• 한국산학기술학회논문지
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• 제16권12호
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• pp.8665-8672
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• 2015

본 연구에서는 하수처리장의 소화슬러지(digest sludge)를 대상으로 악취제거 및 유기물제거에 대한 타당성을 검토하고자 BIO-CLOD를 넣은 반응조와 넣지 않은 반응조에 대하여 24시간, 48시간, 72시간 후 ammonia, methyl mercaptan(MMC) 및 $H_2S$에 대해서 측정하였다. BIO-CLOD를 침적시킨 반응조(BIO-CLOD)에서 24시간 내에 ammonia는 48%인 것에 비해 $H_2S$와 MMC는 98%이상의 높은 제거율을 보인 반면에 BIO-CLOD를 침적시키지 않은 반응조(Non BIO-CLOD)에서는 24시간 내에 ammonia가 45%, $H_2S$는 71%, MMC는 84%로서 악취제거 가능성을 보였다. 암모니아 농도는 시간이 지남에 따라 감소하면서 질산성질소농도는 증가하는 질산화 현상을 보였으며, 소화슬러지내의 유황계 악취성분들이 호기성 미생물들에 의해 산화 분해되어 용액 중의 황산염농도를 증가시키는 데는 BIO-CLOD효과가 있었음을 알 수 있었으며, 황산염농도증가와 대기중의 $H_2S$ 제거율간에는 상관관계가 있음을 알수 있었다. 반응조 유출수에서 유기물의 감소는 짧은 시간 내에서는 BIO-CLOD가 영향을 주지 않았으며, HRT 12시간과 HRT 24시간으로 운전하였을 때 경제적인 면에서 HRT 12시간을 고려해야 할 것으로 판단되었다.

• Journal of Forest and Environmental Science
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• 제28권1호
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• pp.12-18
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• 2012

Like any other natural resources, forest flora may experience the extreme threat of elevated temperature and saline water submergence at different stages of their lives i.e. from germination to maturity due to climate change effects. The overall aim of the study was to measure the effect of higher temperatures along with saline water irrigation on survival and initial growth during seedling stage of Artocarpus chapalasha. The experiment was conducted in temperature- humidity-photoperiod regulated plant growth chamber during stipulated period to measure the growth performance of randomly selected seedlings. Within three different elevated temperatures viz. $30^{\circ}C$, $32^{\circ}C$ and $34^{\circ}C$, the seedlings were given three different saline conditions such as 0.5 g/L, 1.5 g/L and 2.5 g/L NaCl concentrations. Results found from the experiment was that, seedlings of Artocarpus chaplasha reared at different temperatures and saline water treatments showed stunted growth than reared at existing outdoor temperature ($26.31^{\circ}C$) irrigated with regular fresh water. Seedling growth at three different parameters such as height, collar diameter and number of leaves showed that with increasing temperature individuals respond negatively to increasing saline condition. The seedling's growth occurred at every day in height, collar diameter and leaf. However, growth rate reduced later during the observation. The combined effect of high salinity and higher elevated temperature results in seedling mortality. Therefore, Artocarpus chaplasha may not thrive at higher temperature and salinity intrusion at its early growing period in plantation and natural forest areas.

• 한국환경생태학회지
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• 제22권6호
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• pp.640-647
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• 2008

댐호, 저수지, 하천 등 수위변동이 있는 비탈면의 녹화용 식물재료를 선발하기 위하여 내습성을 지닌 4종류의 Iris속 식물을 대상으로 완전침수와 부분침수 조건에서 침수기간별로 생존 및 생장특성 등을 비교 조사하였다. 생존율과 생장상태를 기준으로 한 내침수성은 노랑꽃창포 > 꽃창포 > 부채붓꽃 > 붓꽃의 순서로 나타났다. 특히, 노랑꽃창포는 120일까지의 완전침수 조건에서 생장장해를 입기는 하지만 생존율이 높았고 지속적으로 양호한 생장을 하였으며, 부분침수조건에서는 침수기간이 증가할수록 생장이 양호한 것으로 보아 내침수성이 강한 것으로 확인되었다. 붓꽃, 부채붓꽃, 꽃창포는 완전침수조건에서 다소 많은 생장장해를 입으며 90일 이후에 고사되었으나, 내침수성이 비교적 강한 것을 확인할 수 있었으며, 수위변동에 따라 생장회복이 가능할 것으로 판단된다. 본 시험을 통해 댐호의 저수 비탈면과 각종 저수구역 내의 식생공사용으로서 노랑꽃창포, 꽃창포, 부채붓꽃, 붓꽃의 이용가능성을 확인하였다.

• 한국작물학회지
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• 제38권4호
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• pp.360-365
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• 1993

벼 기계이앙 어린모 육묘시 생장조절제가 묘의 초장신장 촉진에 미치는 효과를 구명하기 위하여 화성벼를 공시하고 6가지의 생장조절제를 사용하여 종자침종 효과와 6가지의 생장조절제를 사용하여 종자침종 효과와 묘 생장을 조사하여 다음과 같은 결과를 얻었다. 1. Gibberellin과 Metalaxyl은 어린모의 초장신장을 촉진시켰으며, Tetracycle은 초장을 억제하였다. 2. Gibberellin의 엽면분무처리가 종자침종처리보다 어린모의 초장신장에 더 효과적이었다. 3. 어린모의 초장신장 촉진을 위한 Gibberellin의 엽면분무처리의 적정농도는 약 10ppm이었다. 4. Gibberellin의 엽면분무의 적정처리시기는 파종후 3～4일 이었다.

• 한국작물학회지
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• 제38권3호
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• pp.228-234
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• 1993

벼 건답휴립직파재배에서 발아시 토양수분과 입묘율과의 관계를 구명하기 위하여 칠성벼, 가유벼, 삼강벼, 영산벼, 영덕벼, 화진벼, 팔공벼, 섬진벼, 도진벼, 밀양 9005, M101, M202, Newbonnet, Tebonnet, Lemont 등 15개 품종을 공시하여 여러가지 토양수분함량과 복토심을 달리하여 파종시험을 하여 얻은 결과를 요약하면 다음과 같다. 1. 파종 후 4일간 담수하였다가 배수하여도 출아율에는 영향이 없었다. 2. 담수조건에서 1.5cm 복토하였을 때 출아율은 40%이하로 토양표면에 파종한 것보다 출아율이 현저히 낮았고, 품종간에는 영산벼와 섬진벼의 출아율이 가장 높았다. 3. 국장에서 파종 후 상면 10cm까지 관수하여도 출아율에 영향을 미치지 않았다. 4. 토양수분은 관수 및 강우 후 3～6일간은 pF0이었고, 산화환원전위는 443～453mV로 무관수보다 낮았다.

• 대한토목학회논문집
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• 제26권1B호
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• pp.119-124
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• 2006

본 연구의 목적은 간헐포기공정(IABR)과 막결합 간헐포기공정(IAMBR)의 오염물질 제거능력과 영양염류 제거 mechanism을 비교 검토하여 막침적의 타당성을 확보하고 질산화율 및 탈질율을 산정하였으며, 질소물질수지를 수립하고자 하였다. 그 결과로서 IAMBR과 IABR의 경우 유기물 제거에 있어서는 큰 차이를 보이지 않았으나 영양염류 제거능력은 IAMBR이 IABR에 비해 높게 나타났다. 또한, 무산소 상태에서 반응조 내의 질산성 질소 농도가 IAMBR이 낮게 유지되는 것으로 보아 높은 탈질화 반응이 일어난 것으로 판단되며, 질소물질수지의 결과에서도 IAMBR에서 탈질된 질소성분이 40.9%로 IABR의 10.7%보다 4배 이상 높은 탈질능력을 보였다. 따라서, 높은 MLSS 농도의 유지와 간헐적 유입 유출 방식의 적용이 가능한 장점을 지니고 있는 막이 월등한 질소제거능력의 차를 보임으로써 간헐포기공정에 대한 막결합의 타당성이 충분한 것으로 사료된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권2호
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• pp.37-46
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• 2012

This study was conducted to identify groundwater recharge and discharge amounts of a representative urban-rural composite area located in Yongin city, Kyounggi-do, Korea. Groundwater recharge would be affected by mainly two processes in the study area: rainfall and leakage from public water pipelines including water-supply and sewage system. Groundwater recharge rate was estimated to be 13.5% by applying annual groundwater level data from two National Groundwater Monitoring Stations to the master regression curve method. Subsequently, the recharge amounts were determined to be $13,253{\times}10^3m^3/yr$. Leakage amounts from water-supply and sewage system were estimated to be $3,218{\times}10^3$ and $5,696{\times}10^3m^3/yr$, respectively. On the whole, a total of the recharge amounts was $22,167{\times}10^3m^3/yr$, of which 60% covers rainfall recharge and 40% pipeline leakage. Groundwater discharge occurred through three processes in the composite area: baseflow, well pumping, and discharge from urban infrastructure including groundwater infiltration into sewage pipeline and artificial extraction of groundwater to protect underground facilities from submergence. Discharge amounts by baseflow flowing to the Kiheung agricultural reservoir and well pumping were estimated to be $382{\times}10^3$ and $1,323{\times}10^3m^3/yr$, respectively. Occurrence of groundwater infiltration into sewage pipeline was rarely identified. Groundwater extraction amounts from the Bundang subway line as an underground facility were identified as $714{\times}10^3m^3/yr$. Overall, a total of the discharge amounts was determined to be $2,419{\times}10^3m^3/yr$, which was contributed by 29% of artificial discharge. Even though groundwater budget of the composite area was identified to be a surplus, it should be managed for a sound groundwater environment by changing deteriorated pipelines and controlling artificial discharge amounts.

• 융합정보논문지
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• 제10권10호
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• pp.115-122
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• 2020

기후변화에 의해 전례없는 폭우가 빈번하게 내려 도심지에서는 인명 및 재산 손실 등의 침수피해를 반복적으로 겪고 있다. 도심지 침수의 두가지 주요 인자는 하천범람과 내수침수이다. 그러나, 기존 대부분의 연구에서는 침수의 두가지 주요 인자에 의한 복합적인 기작을 무시하고 각 결과를 단순 선형합으로 침수 영향을 산정하여 부정확한 결과를 도출하였다. 본 연구에서는 내수침수와 하천범람을 동시에 모의하여 분석하였다. 하천범람 해석을 위해 Petrov 안정화 기법을 적용하여 충격파의 전달을 정확하게 포착할 수 있도록 하였으며, Flux-blocking 알고리즘을 탑재하여 마름/젖음을 안정적으로 모의하였다. 또한 EGR 기법에 의한 생성/소멸항을 천수방정식에 추가하여 내수침수 해석 모듈을 반영하였다. 내수침수와 하천범람을 동시에 모의하는 경우 침수와 범람에 의한 흐름의 상쇄효과와 중첩효과를 보다 정밀하게 반영할 수 있으므로, 개별합으로 산정한 결과에 비해 정확한 결과를 도출할 수 있었다.

• 한국작물학회지
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• 제37권2호
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• pp.198-208
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• 1992

Recently, a nursery mat made from rock wool has realized transplanting of the younger seedlings with the ordinary transplanting machines for Chibyo and Chubyo(3 and 4～5 leaved seedling, respectively). The seedlings defined as the 'Nyubyo' or 'Nursling seedlings' became possible to achieve economic profits from the reduction in both working time and costs. It being widely noticed as a strategy to solve the difficulties in current rice cultivation. The nursling seedlings are 1.4 to 2.5 leaves and height at 4.5 to 7cm, grown 4 to 7 days after seeding. They maintain still up to 50 to 80% of their nutrients in the endosperm, and can grow by using only their own nutrients for a certain period of time after transplanting. Nursling seedlings take 2 days in the nursery chamber at 32$^{\circ}C$ after seeding, and 2 days in the greening house at $25^{\circ}C$. This is only 4 days, all together, to make the nursling seedlings of 1.5 leaves which are ready for transplanting. Watering is only needed once at the sowing time. It only takes 1 or 2 waterings even to raise a seedlings for a period of 7 days. The number of nursery boxes can be reduced because it is possible to sow more densely(220 to 240g per box), thus it only needs seedlings of 15 to 16 boxes per 10 a which leads to a reduction in facilities and space needed. Temperature during the nursery period can be artificially adjusted more precisely which may lead to the prevention of temperature stress. The nursling seedlings can root rapid by because the crown roots from the coleoptile node begin to emerge immediately after transplanting. They show strong resistance to low temperature (12$^{\circ}C$) and deep-planting. There is no danger in the rooting of the seedlings even if half of their height is buried into the soil. Moreover, it can root at a rate of up to 65 to 80% even if the full height of the seedlings is buried. They show also strong resistance to submergence (10～15cm). The nursling seedlings tend to grow by producing tillers from lower nodes. It is therefore, necessary to control to keep the proper numbers of tillers per unit area. They have no fear in the delay of heading and their yield components can be so well balanced that the same level of yield was achieved with the nursling seedlings compared to that with Chibyo. It was further suggested that if the surplus tillers can be avoided by such cultivation practices, the number of grain per panicle can be kept greater and higher yield can be realized. Practical experiments with the nursling seedlings conducted in 1989 and 1990 by farmers in various areas showed exciting results. The nursling seedlings will become widely spread, or at least occupy an important position in Japanese and also in Korean rice cultivation techniques.tivation techniques.

• 한국양식학회지
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• 제16권3호
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• pp.142-150
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• 2003

Performance of a biological filter, the rotating biological contactor (RBC), is affected by rotational speed and hydraulic residence time (HRT). A RBC with a disc diameter of 62 cm, total surface area of 48.28 $m^2$, volume of 0.34 ㎥, and submergence ratio of 35.4% was tested for the combinations of five rotational speeds (1, 2, 3, 4 & 5 rpm) and three HRT (0.5, 1.0 & 2.0 hr) to find out the maximum removal efficiencies of total ammonia nitrogen (TAN) and nitrite nitrogen of a simulated recirculating aquaculture system. Ammonia loading rate in the system was 25 g of TAN/ ㎥. day. Removal efficiencies were checked when TAN concentrations in the system stabilized for 3 days in each treatment. The concentration of TAN in the system decreased with increasing rotational speed of the RBC up to 4 rpm in all HRT (P<0.05). At the rotational speed of 5 rpm, the efficiencies decreased in all HRT (P<0.05). When the rotational speeds were 1, 2, 3, 4, and 5 rpm, TAN concentrations in the system were 1.35, 0.94, 0.69, 0.66, and 0.76 mg/L at the 0.5 hr HRT, 2.86, 1.18, 0.96, 0.87, and 1.11 mg/L at the 1.0 hr HRT, and 5.30, 2.44, 1.99, 1.77, and 2.01 mg/L at the 2.0 hr HRT, respectively. The TAN removal efficiencies of the RBC at the rotational speeds of 1, 2, 3, 4, and 5 rpm were 32.9, 49.5, 65.1, 72.9, and 62.9% in 0.5 hr HRT,33.1, 74.1, 87.1, 95.8, and 78.5% in 1.0 hr HRT, and 35.5, 76.7, 89.6, 97.0, and 85.5% in 2.0 hr HRT, respectively. TAN removal efficiency of RBC per pass increased with increasing HRT. However, TAN concentration in the system also increased. The best operating condition among the treatments was obtained at the treatment of 0.5 hr HRT and 4 rpm (P<0.05). The TAN concentration was 0.66 mg/L. Concentrations of nitrite nitrogen (NO$_2$$^{[-10]}$ -N) in the system decreased with increasing rotational speed in all HRT while that in the system increased with increasing HRT in all rotational speeds. The ranges of NO$_2$$^{[-10]}$ -N concentrations at HRT of 0.5, 1.0, and 2.0 hr in the system were 0.26~0.32, 0.31~0.56, and 0.43~l.45 mg/L, respectively. The ranges of daily removal rates of TAN in this system were 20.03~23.0 g TAN/㎥ㆍday and those of nitrite nitrogen were 19.65~30.25 g NO$_2$$^{[-10]}$ -N/㎥ㆍday.