• 한국토양비료학회지
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• 제46권2호
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• pp.81-86
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• 2013

For organic farming, green manure crops such as leguminous forages and barley have been broadly used to improve soil fertility and soil physical and chemical properties by repeatedly cutting and mulching them directly as winter crop in the field in the rotation. In this investigation we selected 78 agricultural farm corporations as well as individual organic farmhouses related to crop rotation from greenmanure crops to main crops in order to analyze the relationship of cropping system between main crops and green manure crops. The results showed that the green manure crops were divided into two groups as leguminous and nonleguminous crops, representing that those are limited to specific climate and farming systems of regions. Also the 10 or less green manure crops including sudangrass, hairyvetch, italian ryegrass, sorghun, buckwheat, oat, pea, rye, clover, and canola which belong to leguminous crops which are presently cultivated from the organic farmhouses within the rotational crop system. We also confirmed that the major main crops are sweet potato, soybean, corn, tobacco, spinach from usage frequency analyzed by NetMiner H 2.6 which was used to estimate the rotational cropping system among the green manure crops and main crops.

• 한국물환경학회지
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• 제22권3호
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• pp.534-539
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• 2006

The supply of oxygen for aeration is the largest energy consumer at activated sludge wastewater treatment plants. Replacement of less efficient aeration systems with fine pore aeration devices can save up to 50 percent of aeration energy costs. The purpose of this study was the diagnosis and evaluation of a domestic wastewater aeration system by the off-gas method which had been studied by US EPA and ASCE. For this study, an off-gas analyzer and its hood were made to collect off-gas. Also, a vacuum pump was connected to the analyzer to make suction of off-gas. Experiments were conducted at a domestic activated sludge wastewater treatment plant which had a single spiral roll aeration system installed with P.E tube diffuser. Data on OTE(f), SOTE(pw), OUR, and air flow rate were obtained from these experiments. In case of replacing an aeration system, it is recommended that it should be replaced with perforated membrane disc or ceramic disc fine bubble diffusers installed in a full floor coverage or grid pattern.

• Weed & Turfgrass Science
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• 제3권3호
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• pp.206-214
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• 2014

외국으로부터 도입된 관상식물의 귀화 사례가 국내외에서 다수 보고되고 있다. 외래 관상식물의 국내 생태계 영향 파악을 위한 기초자료를 확보하고자, 국내의 귀화식물 309종을 대상으로 관상식물로 분류할 수 있는 78종의 목록을 작성하고, 생활형과 원산지 전세계적인 귀화 및 규제 현황을 분석하였다. 국내에 귀화한 외래 관상식물은 국화과 식물이 23종으로 가장 많았다. 75종이 초본으로 대부분을 차지하였으며, 다년생 식물이 일년생 및 이년생 식물에 비해 많았다. 유럽과 북아메리카가 원산지인 식물이 가장 많았으며, 약모밀을 제외한 나머지 77종은 해외에서도 귀화 사례가 보고되었다. 미국쑥부쟁이와 양미역취 등 34종은 국내 또는 해외에서 규제 또는 주의 대상으로 분류된 종들이므로, 이들의 확산을 방지하기 위한 모니터링이 필요할 것이다.

• 대한기계학회논문집A
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• 제35권9호
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• pp.1137-1143
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• 2011

초고온가스로의 중간열교환기는 원자로에서 생산된 $950^{circ}C$ 정도의 초고온 열을 수소생산 공장으로 전달하는 핵심 기기이다. 한국원자력연구원에서는 중간열교환기의 후보 형태로 고려되고 있는 인쇄기판형 열교환기의 소형 시제품을 제작하였다. 본 연구는 소형가스루프 시험조건하에서 인쇄기판형 열교환기 소형 시제품의 고온 구조건전성을 시험수행 전에 미리 평가하기 위한 작업의 일환으로 인쇄기판형 열교환기 소형 시제품에 대한 고온 구조해석 모델링, 거시적 열 해석 및 구조 해석을 수행하고 그 결과들을 정리한 것이다. 해석 결과는 곧 수행될 인쇄기판형 열교환기 소형 시제품 성능시험결과와 비교하고 또한 향후 제작될 중형 시제품 설계/제작에 반영할 것이다.

• 생약학회지
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• 제34권3호통권134호
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• pp.228-232
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• 2003

For effective management of atopic dermatitis, it is important to introduce a therapeutic agent although having the fewest side effects, has the greatest anti- inflammatory effect. In the course of screening anti-inflammatory agents, we obtained BSASM composed of several plant extracts. This study was designed to investigate anti-inflammatory and immunomodulatory effects of BSASM. As a first step, $NF-{\kappa}B$ luciferase reporter assay was performed to know the involvement of BSASM in the production of proinflammatory cytokines because $NF-{\kappa}B$ element has been known to play a major role in expression of cytokine genes such as interleukin-8 (IL-8) or tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})$. LPS (lipolysaccharide)-induced $NF-{\kappa}B$ activation was inhibited by BSASM. In addition, we found the fact that BSASM inhibits LPS-induced produced production of IL-8 and $TNF-{\alpha}$ proinflammatory cytokines, indicating BSASM has anti-inflammatory effect. In interleukin-2 (IL-2) luciferase reporter assay in Jurkat T cells, BSASM reduced PHA (Phytohemagglutinin)-induced IL-2 luciferase activity, suggesting the possibility that BSASM might also have an immunomodulatory function in T cell-mediated immune response. Based on these results, we suggest the possibility that BSASM can be introduced to improve symptom of immune-related skin diseases, namely, atopic dermatitis.

• 상하수도학회지
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• 제19권2호
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• pp.135-143
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• 2005

It was evaluated that the effect of turbidity removal by Pore Controllable Fiber Filter(PCF) installed in NS(Naksang) small water treatmant plant(system) using under flow water as raw water in the study. The results of the study are as the followings. Firstly, the removal efficiency of turbidity by PCF without coagulation(in operation mode not using coagulants) was mostly below 20 percent. On the other hand, when operation using proper coagulants, that of turbidity was mostly over 80 percent. Secondly, slow sand filtration after PCF, total turbidity removal efficiency of final treated water was 84.3 percent, and the contribution by PCF was 57.1 percent and that of slow sand filtration was 27.7 percent. Therefore the introduction of PCF as pre-treatment process would be helpful to reduce the loading of high turbidity of slow sand filtration. Thirdly, the results of particle counter measurements showed that when operated PCF with coagulants, fine flocs captured or adsorbed at the pore of PCF were flow out into the effluents from 120 minutes after backwashing because of the increase of headloss of PCF. Therefore the decision of backwashing time should made consideration into the outflow of fine flocs from PCF. Fourth, coagulant dosages on PCF at the same turbidity was largely variable because of the effect of the raw water characteristics and the turbidity increase velocity at rainy days, therefore flexible coagulant dosages should be considered rather than fixed coagulant dosage by the influent jar-test result.

• 대한기계학회논문집
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• 제16권3호
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• pp.598-607
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• 1992

본 연구에서는 고온중 장시간 사용중에 일어나는 야금학적 성질의 변화의 추 원인인 특정 탄화물을 비파괴적으로 검출하기 위해, 최근에 연구 되고 있는 전기화학 적 방법을 응용하기 위한 기초연구이다. 한편으로는 비파괴적 방법의 실험실적 연구 를 현장에 응용시키기 위한 시도를 행하고, 본 연구 결과를 이용한 향후 설비 진단 시 스템의 개요를 고찰해 보인다.

• 비파괴검사학회지
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• 제21권1호
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• pp.32-38
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• 2001

재료의 손상을 평가하기 위하여 초음파법에 대한 많은 연구가 진행되었고 널리 사용되고 있으나 대부분 균열의 성장 또는 두께의 감소와 같은 문제에 집중되고 있다. 본 연구에서는 2.25Cr-1Mo 강을 이용하여 반복하중에 의해 재료내부에 발생하는 미시균열을 조기에 감지하고, 피로에 의한 파괴를 미연에 방지할 수 있도록 초음파 표면파의 감쇠와 속도변화를 이용하여 균열길이 측정의 정량적인 평가방법을 제시하였다. 중심주파수 5MHz의 탐촉자를 이용하여 파단수명비 약 60%, 균열길이 약 2mm 정도에서 표면파의 속도 및 감쇠 변화를 탐지할 수 있었다. 고주파 탐촉자를 이용함으로써 미시균열의 발생을 조기에 탐지할 수 있으며, 파단수명을 예측하는 기초자료로 활용할 수 있다.

• 한국식품위생안전성학회지
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• 제29권4호
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• pp.383-390
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• 2014

The safety of a new natural plant composition (ADP) was assessed on the genotoxicity study and 14-day repeat dose toxicity study. ADP contains a mixed water extract obtained from the mixture of Phellodendron cortex (Phellodendron amurense) and Anemarrhena rhizoma (Anemarrhena asphodeloides), and poses the contractile properties mediated by alpha-adrenoceptor of the prostate and urethra as well as antioxidant and anti-inflammatory properties. In order to evaluate genetic safety, in vivo micronucleus test was performed in ICR mice orally administered with three dose levels of 1250, 2500, 5000 mg/kg body weight, and vehicle and positive control. In the 14 days study, Sprague-Dawley rats were treated with ADP at the dose levels of 500, 1000, 2000 mg/kg once a day, and clinical signs, body weights, hematology, serum biochemistry, necropsy findings and organ weights were monitored and examined. In experimental results, ADP treatment, compared with vehicle control, did not induce the micronucleated erythrocytes from mouse bone marrow. In the 14 days study, any significant and toxicological differences in all measurements of parameters were not observed in ADP treatment groups of animals, compared with vehicle treatment. The No-Observed-Adverse-Effect-Level (NOAEL) of ADP in the 14 days study was determined to be greater than 2000 mg/kg/day in both sexes.

• 에너지공학
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• 제8권4호
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• pp.605-611
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• 1999

화력발전설비 고온요소의 잔여수명평가는 주로 비파괴검사 및 검사결과의 파괴역학적 해석등으로 행해졌다. 그러나 기존 방법은가동중에는 적용되기 어렵고 급작스런 운전이력에 대한 정량적인 손상을 평가할 수 없었다. 따라서 구조물의 형상, 운전이력 및 재료물성에 근거하여 실시간 수명소비율 및 잔여수명을 평가하는 기술의 개발이 요구되고 있다. 본 연구에서는 고온 증기헤더의 수명을 실시간으로 평가하는 감시시스템 소프트웨어를 개발하였다. 고온헤더에 대하여 해석된 온도, 응력, 그린함수를 이용하여 취약부위의 실시간 응력을 계산하고 천이 사이클을 카운트하여 크리프 및, 피로수명을 계산하였다. 본 소프트웨어를 개발함으로써 운전이력에 따른 소비수명을 실시간으로 평가하고 운전정보를 기록하여 향후 운전계획, 보수주기 및 교체시기를 결정하는데 지침이 되도록 하였다.