• Environmental Engineering Research
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• 제11권3호
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• pp.156-163
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• 2006

In this study, substrate removal characteristics were analyzed to reduce the cost of external carbon dosage at Sudokwon Landfill Site Management Corporation in Korea by utilizing oxygen uptake rate (OUR) and nitrate uptake rate (NUR) tests. To estimate and evaluate the substrate removal characteristics obtained by the batch tests, the lab-scale MLE process was operated. By-products of J Co. (sugar manufactory) and S Co. (fine chemical industry) were selected as the concerned carbon sources through a comparison of carbon and nitrogen contents. MeOH was tested as a control experiment. Until the steady state, the fraction of $RBDCOD_{OUR}$ concentration to COD concentration of J Co., S Co. by-products and MeOH increased and reached levels of 98%, 82%, and 100%, respectively. During the 20th operating day, the fraction of $RBDCOD_{NUR}$ concentration to COD concentration was 95%, 81%, and 83%, respectively. These fractions of $RBDCOD_{NUR}$ concentration to $RBDCOD_{OUR}$ concentration increased according to acclimation periods and reached levels of 99%, 97%, and 81%, respectively, on the 20th day. The results obtained from the lab-scale MLE process operation using the concerned carbon sources as external carbon were similar to that observed by OUR and NUR tests.

• 한국응용곤충학회지
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• 제21권2호
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• pp.68-72
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• 1982

인삼 재배포장에서 병원균인 Fusarium spp.의 밀도와 근부에 영향을 미치는 토양환경요인을 조사하였다. 2년근 포장의 토양을 토성별로 분류하여 결주율, Fusarium spp. 밀도, 화학적 성질을 비교해 본 결과 점토 함량이 들었고 결주율과 질산태 질소는 줄어드는 경향이었으며 다른 성질은 뚜렷한 차이가 없었다. 6년근 포장에서는 근부율과 유효인산 함량이 정의 상관(r=0.3162, p=0.05)을 보였으며 Fusarium spp. 밀도와 Streptomyces spp. 밀도는 고도의 부의 상관(r=-0.3976, p=0.01)을 나타내었다.

• 한국환경과학회지
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• 제8권6호
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• pp.691-697
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• 1999

The work on the eutropication of Youngsan river was conducted from Jul. 1997 to Jun. 1998. The value of water temperature in the study area varied from $4^{\circ}C\;to\;32^{\circ}C$ with an annual mean of $17.5^{\circ}C$. DO varied from 4.0 $mg/{\ell}$ to 13.5 $mg/{\ell}$, with an annual mean 10.2 $mg/{\ell}$,. BOD varied from 0.8 $mg/{\ell}$, to 6.4 $mg/{\ell}$ with an annual mean 3.1 $mg/{\ell}$. COD varied from 4.6 $mg/{\ell}$, to 9.0 $mg/{\ell}$ with an annual mean 6.38 $mg/{\ell}$. Nitrate varied from 1.58 $mg/{\ell}$, to 6.77 $mg/{\ell}$, with an annual mean of 3.475 $mg/{\ell}$, Total-nitrogen varied from 2.14 $mg/{\ell}$ to 8.38 $mg/{\ell}$ with an annual mean of 5.083 $mg/{\ell}$. Total-phosphate varied from 0.035 $mg/{\ell}$ to 0.588 $mg/{\ell}$ with an annual mean of 0.128 $mg/{\ell}$. Chl.a varied from 1.8 ${\mu}g/{\ell}$ to 75.0 ${\mu}g/{\ell}$ with an annual mean of 19.55 ${\mu}g/{\ell}$. The euthrophic state index of $Carlson^{16)}$ were showed 61.8(TP) and 71(SD) value

• 자원리싸이클링
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• 제16권6호
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• pp.52-60
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• 2007

탈질 특허분석과 전해기초연구를 통하여 수용액으로부터 질소의 환원제거에 대하여 조사하였다. 세계적으로 수용액으로부터 질소를 제거하는 방법으로 생물학적 기술과 산화환원 기술이 개발되고 있으며, 최근 들어 전해기술에 대한 특허출원도 증가하고 있다. 전해법에서 Fe를 음극으로 Pt를 양극으로 채택한 정전류 전해법에 의하여 1시간동안 총질소를 47% 이상 제거할 수 있었다. 질소함유 폐수를 처리하는 효율적인 방법은 폐수 특성에 맞는 기술의 조합이라고 말할 수 있다. 예를 들어 고농도 질소 함유 폐수를 소량 배출하는 경우 화학적 처리와 전해법의 조합으로 질산성 질소를 아질산성 질소로 일차 전환시켜 전해효율을 극대화시키면서 2차 오염원인 용해 금속이온을 전해과정에서 음극에 환원 회수하는 방법 등이 실용화에 유리하다고 말할 수 있다.

• 한국초지조사료학회지
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• 제17권3호
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• pp.223-230
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• 1997

The experiments were undertaken to investigate the dynamics of $NO_3\;^-$ uptake at low temperature with forage rape(Bmssica napus), barle(Hordeum vulgare) and winter rye (Scale cereale). A net $NO_3\;^-$uptake and the contents of nitrogenous compound in tissues at low temperature ($5^{\circ}C$) were compared with normal temperature ($25^{\circ}C$).The net uptake of $NO_3\;^-$ by Brass ica nqus was the highest among three species at both temperature applied. During 9 hours after temperature treatment, $NO_3\;^-$ uptake of Brassica napus, Hordeum vulgm and Scale c e d e grown at $5^{\circ}C$ decreased to about 31, 50 and 27% compared with those grown at $25^{\circ}C$. $NO_3\;^-$ contents in roots were much sensitively affected by low temperature than those of leaves. Comparing with the plants grown at $25^{\circ}C$, $NO_3\;^-$ contents in roots of increased to 48.3, 38.7 and 53.5% repectively, for Brassica napus, Hordeum vulgare and Scale cereale during 9 days. A relatively less changes in the content of $NH_4\;^+$-N were observed according to the temperature treatment. The ontents of amino acids-N in leaves at $5^{\circ}C$ slightly decreased while that of roods remarkably increased compared with $25^{\circ}C$. Protein-N was the largest pool of nitrogen and its contents in leaves and roots showed a similar response on the temperature treatment. These results suggested that $NO_3\;^-$uptake was inhibited at low temperature. The dynamics of $NO_3\;^-$ uptake could be closely related to the increased concentration of $NO_3\;^-$ and amino acids in roots.

• 한국세라믹학회지
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• 제24권1호
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• pp.70-76
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• 1987

The effect of C12A7 and OH group on the synthesis of C3A by the sol-gel process using aluminum-sec-butoxide and calcium nitrate was studied. C3A by sol-gel method was compared with C3A obtained by the conventional method with respect to their reactivity of formation and crystal size. The sol-gel process for initial formation of C12A7 and C3A at lower temperature (1100, 1200$^{\circ}C$) was superior, but that for complete crystallization of C3A at higher temperature (1300, 1400$^{\circ}C$) was inferior to oxide mixture process. When heat treated under the atmosphere oxygen-free dried nitrogen eliminate the influence of OH group in C12A7, the reactivity of C3A from sol-gel sample incorporated OH group were poor, whereas that from oxide mixture sample showed remarkable effect. The poor crystallization of C3A at higher temperature is presumed to be due to the fact that incorporated OH group in C12A7 formed at lowr temperature might interrupt the diffusion of CaO to C12A7 to from C3A. The crystal size and the hydration characteristics of both C3A obtained by different processes exhibited almost the same results.

• 한국작물학회지
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• 제26권2호
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• pp.192-197
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• 1981

Alfalfa에 대한 국내분이 근유균의 유효성과 효과적인 근유균 접종방법을 밝히고져 배지상에서 이들 균주의 근유형성 및 질소고정능력을 검토한 다음 이들 균주에 3가지 종자접종방법을 적용하여 사경재배를 실시한 결과는 다음과 같다. 1. 근유균 접종에 따른 근유의 형성은 접종 2주후부터 볼 수 있었고 유묘의 생장은 대조구보다 현저히 증가되있으며 질업처리구(70ugN/ml)와 차이가 없어 두 균주는 모두 유교균주로 평가되었다. 2. 두 균주 모두 Broth-vacuum 방법으로 접종한 것은 근규의 형성은 있었으나 실험기간 중 유묘의 생장에 있어서는 무접종 대조구와 차이가 없었다. 3. Peat & lime pelleting 방법은 두 균주 모두에서 근유형성과 유묘생장을 현저히 증가시켰으나 Peat-adhesive 방법은$ A_1$ strain 에서 만 효과적이었다. 4. 근유의 무게와 지상부 건물중 그리고 근유의 무게와 근중사이에는 두 균주 모두에서 고도의 정의 상관관계가 인정되었다.

• 대한환경공학회지
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• 제33권11호
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• pp.804-811
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• 2011

본 연구는 흡착제의 흡착특성을 이해하는데 이용되는 각종 흡착모델의 적용성을 평가하는데 목적이 있다. 이를 위해 상용의 음이온교환수지(PA-308)를 이용하여 질산성질소에 대한 흡착특성을 회분식 실험을 통해 조사하였다. 음이온교환수지에 의한 질산성질소의 속도실험 결과는 초기의 빠른 흡착과정과 후기의 느린 흡착 과정의 두 가지 단계의 과정으로 이원화되는 경향을 나타내었다. 1차 속도식과 2차 속도식 모두 전체 반응시간에서의 질산성질소에 대한 음이온교환수지의 흡착속도를 수식화 할 수 없었다. 초기의 빠른 흡착반응($t\leq$ 20분)은 1차 속도식에 따르고 외부확산에 의해 거의 지배되는 거동을 보이는 반면, 후기 느린 흡착반응(t > 20분)은 2차 속도 화학반응과 내부확산, 즉 세공 내 확산에 의해서 일어남을 알 수 있었다.

• 동의생리병리학회지
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• 제19권2호
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• pp.429-433
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• 2005

We investigated the effects of aqueous extract from talc for suppression in the process of cyclophosphamide-induced cystitis in the rat. The weight of urinary bladder was increased in the cyclophosphamide-injected rat compared with normal, but the increase of weight was arrested by intake of talc. More similar results showed in the uric test involving nitrate content and blood cell number and serum analysis involving the content of blood urea nitrogen and uric acid in the talc challenged rat compared with control one. More severe histological changes of urinary bladder such as edema, wall thickness, bleeding, vacuolation in mucosal epithelium were demonstrated in the rat injected with cyclophosphamide compared with normal. Fewer scores of these changes such as edema and bleeding were observed in rats treated with talc. In the immunohistochemical analysis, the expression of inflammatory-related protein examined tended to increase in the urinary bladder of cyclophosphamide-injected rat, especially COX-2 and $TNF-{\alpha}$ in mucosal epithelium and iNOS and $IL-1{\beta}$ in mucosal and muscular layer. The decline of these immunoreation were observed in the talc treated rat, significant decrease of COX-2 was detected in mucosal epithelium and iNOS in submucosal layer. These results suggest that talc may use as a useful therapeutic agent for noninfectious cystitis.

• 한국토양비료학회지
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• 제36권3호
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• pp.145-153
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• 2003

조사지역의 평균 토양화학성은 pH 5.93, 유기물함량 $25.9g\;kg^{-1}$, 유효인산 $742mg\;kg^{-1}$, $NO_3-N$ $44.7mg\;kg^{-1}$ 이었으며, 토양 1 g당 균근균 포자는 양파 12.1, 마늘 11.7, 고추 10.1로 작물별 큰 차이를 보이지 않았다. 토성에 따른 포자수는 식토와 미사질 식토에서 토양 1 g 당 15개 이상의 포자밀도를 보였으며, 토양 pH, OM, $NO_3-N$, Av. $P_2O_5$등 토양양분함량과 포자밀도는 유의성 있는 상관관계를 보이지 않았으나, 포자수는 양분농도와 관계없이 일정한 수준을 보였다. 종이 확인된 균근균 수집 포자는 Glomus속 2종과 Gigaspora속 3종으로 Glomus clarum, Glomus intraradices, Glomus etunicatum와 Gigaspora rosea, Gigaspora margarita 등 이었다.