• /
• 제17권2호
• /
• pp.133-142
• /
• 2008

Respiration is induced by muscular contraction of the chest and abdomen, resulting in the abdominal volume change. Thus, continuous measurement of the abdominal dimension enables to monitor breathing activity. Conductive rubber cord has been previously introduced and tested to develop wearable application for respiratory measurements. The present study implemented wireless wearable respiratory monitoring system with the conductive rubber cord in the patient's pants. Signal extraction circuitry was developed to obtain the abdominal circumference changes reflecting the lung volume variation caused by respiratory activity. Wireless transmission was followed based on the zigbee communication protocol in a size of 65mm${\times}$105mm easily put in pocket. Successful wireless monitoring of respiration was performed in that breathing frequency was accurately estimated as well as different breathing patterns were easily recognized from the abdominal signal. $CO_2$ inhalation experiment was additionally performed in purpose of quantitative estimation of tidal volume. Air mixed with $0{\sim}5%\;CO_2$was inhaled by 4 normal males and the respiratory air flow rate, abdominal dimension change, and end tidal $CO_2$ concentration were simultaneously measured in steady state. $CO_2$ inhalation increased the tidal volume in normal physiological state with a correlation coefficient of 0.90 between the tidal volume and the end tidal $CO_2$ concentration. The tidal volume estimated from the abdominal signal linearly correlated with the accurate tidal volume measured by pneumotachometer with a correlation coefficient of 0.88 with mean relative error of approximately 8%. Therefore, the tidal volume was accurately estimated by measuring the abdominal dimension change.

• 원예과학기술지
• /
• 제29권3호
• /
• pp.224-231
• /
• 2011

'후지' 사과의 8개월 장기저장 후 모의수출과정에서 품질에 미치는 수확 후 1-MCP 처리와 CA저장의 효과를 분석하였다. 장기저장용 성숙기로는 다소 늦은 10월 29일에 청원지역과 안동지역 두 과수원에서 수확한 사과를 $1{\mu}L{\cdot}L^{-1}$ 1-MCP 처리를 한 후 8개월 간 $0^{\circ}C$ 저온저장과 controlled atmosphere(CA) 저장을 수행하였다. 저장 후 2주 저온 컨테이너 운송과 현지유통 7일로 설정한 수출과정은 추가적인 2주 저온저장과 $20^{\circ}C$ 실온보관 방식으로 모의하였다. 1-MCP 처리 및 CA저장은 저장 및 모의운송 후 호흡과 에틸렌 발생을 억제하였고 모의 수출과정 후까지 적정 산도와 과육경도 유지에 뚜렷한 효과를 보였다. 그러나 장기저장에 적합한 성숙단계를 지나 수확한 사과의 경우, 1-MCP 처리만으로는 수출 시장에서 소비자 관능을 만족시키는 조직감 유지에 충분한 효과를 거두기 어려운 것으로 평가되었다. 본 연구 결과, 수확 시기가 지연되는 '후지' 사과의 8개월 이상 장기저장 후까지 수출 품질을 유지하기 위해서는 CA저장 혹은 1-MCP 처리/CA저장 병용 프로그램 적용의 필요성이 제시되었다

• 한국식품저장유통학회지
• /
• 제6권2호
• /
• pp.153-160
• /
• 1999

후지 사과의 CA 저장 효과를 생리화학적으로 구명하기 위해 저장 조건에 따른 에틸렌과 이산화탄소 생성 및 이들의 연관성 그리고 과육경도와 과피색의 변화를 조사하였다. 저장 산소농도가 낮을수록 ACC oxidase 활성이 억제되어 내부 에틸렌 농도가 낮게 유지되었다. 특히 1% $O_2$+l% $CO_2$ 조건에서는 내부 에틸렌 농도가 1 ppm 이하로 유지되었으며 저장 후 2$0^{\circ}C$의 air에서도 거의 변화가 없었다. 에틸렌 생성에 고농도 이산화탄소의 영향은 구성 산소농도에 의존적이어서 1% 산소에서는 효과가 없거나 생성 증가 효과를, 3% 산소에서는 생성 억제효과를 나타내었다. 내부 에틸렌 농도와 에틸렌 방출량은 밀접한 상관관계을 나타내었다. 내부 이산화탄소 농도도 이산화탄소 방출량과 밀접한 상관관계를 나타내었으며 저장 산소농도가 가장 낮은 조건인 1% $O_2$+l% $CO_2$에서 가장 낮게 유지되었고 저장 후의 증가폭은 다른 조건들과 차이가 없었다. 저장조건에 따른 에틸렌과 이산화탄소 생성량의 연관성은 CA 저장 사과와 단기간 air 저장 사과에서는 존재하였으나 장기간 air 저장 사과에서는 보이지 않았다. 사과의 과육경도와 과피의 녹색은 에틸렌과 이산화탄소의 생성이 억제된 저장조건일수록 손실이 적었다.

• 한국산업보건학회지
• /
• 제20권4호
• /
• pp.236-240
• /
• 2010

This study demonstrates the use of a chemical containing potassium superoxide (KO2) to convert carbon dioxide (CO$_2$) in air to oxygen (O$_2$). A oxygen generating closed-circuit SCBA (self contained breathing apparatus) removes carbon dioxide by a chemical reaction with potassium dioxide that consumes the carbon dioxide and produces oxygen. Considering the disasters, there is a need to develop strategies to enable the introduction of self-contained self rescuers (SCSR). The potassium superoxide reacts with the wears breath to produce oxygen and absorb carbon dioxide. If the respiration rate of a person is 5 MET (metabolic equivalent), to say 30 L/min, at disaster such as fire, mass of potassium superoxide was evaluated as 33.3 g with yield and safety factor. Four researchers tested on a laboratory treadmill breathing through SCSRs in a closed circuit, it appears useable for 9 minutes.