• Journal of Bio-Environment Control
• /
• v.20 no.1
• /
• pp.1-7
• /
• 2011

The objective of the present study is to identify the applicability of a low pressure fogging system for cooling commercial tomato greenhouse. In particular, the cooling system in this experiment utilizes low pressure spray nozzles which were developed in Korea recently. The experimental result that the temperature in fog-cooled greenhouse was lower than the non-cooled greenhouse showed the cooling effect by the low pressure fogging system. But because the relative humidity in fog-cooled greenhouse was comparatively low, the satisfactory cooling effect could be acquired by narrowing the space of fog nozzles and extending fogging time to supply more fog spray quantity. The variation of temperature distribution in fog-cooled greenhouse along timelag was insignificant during short time, but that was great during long period of day. This result showed the variation of temperature along timelag was slight by fog cooling but great by other factors like radiation, ventilation, air flow, etc. The advanced operation technology of fog system was required to reduce the variation of temperature along time lag. We plan to suggest the advanced installation and operation technology of low pressure fogging system for cooling commercial tomato greenhouse by further experiments in near future.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.18 no.4
• /
• pp.253-263
• /
• 2016

Chrysanthemum production would benefit from crop growth simulations, which would support decision-making in crop management. Chrysanthemum is a typical short day plant of which floral initiation and development is sensitive to photoperiod. We developed a model to predict phenological development and leaf appearance of chrysanthemum (cv. Baekseon) using daylength (including civil twilight period), air temperature, and management options like light interruption and ethylene treatment as predictor variables. Chrysanthemum development stage (DVS) was divided into juvenile (DVS=1.0), juvenile to budding (DVS=1.33), and budding to flowering (DVS=2.0) phases for which different strategies and variables were used to predict the development toward the end of each phenophase. The juvenile phase was assumed to be completed at a certain leaf number which was estimated as 15.5 and increased by ethylene application to the mother plant before cutting and the transplanted plant after cutting. After juvenile phase, development rate (DVR) before budding and flowering were calculated from temperature and day length response functions, and budding and flowering were completed when the integrated DVR reached 1.33 and 2.0, respectively. In addition the model assumed that leaf appearance terminates just before budding. This model predicted budding date, flowering date, and leaf appearance with acceptable accuracy and precision not only for the calibration data set but also for the validation data set which are independent of the calibration data set.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.10
• /
• pp.725-731
• /
• 2016

This study numerically investigates the thermal performance of a 2.0-kW butane-based combustion heating system for an electric vehicle under cold conditions. The system is used for cabin space heating and coolant-based battery thermal management. ANSYS CFX 17 software was used for parametric analysis. The mass flow rates of cold air and coolant were varied, and their effects were compared. The numerical results were validated with theoretical studies, which showed an error of 0.15%. As the outside air mass flow rates were increased to 0.005, 0.01, and 0.015 kg/s, the cabin supply air temperature decreased continuously while the coolant outlet temperature increased. When the coolant mass flow rates were increased to 0.005, 0.01 and 0.015 kg/s, the air temperature increased while the coolant outlet temperatures decreased. The optimal mass flow rates are discussed in a consideration of the requirements for high cabin heating capacity and efficient battery thermal management.

• Journal of the Korean Applied Science and Technology
• /
• v.35 no.4
• /
• pp.1307-1319
• /
• 2018

As interests in the air pollution increases, many kinds of researches are underway on the reduction of air pollutants. The removal of nitrogen oxides from the emission gas of diesel vehicles using urea solution has shown a great effect. The quality of urea solution is strictly defined by domestic law, but the increase of impurities in urea solution reduces the effect of reducing nitrogen oxides. Therefore, in this study, the change of physical properties of urea solution was analyzed after heating the urea solution for a certain temperature and time. Also, the changes of physical properties of urea solution were analyzed according to kinds of storage container and temperature for storing the urea solution. After heating the urea solution for a certain period of time, the biuret content in urea solution increased and the content of urea decreased. As the urea content decreased, both density and refractive index decreased. In the storage stability test carried out at a constant temperature with iron and PET containers, no change in physical properties was observed.

• 농업기술회보
• /
• v.46 no.6
• /
• pp.34-35
• /
• 2009

무더운 여름 날씨가 끝나면 낮과 밤의 일교차가 큰 환절기인 가을철을 맞이하게 된다. 특히 면역능력과 체력이 낮은 어린 가축들은 환경(온도, 풍속, 습도 등)의 변화에 의한 대사불균형 스트레스를 받기 때문에 각별한 관리를 통해 생산성 저하와 질병을 예방해야 한다. 아침 저녁으로 바깥의 찬 공기에 노출되지 않도록 차단하며, 낮에는 충분히 환기를 해주고, 밤에는 보온이 되도록 한다.

• 프린팅코리아
• /
• v.11 no.7
• /
• pp.136-136
• /
• 2012

본격적인 여름이 다가오고 있다. 벌써부터 무더운 초여름 날씨가 이어지고 있는 가운데 올 여름은 폭염과 열대야가 자주 발생하는 등 찜통더위가 기승을 부릴 것으로 보인다. 특히 여름은 야외 활동이 많은 계절이라 디지털카메라의 원치 않는 고장으로 불편을 호소하는 사용자가 많다. 디지털카메라는 온도나 습도 등의 요인에 민감하기 때문에 여름철 관리에 각별한 주의가 필요하다.

• 건강소식
• /
• v.35 no.12
• /
• pp.6-8
• /
• 2011

사람의 신체 활동이 가장 원활하고 건강하게 이루어지는 최적의 체온은 $36.5^{\circ}C$에서 $37.1^{\circ}C$이다. 그리고 이 체온을 유지하기 위해서는 적절란 운동, 따뜻한 음식을 먹는 식사습관, 질 좋은 수면이 요구된다. 이렇게 체온을 올리는 생활을 꾸준하게 지속하면 암을 비롯한 당뇨병, 골다공증, 비만, 불임, 치매 같은 다양한 질환이 예방되며 건강한 삶을 누릴 수 있다.

• KOREAN POULTRY JOURNAL
• /
• v.27 no.10 s.312
• /
• pp.146-149
• /
• 1995

최근 양계장에서는 규모에 상관없이 질병이 발생하여 막대한 피해가 속출하고 있는 실정이다. 발병되는 대표적인 질병으로는 뉴캣슬, 가금티푸스, 추백리 등 다양한 병명을 보이는데 어느 질병이나 일단 발병하면 치유책이 없이 도태를 실시해야 한다는 측면에서 엄청난 피해를 입히고 있어 이미 예상 보다 생산량이 감소하여 가격이 폭등하는 등 많은 문제점이 나타나고 있다. 이 같이 생산성이 저하되는 것은 사전에 사양관리가 제대로 이루어지지 않아 체중 조절에 실패하거나, 환기가 불량하여 닭이 약해져 질병에 노출이 되기 쉽다는 점에서 병아리 때부터 철저한 사양관리가 이루어져야한다.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2011.05a
• /
• pp.27-28
• /
• 2011

• KOREAN POULTRY JOURNAL
• /
• v.42 no.6
• /
• pp.101-103
• /
• 2010