• 한국환경복원기술학회지
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• 제7권4호
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• pp.110-119
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• 2004

This research was conducted to develop spraying cultivation method using forest topsoils in order to restore the disturbed slopes. In November the researcher collected a depth of 5 cm of topsoils from a well developed forest, after the fallen leaves were cleared. The essential results of the research are as follows: In the case of using the forest topsoils, during the early stages of planting, time is necessary for the desired vegetation to reach a similar state to the vegetation being restored. The best possible effect is obtained through a method utilizing forest topsoil(30%)+loam silt soil(70%)+seeding with grasses and native plants including trees, shrubs, and herbs. Several plants such as Pinus densiftora, Potentilla fragarioides, Miscanthus sinensis, Erigeron canadensis seemed to be naturally emerged from the topsoils From this experiment, it was recommended that environment potential within topsoil should be comprehended. Also, topsoil deposit and gathering methods should be experimented properly.

• KSBB Journal
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• 제6권3호
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• pp.231-240
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• 1991

Recently, developments of large scale and high density cell culture methods have been the objects of many researches, because the demand of various pharmaceutical products produced by animal cell culture has been rapidly increasing. The cell culture equipment should have the requirements such as sufficient oxygen transfer and mixing, low shear stress and surface tension, and small foaming. In order to develop a proper bioreactor meeting these requirements simultaneously, a perfluorocarbon having high solubility of oxygen was sprayed into the medium as an oxygen carrier instead of air. Also, a new impeller was developed and combined together with the perfluorocarbon spraying system so as to design a new bioreartor for cell cultivation. The new impeller had better characteristics of mixing and oxygen transfer than the paddle and cell-lift impellers based on the same, shear rate. But, it was observed that the volumetric oxygen transfer coefficient of the new bioreactor decreased with increasing cell density during E. coli fermentation.

• Journal of Biosystems Engineering
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• 제37권5호
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• pp.287-295
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• 2012

Purpose: Some of the most representative approaches are to apply next generation technologies to save energy consumption, fully automated control system to appropriately maintain environmental conditions, and autonomous assistance system to reduce labor load and ensure operator's safety. Nevertheless, improvement of upcoming method for soil cultured greenhouse has not been sufficiently achieved. Geometrical complexity of ground in protected crop cultivation might be one of the most dominant factors in design of autonomous vehicle. While there is a practical solution fairly enough to promise an accurate travelling, such as autonomous sprayer guided by rail or induction coil, for various reasons including the limitation of producer's budget, the previously developed sprayer has not been widely distributed to market. Methods: In this study, we developed an autonomous sprayer considering travelling performance on geometrical complexity of ground in soil cultured greenhouse. To maintain a stable travelling and to acquire a real time feedback, common wire with 80 mm thick and body frame and sprayer boom. To evaluate performance of the prototype, tracking performance, climbing performance and spraying boom's uniform leveling performance were individually evaluated by corresponding experimental tests. Results: The autonomous guidance system was proved to be sufficiently suitable for accurate linear traveling with RMS as lower than approximately 10 cm from designated path. Also the prototype could climb $10^{\circ}$ of ground's slope angle with 40 kg of water weight. Uniform leveling of spraying boom was successfully performed within $0.5^{\circ}$ of sprayer boom's slope. Conclusions: Considering more complex pathways and coarse ground conditions, evaluations and improvements of the prototype should be performed for promising reliability to commercialization.

• 한국자원식물학회지
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• 제26권1호
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• pp.52-59
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• 2013

본 연구는 실내 조경 및 분화용 소재로 활용가치가 높은 물가양털이끼(Brachythecium rivulare)와 쥐꼬리이끼(Myuroclada maximowiczii)의 적정 재배법을 개발하기 위하여 수행하였다. 원예상토 위에 천을 덮어 재배하는 것이 재배용기에 천이나 토양만 사용하는 방법에 비해 이끼 2종의 생육이 왕성하고, 수확이 편리하였다. 재배 토양은 바크나 피트모스 보다는 원예상토를 사용하였을 때 생육 및 수확의 편이성이 우수하였다. 식재할 때는 이끼를 분주하는 것 보다 믹서기로 분쇄하여 재배용기 위에 산포하는 방법이 이끼 2종의 배우체 발생과 수확 편이도 개선에 효과적이었다. 또한 재배용기($27{\times}17{\times}3cm$)에 물가양털이끼는 2.0 g, 쥐꼬리이끼는 4.0 g을 식재하였을 때, 생육이 가장 왕성하였고 수확이 편리하였다. 양액(N:P:K=20:20:20)을 농도별로 처리하였을 때 물가양털이끼는 무처리구에 비해 전반적으로 생육이 억제되었고, 고농도로 갈수록 생체중의 증가량이 감소하였다. 그러나 쥐꼬리이끼는 $0.25g{\cdot}L^{-1}$ 처리구에서 생체중의 증가량이 가장 많았다. 따라서 물가양털이끼와 쥐꼬리이끼는 원예상토 위에 천을 덮어서 만든 재배용기에 각 2.0, 4.0 g의 이끼를 분쇄하여 산포한 다음 충분한 수분을 공급하고, 쥐꼬리이끼는 재배기간 동안 저농도의 양액을 처리해주는 것이 적합한 재배법으로 생각된다.

• 한국환경농학회지
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• 제42권1호
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• pp.28-34
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• 2023

Nitrogen fertilizers applied to agricultural lands for crop cultivation can be volatilized as ammonia. The released ammonia can catalyze the formation of ultrafine dust (particulate matter, PM2.5), classified as a short-lived climate change pollutant, in the atmosphere. Currently, one of the prominent methods for fertilizer application in agricultural lands is soil surface application, which comprises spraying the fertilizers onto the soil surface, followed by mixing the fertilizers with the soil. Owing to the low nitrogen absorption rate of crops, when nitrogen fertilizers are applied in this manner, they can be lost from land surfaces through volatilization. Therefore, investigating a new fertilization method to reduce ammonia emissions and increase the fertilizer utilization efficiency of crops is necessary. In this study, to develop a method for reducing ammonia emissions from nitrogen fertilizers applied to soil surfaces, deep fertilization was conducted using a newly developed deep fertilization device, and ammonia emissions from barley, garlic, and onion fields were examined. Conventional fertilization (surface application) and deep fertilization (soil depth of 25 cm) were conducted for analysis. The fertilization rate was 100% of the standard fertilization rate used for barley, and deep fertilization of N, P, and K fertilizers was implemented. Ammonia emissions were collected using a wind tunnel chamber, and quantified subsequently susing the indole-phenol blue method. Ammonia emissions released from the basal fertilizer application persisted for approximately 58 d, beginning from approximately 3 d after fertilization in conventional treatments; however, ammonia was not released from deep fertilization. Moreover, barley, garlic, and onion yields were higher in the deep fertilization treatment than in the conventional fertilization treatment. In conclusion, a new fertilization method was identified as an alternative to the current approach of spraying fertilizers on the soil surface. This new method, which involves injecting nitrogen fertilizers at a soil depth of 25 cm, has the potential to reduce ammonia emissions and increase the yields of barley, garlic, and onion.

• 한국환경농학회지
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• 제40권3호
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• pp.149-160
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• 2021

BACKGROUND: Concerns have been raised about the impact of recent high concentrations of fine dust on human health. Ammonia(NH₃) reacts with sulfur oxides and nitrogen compounds in the atmosphere to form ultrafine ammonium sulfate and ammonium nitrate (PM2.5). There is a growing need for accurate estimates of the amount of ammonia emitted during agricultural production. Therefore, in this study, ammonia emissions generated from the cultivation of leafy perilla in plastic houses were determined. METHODS AND RESULTS: Cow manure compost, swine manure compost, and poultry manure compost each at 34.6 ton ha^-1, the amount commonly used by farmers in the field, was sprayed on the soil surface. Just after spraying cow manure compost, swine manure compost, and poultry manure compost, the ammonia was periodically measured and analyzed to be 22.5 kg ha^-1, 22.8 kg ha^-1, and 85.2 kg ha^-1, respectively. The emission factors were estimated at 70.0 kg-NH₃ ton-N, 62.8 kg-NH₃ ton-N, and 234.1 kg-NH₃ ton-N, respectively. Most ammonia was released in the two weeks after application of the compost and then the amount released gradually decreased. CONCLUSION: Therefore, it is necessary to improve the emission factor through a study on the estimation of ammonia emission by type of livestock manure and major farming types such as rice fields and uplands, and to update data on the production, distribution, and sales of livestock manure.

• 한국환경농학회지
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• 제41권4호
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• pp.230-235
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• 2022

BACKGROUND: Ammonia gas emitted from nitrogen fertilizers applied in agricultural land is an environmental pollutant that catalyzes the formation of fine particulate matter (PM2.5). A significant portion (12-18%) of nitrogen fertilizer input for crop cultivation is emitted to the atmosphere as ammonia gas, a loss form of nitrogen fertilizer in agricultural land. The widely practiced method for fertilizer use in agricultural fields involves spraying the fertilizers on the surface of farmlands and mixing those with the soils through such means as rotary work. To test the potential reduction of ammonia emission by nitrogen fertilizers from the soil surface, we have added N, P, and K at 2 g each to the glass greenhouse soil, and the ammonia emission was analyzed. METHODS AND RESULTS: The treatment consisted of non-fertilization, surface spray (conventional fertilization), and soil depth spray at 10, 15, 20, 25, and 30 cm. Ammonia was collected using a self-manufactured vertical wind tunnel chamber, and it was quantified by the indophenol-blue method. As a result of analyzing ammonia emission after fertilizer treatments by soil depth, ammonia was emitted by the surface spray treatment immediately after spraying the fertilizer in the paddy soil, with no ammonia emission occurring at a soil depth of 10 cm to 30 cm. In the upland soil, ammonia was emitted by the surface spray treatment after 2 days of treatment, and there was no ammonia emission at a soil depth of 15 cm to 30 cm. Lettuce and Chinese cabbage treated with fertilizer at depths of 20 cm and 30 cm showed increases of fresh weight and nutrient and potassium contents. CONCLUSION(S): In conclusion, rather than the current fertilization method of spraying and mixing the fertilizers on the soil surface, deep placement of the nitrogen fertilizer in the soil at 10 cm or more in paddy fields and 15 cm or more in upland fields was considered as a better fertilization method to reduce ammonia emission.

• 한국환경농학회지
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• 제33권3호
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• pp.198-204
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• 2014

'신고'배에서 나타나는 과피얼룩과 발생을 경감하기 위하여 생육기 동안 몇 가지를 처리한 결과는 다음과 같다. 배과피얼룩 증상은 유과기(5월 25일)부터 발생하기 시작하여 수확 시까지 나타났으며 과육에는 전혀 발생하지 않았다. 과피얼룩과 발생은 수세가 정상적인 나무, 지베렐린 과경 도포 처리에서 현저하게 낮았으나, 아미노산 수체살포는 큰 차이가 없었다. 봉지에서는 칼슘이 코팅된 봉지 및 석회유황합제가 코팅된 봉지에서 과피얼룩과 발생이 낮았다. 봉지 내지에 석회유황합제 및 콩기름 도포는 과피얼룩이 아닌 약해를 유발시켰다. 과피얼룩 발생과의 수피 및 과피는 K 농도가 높았으나 엽에서는 T-N 및 K 농도는 오히려 낮았다.

• 식물병연구
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• 제26권4호
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• pp.239-249
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• 2020

2019년 국내의 사과와 배에 화상병이 크게 발생한 원인을 파악하기 위하여 화상병 발생한 30개 과원을 대상으로 각각의 발생 상황과 농가 면담을 통해 경종적 특징 등을 조사하였다. 화상병은 이미 감염된 지 2년 이상 오래 된 과원에서 대부분 발생하였는데, 이런 원인은 (1) 농가가 병 증상을 정확히 알지 못하여 농작업과 방화곤충 등을 통해 과원 내에서 퍼지게 되고, (2) 방화곤충이나 농작업자 등에 의해 처음 발생 과원에서 주변 과수원으로 확산되었고, (3) 동일 경작자 또는 공동 농작업자에 의해 근거리 또는 원거리로 확산된 것이라고 추정할 수 있다. (4) 이런 일련의 과정이 새롭게 확산된 지역에서 반복되다가 농가들이 화상병을 알게 되면서 신고가 증가한 것이 2019년 화상병 대발생의 일련의 원인이라고 추정할 수 있었다. 국내에서 화상병 확산을 최소화하기 위해서는 조기진단을 위한 철저한 농업인 교육과 무병징 식물체에서도 화상병균 진단이 가능한 정량적 검출기술이 요구되고 있다. 또한 큰 열매를 주로 생산하는 국내 재배법에 적합한 약제방제 체계 개발이 필요하다. 화상병 방제에서 가장 중요한 가지의 궤양 증상, 묘목, 양봉장 등의 전염원 관리를 위해서 과원별 병원균의 분자역학연구를 통해 정확한 확산경로를 구명할 것을 제안한다.

• Weed & Turfgrass Science
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• 제4권2호
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• pp.118-123
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• 2015

메타게놈(metagenome)은 연구실에서 배양이 불가능한 미생물을 포함한 자연계에 존재하는 미생물의 유전자를 직접 연구하는 학문분야이다. 지구상 거의 모든 자연, 인공 환경에서 살고 있는 미생물 DNA를 분리 정제하는 것이 가능하며, 재조합 DNA 기술 등을 이용하여 배양 가능한 숙주미생물에 메타지놈을 클로닝함으로서 메타지놈 라이브러리를 제작할 수 있다. 최근 메타게노믹스를 통하여 자연계에 존재하고 있는 대다수의 미생물들이 실험실에서 배양되지 않았던 이유를 구명할 수 있게 되었고, 그들이 가지고 있는 생태학적인 의미와 역할에 대한 이해와 더불어 점차 그 응용 분야와 범위도 확대되고 있다. 이와 같은 메타게놈의 응용 분야 확대의 한 방안으로 본 연구에서는 새로운 제초활성 물질 및 제초활성 물질 생산에 필요한 유전자를 확보하기 위해 메타게놈 라이브러리를 대상으로 오이 떡잎절편 검정, 미세조류 생장저해 검정, 종자발아 저해 검정의 HTS (high throughput screening) 시스템을 구축하였고, 구축된 시스템으로부터 선발된 최종 단일 클론인 9-G1과 9-G12의 바랭이에 대한 in vivo assay를 통해 본 연구에서 개발한 HTS 시스템의 유효성을 확인 하였다. 후속연구로서 활성단일클론이 만들어내는 제초활성물질의 동정 및 제초활성물질을 합성하는 유전자군에 대한 연구를 수행 중에 있다.