• Journal of Biosystems Engineering
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• 제25권3호
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• pp.221-226
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• 2000

Hot air heater with light oil burner is the most common heater for greenhouse heating in the winter season in Korea. However, since the thermal efficiency of the heater is about 80∼85%, considerable unused heat amount in the form of exhaust gas heat discharges to atmosphere. In order to capture this exhaust heat a heat recovery system for plant bed heating in the greenhouse was built and tested in the hot air heating system of greenhouse. The heat recovery system is made for plant bed or soil heating in the greenhouse. The system consisted of a heat exchanger made of copper pipes, ${\Phi}12.7{\times}0.7t$ located in the rectangular column of $330{\times}330{\times}900mm$, a water circulation pump, circulation plastic pipe and a water tank. The total heat exchanger area is 1.5$m^2$, calculated considering the heat exchange amount between flue gas and water circulated in the copper pipes. The system was attached to the exhaust gas path. The heat recovery system was designed as to even recapture the latent heat of flue gas when exposing to low temperature water in the heat exchanger. According to the performance test it could recover 45,200 to 51,000kJ/hr depending on the water circulation rates of 330 to $690\ell$/hr from the waste heat discharged. The exhaust gas temperature left the heat exchanger dropped to $100^{\circ}C$ from $270^{\circ}C$ by the heat exchange between the water and the flue gas, while water gained the difference and temperature increased to $38^{\circ}C$ from $21^{\circ}C$ at the water flow rate of $690\ell$/hr. By the feasibility test conducted in the greenhouse, the system did not encounter any difficulty in operations. And, the system could recover 220,235kJ of exhaust gas heat in a day, which is equivalent of 34% of the fuel consumption by the water boiler for plant bed heating of 0.2ha in the greenhouse.

• 한국식물병리학회지
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• 제14권3호
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• pp.247-252
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• 1998

A series of greenhouse test was conducted to evaluate infection of Calonectria ilicicola on soybean plants of different ages at time of inoculation. Lesion length and number of perithecia were determined on cultivars Braxton, Deltapine 726, and Riverside 699 that were 10∼40 days old and 4-10 days old at time of inoculation. Quadratic and linear relationships were described between plant age at inoculation and lesion length or perithecia production in greenhouse studies. Soybean seedlings exhibited low susceptibility to C. ilicicola regardless of cultivar susceptibility. On 8- or 1-0-days-old Braxton, lesion lenght and perithecia numbers were reduced. Lesion lengths were longest on plants 30 days old whereas perithecia production was greatest on plants 20∼30 days old at time of inoculation. Differences in lesion length and perithecia production that were observed on young plants (4∼10 days old) were similar to relative levels of susceptibility in soybean cultivars in greenhouse and field tests, suggesting that reaction to C. ilicicola in soybean cultivars may be determined early in plant development.

• 한국농공학회지
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• 제43권1호
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• pp.96-101
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• 2001

In designing the greenhouse structures, snow and wind loads must be estimated on the basis of the probability of occurrence of snow or wind storms of a given intensity. The recurrence interval chosen depends on the standard durable years and safety factors of the greenhouse. This study was carried out to find the standard durable years of pipe framed greenhouses. Bend test for metallic materials was conducted on samples of galvanized steel pipes being used in greenhouse frames. A secular change of collapse loads and flexural rigidity for galvanized steel pipes were analyzed with the parts buried in the ground and exposed in the atmosphere. From those experimental results and corrosion rate of galvanized film, the standard durable years for pipe framed greenhouses are estimated as follows ; the small scale pipe houses of movable type is 7∼8 years and the large scale pipe houses of fixed type is 14∼15 years.

• 한국균학회지
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• 제48권4호
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• pp.519-521
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• 2020

Damping-off symptoms were frequently observed on young plants of Indian lettuce (Lactuca indica) grown in a farmer's vinyl greenhouse located in Goseong, Gangwon province of Korea during a disease survey in June 2019. The incidence of diseased plants in the vinyl greenhouse investigated was 30-50%. Four isolates of Rhizoctonia sp. were obtained from the diseased plants and identified as Rhizoctonia solani AG-4 based on the morphological characteristics and anastomosis test. Three isolates of R. solani AG-4 were tested for pathogenicity on Indian lettuce by artificial inoculation. All the tested isolates induced damping-off symptoms on the inoculated plants. The symptoms were similar to those observed in plants from the farmer's vinyl greenhouse investigated. This is the first report of R. solani AG-4 causing damping-off in Indian lettuce.

• 식물병연구
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• 제27권1호
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• pp.45-47
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• 2021

Damping-off symptoms were frequently observed on young plants of coastal hogfennel (Peucedanum japonicum) grown in a farmer's vinyl greenhouse located in Goseong, Gangwon Province, Korea during a disease survey in June 2019. Incidence of the diseased plants was 50-70% in the vinyl greenhouse investigated during the disease survey. Eight isolates of Rhizoctonia sp. were obtained from the diseased plants. All the isolates were identified as Rhizoctonia solani AG-4 based on the morphological characteristics and anastomosis test. Three isolates of R. solani AG-4 were tested for pathogenicity on coastal hogfennel by artificial inoculation. All the tested isolates induced damping-off symptoms on the inoculated plants. The symptoms were similar to those observed in the farmer's vinyl greenhouse investigated. This is the first report of R. solani AG-4 causing damping-off in coastal hogfennel.

• 한국균학회지
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• 제49권2호
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• pp.249-251
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• 2021

Damping-off symptoms were frequently observed in young deltoid synurus (Synurus deltoides) plants grown in a farmer's vinyl greenhouse located in Hwacheon, Gangwon Province, Korea, during a disease survey in July 2019. The incidence of diseased plants in the vinyl greenhouse investigated was 5-30%. Five isolates of Rhizoctonia sp. were obtained from the diseased plants and identified as Rhizoctonia solani AG-1 (IB), based on morphological and cultural characteristics and anastomosis test results. Three isolates of R. solani AG-1 (IB) were tested for pathogenicity on deltoid synurus using artificial inoculation. All the tested isolates induced damping-off symptoms in the inoculated plants. The symptoms were similar to those observed in plants from the farmer's vinyl greenhouse. To our best knowledge, this is the first report of R. solani AG-1 (IB) causing damping-off in deltoid synurus.

• 현장농수산연구지
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• 제18권1호
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• pp.101-112
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• 2016

본 연구는 원예시설의 원격제어에 대한 불안감을 해소하고 신뢰성을 확보하기 위하여 감시 및 제어 기능과 안정성을 높인 ICT기반 온실제어시스템을 개발하고 비닐하우스에 적용하여 그 성능을 검증하고자 하였다. 온실 환경 제어 시스템은 온실의 환경 정보를 취득하는 센서와 센서G/W로 구성된 센서부와 온실의 환경을 제어하는 PLC, 이더넷 통신을 통해 환경 정보 데이터와 구동부의 작동상태를 수집하고 외부 서버와 연계되어 환경정보와 제어정보를 전달하는 로컬서버, 천.측창, 커튼 등을 작동시키는 구동부, 재배작물과 작동부 감시를 위한 카메라 등으로 구성하였다. 온실 환경 제어 시스템은 현장제어와 원격 제어 간의 충돌을 방지하기 위해 원격/로컬 상태 구분을 위한 선택 스위치와 원격제어에 따른 안전성을 확보하기 위한 안전장치를 마련하였다. 즉, 각 내부장치를 동작시키는 전자개폐기, 조작 스위치로부터 상태를 수집하며, 모터 등 과부하 발생 시 과부하계전기의 TRIP신호를 감지하여 운영자의 컴퓨터와 스마트폰으로 경보가 보내지도록 구현하였다. 소프트웨어는 웹브라우저를 이용한 HMI(Human Machine Interface) 구현으로 관리자 페이지를 통해 다수의 브라우저에서도 지원 가능하도록 하였다. 또한, 모바일 웹방식을 도입하여 안드로이드, 아이폰 등 운영체제와 상관없이 구동할 수 있도록 구현하였다. 제어화면은 운영자가 한눈에 알아보기 쉽게 온실의 모형과 부대 장치와 작동기기를 이미지화하여 동작 상태를 표시하도록 하였으며, 작동 버튼을 클릭하여 수동조작도 가능하도록 구현하였다. 온실 환경 제어 시스템 성능시험결과 천창, 측창, 수평커튼, 측면커튼은 작동 조건에 따라 모두 성공적으로 작동함을 확인하였다. 또한, 소프트웨어의 데이터 수집 및 디스플레이 상태, 이벤트 출력, 영상모니터링 등 계측 및 제어성능 모두 양호하게 나타났다.

• 생물환경조절학회지
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• 제32권4호
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• pp.449-455
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• 2023

본 연구에서는 한 온실 내에서 딸기 재배 베드를 관부 난방 적용 베드, 관행 베드 2처리로 나누고 동일 환경에서 관부 난방이 딸기 재배 환경, 출뢰, 개화 및 수확량에 미치는 영향을 분석하였다. 관부 난방 전 두 처리에서 딸기 관부 온도 및 배지 온도는 큰 차이 없었으며, 외기온이 낮은 12월, 1월, 2월에는 시험구의 주간 평균 딸기 관부 온도는 대조구에 비해 1.3℃ 높았으며, 야간 평균 딸기 관부 온도는 대조구에 비해 2.7℃ 높게 나타났다. 주간 배지 온도는 시험구가 대조구보다 평균 1.7℃ 높았으며, 야간 배지 온도는 시험구가 대조구보다 평균 2.4℃ 높게 나타났다. 딸기 관부 온도와 출뢰 기간에 대한 상관분석 및 회귀분석을 수행한 결과 상관계수는 -0.86으로 높은 음의 상관관계를 보여 관부 온도가 높을수록 출뢰 기간이 짧아지는 경향이 있었으며, 결정계수는 0.74로 높은 설명력을 보였다. 딸기 화아분화는 10-20℃에서 촉진되고, 5-10℃, 25-30℃에서는 효과가 없으며, 5℃ 이하 및 30℃ 이상일 때는 저해되는데, 대조구 온실이 외기온이 낮은 12월, 1월, 2월에, 특히 야간의 딸기 관부 온도가 월별로 각각7.3℃, 7.6℃, 8.8℃로 나타나 10℃ 이하로 유지되면서 화아분화가 촉진되지 않았고, 시험구에 비해 출뢰, 개화가 늦은 것으로 판단된다. 3월 말까지의 딸기 수확량은 시험구 392.6g/plant, 대조구 346.0g/plant로 관부 온돡 높았던 시험구에서 약 13.5% 높게 나타났으며, 딸기의 품질은 2L 등급과 L 등급의 비율이 시험구 62.4%, 대조구 58.5%로 시험구에서 높은 등급의 딸기 비율이 더 많은 것으로 나타났다. 딸기의 화아분화의 주요인은 온도이고, 2차적 요인은 일장이므로 추후 연구를 통해 관부 온도뿐만 아니라 일장 등 다양한 요소를 고려하여 딸기 생육, 수확량의 변화를 분석해보는 연구도 필요하다고 판단된다.

• 한국분무공학회지
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• 제23권4호
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• pp.227-233
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• 2018

An automobile is composed of a combination of a lot of parts, and it is difficult to maintain the same performance from a new car until it's scrapped. Greenhouse gases included in automobile emissions are typically carbon dioxide and methane. It is expected that this greenhouse gas will change depending on the aging (cumulative mileage) of the automobile However, the greenhouse gas characteristics by cumulative mileage lack of actual data due to time and economic difficulties. Therefore, in this paper, we selected automobile with high sales by displacement in korea and carbon dioxide and methane were measured by using method of the related law. The cumulative mileage is as follows; within 160 km (Statutory mileage by 2010), 6500 km (current statutory mileage), 15000 km (approximately 1-year average mileage of Non-business passenger vehicle). As a result of the test, the emission of carbon dioxide and methane was the smallest at 6,500 km, and increased in order of 15000 km, within 160 km. Also, it was confirmed that the $CO_2$ emission change of a large displacement automobile is more smaller at each mileage. Although the greenhouse gas tends to increase as the mileage of the vehicle, it is thought that additional confirmation is required of since 15,000 km as well, because it can occur deviations due to taming process or mechanical friction of the automobile.

• Journal of Biosystems Engineering
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• 제27권6호
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• pp.565-572
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• 2002

In order to control the root-zone temperature of greenhouse crops in the hydroponics at hot and cold season, heat pump system for cooling and heating was built and tested in this work. The system was air-to-water type and vapour compression type. The heating and cooling mode was selected by the four way valve. Capacity of the compressor was 3.75㎾ and heat transfer area of the evaporator and the condenser were 3.05㎡ and 0.6㎡, respectively. According to the performance test, it could supply heat of 42,360 to 64,372kJ/h depending on the water circulation rate of 600 to 1,500ℓ/h, respectively, when indoor air temperature was 10∼20$\^{C}$. COP of heat pump system was 3.0 to 4.0 in the heating mode. But, COP of the cooling mode was 1.3 to 2.1 at indoor temperature of 20∼35$\^{C}$. The feasibility test in the greenhouse the developed heating and cooling system was installed, showed that the heating cost of the developed system was only about 13% of that of the conventional heating system. The heating cost of the developed system was 367won/day(electric consumption 9.7㎾h/day), while that of the conventional system was 2,803won/day(oil consumption 7.7ℓ/day) at the same heating mode.