• 농약과학회지
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• 제4권2호
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• pp.44-49
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• 2000

본 시험은 오이 양액재배시 배양액내 규산칼륨($K_{2}SiO_{3}$) 처리에 의한 생육단계별 규소의 흡수특성, 체내분표 병원균의 침입억제 효과를 검토하기 위하여 수행하였다. 잎에서의 규소 분포는 TEM, SEM 및 EDX-ray를 사용하여 4개(SEM, Ca, Si, K)의 구성원소를 각각 측정하였다. 흡수된 규소는 잎으로 이동하여 모용(毛茸, trichome, hair)을 둘러싸고 있는 기부 세포에 축적되었다. 모용에서의 규소는 고농도의 칼슘 및 칼륨과 혼재하여 분포하였고, 저농도 처리시에는 모용기부를 제외한 표피세포에서는 감지 할 수 없는 수준으로 분포하였다. 잎에서의 규소 축적은 처리 후 24시간에서 48시간 사이에 세포벽 주위에 가장 많이 축적되었고, 그 이후에도 다소 증가하는 경향이었다. 처리된 규소는 발아하고 있는 흰가루병 분생포자의 인접 조직의 세포벽과 병원균 흡기 주변에 다량 축적되어 물리적인 장벽으로 작용하였다. 고농도의 규산 처리된 잎 병반상의 발아관 길이는 낮은 농도의 처리구와 비교하여 현저히 짧았으며, 규산 처리농도와 부의 상관관계를 나타내었다. 배양액내 처리된 규산 농도는 오이가 생장함에 따라 감소하여 뿌리를 통하여 작물체내로 흡수되었으며, 저농도 처리구(0.85 mM이하)에서는 흡수되는 양이 현저히 적었다.

• ALGAE
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• 제32권4호
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• pp.275-284
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• 2017

Microcystis aeruginosa causes harmful algal blooms in the Nakdong River of Korea. We studied the effect of different concentrations and ratios of ammonium ($NH_4{^+}$), nitrate ($NO_3{^-}$), and phosphate ($PO{_4}^{3-}$) on growth of this species in BG-11 medium: each nutrient alone, $NO_3{^-}:NH_4{^+}$ ratio, the N : P ratio with fixed total N (TN), and the N : P ratio with fixed total P (TP). The single nutrient experiments indicated that M. aeruginosa had the highest growth rate at $NH_4{^+}$ and $NO_3{^-}$ concentrations of $500{\mu}M$, and at a $PO{_4}^{3-}$ concentration of $5{\mu}M$. The $NO_3{^-}:NH_4{^+}$ ratio experiments showed that M. aeruginosa had the highest growth rate at a ratio of 1 : 1 when TN was $100{\mu}M$ and $250{\mu}M$, and the lowest growth rate at a ratio of 1 : 1 when the TN was $500{\mu}M$. The N : P ratio with fixed TN experiments indicated that M. aeruginosa had the highest growth rates at 50 : 1, 20 : 1, and 100 : 1 ratios when the TN was 100, 250, and $500{\mu}M$, respectively. In contrast, the N : P ratio with fixed TP experiments showed that M. aeruginosa had the highest growth rates at 200 : 1 ratio at all tested TP concentrations. In conclusion, our results imply that the $NO_3{^-}:NH_4{^+}$ ratio and the $PO{_4}^{3-}$ concentration affect the early stage of growth of M. aeruginosa. In particular, our results suggest that the maximum growth of M. aeruginosa is not simply affected by the $NO_3{^-}:NH_4{^+}$ ratio and the N : P ratio, but is determined by the TN concentration if a certain minimum $PO{_4}^{3-}$ concentration is present.

• 상하수도학회지
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• 제19권6호
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• pp.791-799
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• 2005

The phased isolation intra-clarifier ditch system used in this study is a simplified novel process enhancing simultaneous removal of biological nitrogen and phosphorus in municipal wastewater in terms of elimination of additional pre-anaerobic reactor, external clarifier, recycle of sludge, and nitrified effluent recirculation by employing intrachannel clarifier. Laboratory-scale phased isolation ditch system was used to assess the treatability on municipal wastewater. When the system was operated at the HRTs of 6~12hours, SRTs of 9~31days, and cycle times of 2~8hours, the system showed removals of BOD, TN, and TP as high as 88~97%, 70~84%, and 65~90%, respectively. The rainfall in Korea is generally concentrated in summer because of site-specific characteristics. Especially, the wet season has set in on June to August. In combined sewers, seasonal variations are primarily a function of the amount of stormwater that enters the system. In order to investigate the effect of hydraulic shock loading on system performance, the laboratory-scale system was operated at an HRT of 6hours (two times of influent flowrate) during two cycles (8hours). The system performance slightly decreased by increasing of influent flowrate and decreasing of system HRT. Nitrification efficiency and TN removal were slightly decreased by increasing of influent flowrate (decreasing of system HRT), whereas, the denitrification was not affected by hydraulic shock loading. However, the higher system performance could be achieved again after four cycles. Thus, the phased isolation technology for enhanced biological nutrient removal in medium- and small-scale wastewater treatment plants suffering fluctuation of influent quality and flowrate.

• 한국물환경학회지
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• 제20권6호
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• pp.563-570
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• 2004

Phased isolation intrachannel clarifier ditch process developed in this study is an enhanced biological nutrient removal process employing two ditches with intrachannel clarifiers. Bench-scale phased isolation ditch process was used to evaluate the system performance on municipal wastewater and detailed assessment of internal behavior in a ditch and each reactions. When the system was operated at the HRTs of 6~12hours, SRTs of 9~31 days, and cycle times of 4hours, the system showed removals of BOD, TN, and TP as high as 88~97%, 73~78%, and 65~90%, respectively. The internal behavior were well matched on each reactions such as nitrification, denitrification, and phosphorus release and uptake. As the SRT became longer, TN removal increased gradually, whereas TP removal decreased contrarily. However, the system was capable of producing an effluent TP concentration 1mg/L or less even at longer SRTs except the case of solids discharge by malfunction of intra-clarifier occurred by its geometrical limit. The system performance slightly decreased by hydraulic shock loading(increasing of influent flowrate and decreasing of system HRT). However, the higher system performance could be achieved again after four cycles. Thus, the system reliability could be successfully achieved short-term hydraulic shock loading that occurred in medium- and small-sized wastewater treatment plants suffering fluctuation of influent quality and flowrate during wet season.

• 한국미생물·생명공학회지
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• 제20권4호
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• pp.409-416
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• 1992

Bacillus cereus에 의한 pullulanase 생산의 최적 배양온도 및 배양시간은 각각 $15^{\circ}C$, 72시간이고, 기본배지에 casein, nutrient broth, egg albumin의 첨가는 효소의 생산을 크게 증가시켰다. 황산암모늄분획, CM-cellulose와 DEAE-cellulose column chromatography에 의하여 효소를 정제하였고 정제효소의 specific activity는 29.09U/mg protein, 수율은 17.1이었다. 정제효소는 polyacrylamide disc gel electrophoresis에 의하여 single band를 나타내었고, SDS-polyacrylamide disc gel electrophoresis에 의하여 추정된 분자량은 61,000, 등전점은 pH7.0, 최적온도는 $40^{\circ}C$, 최적 pH는 6.5, $35^{\circ}C$ 이하에서 안정하였고, pH 안정 범위는 6.5-11.0, $Ag^{+}$, $Hg^{2+}$, $Zn^{2+}$에 의하여 크게 저해되었고, $Ca^{2+}$은 효소의 내열성을 증가시켰다. 정제효소는 공시기질중 pullulan을 잘 분해시켰으며 pullulan에 대한 분해산물은 maltoriose이었다.

• 생물환경조절학회지
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• 제6권2호
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• pp.117-122
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• 1997

$25^{\circ}C$로 유지되고 있는 온실내에서 양액에 세라믹을 처리하여 청경채의 생장을 조사한 결과, 근권온도 3$0^{\circ}C$에서 가장 좋은 생장을 보였다. 특히 세라믹 2호는 각각의 온도 처리구에서 최고의 건물중이 나타난 반면, 3호는 무처리구보다도 오히려 생장이 억제되었다. 줄기와 뿌리의 건물중의 비는 온도가 높아짐에 따라서 증가되었고, 모든 세라믹 처리구에서는 감소되었는데, 이는 세라믹이 뿌리의 생장에 더 많은 영향을 주는 것으로 추정된다. 건물중 1g당 수분의 함량은 모든 세라믹 처리시 무처리구에 비하여 감소되었다. 1% 세라믹은 전기전도도가 0.001-0.03mS/cm으로 낮게 나타났다. 또한 세라믹 중에 파랑색을 띤 3호가 가장 항균력이 강했으며, 모든 세라믹은 물썩음 방지 효과가 있었다.

• 생명과학회지
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• 제17권7호통권87호
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• pp.983-989
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• 2007

Auxin, siderophore, 그리고 cellulase를 동시에 생산하는 생물방제균주 B. licheniformis Kll을 식물병원성진균을 대상으로 균사 성장억제능을 확인결과 6종의 식물병원성 진균에서 균사체 성장억제능을 확인하였으며, 그 중에서 토마토 시들음병을 유발하는 F. oxysporum(KACC 40037)에 가장 강력한 억제능을 나타내었다. 그리고 본 균주가 생산하는 항진균성 siderophore이외에 세포벽이 cellulose로 구성된 P. capsici의 cell wall을 분해하는 cellulase를 생산하는 것을 추가적으로 확인하였다. 뿐만아니라 B. licheniformis Kll은 nutrient broth(pH 8.0), $30{\circ}C$에서 96시간 배양시 토마토 시들음병에 대한 항진균 활성이 가장 높았고, 이는 cellulase의 활성과 sideropore의 최대 생산조건과는 상이하였다. 또한 탄소원과 질소원으로 starch와 urea를 각각 첨가시 항진균성 활성이 가장 높았고, 이 역시는 cellulase의 활성과 항진균성 siderophore의 최대 생산조건과 일치하지 않았다. 그리하여 본균주 B. licheniformis Kll은 식물성장촉진 물질은 auxin, 항진균성 siderophore와 cellulase를 생산함과 동시에 또 다른 강력한 항진균성 물질을 생산하는 것을 추가로 확인하였다.

• 대한지역사회영양학회지
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• 제3권4호
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• pp.642-654
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• 1998

In order to examine the television(TV)'s role of nutrition education and the nutritional interests and problems of the general public in the 1990s, a comtents analysis was done on two nutrition-related TV programs, a regular round-table talk show and a newscast. Broadcast from January 1993 to July 1997 and from January 1997 to July f1997, respectively. Nutrition-related information was classified into five categories. Food and nutrient(39.5%) and diseases(34.7%) were most frequently telecasted, which were followed by food habits and general health(13.0%), traditional dishes and cookery(8.2%), and food sanitation and safety(4.6%). In becoming the latest year, some trends in the issues displayed increased telecasts about disease, dish and cookery, and food safety, while the telecasting of food and nutrient decreased. The contents about the relations hip between life-style(including diet) and chronic degenerative diseases and the importance of balanced diets and regualr meals for health promotion became particularly emphasized. Overall, two TV programs provided the public with positive, practical, and sometimes practive nutrition education messages for improving eating life and health care. They also raised the public's awareness of the nutritional importance of Korean staple foods such as rice, kimchi, seaweed, and soysauce, and they sometimes satified the audience's curiosities by introducing Korean food culture or foods of Buddhist priests. When the accident of food toxicity occurred concrete information about how to manage it was rapidly given to the public. In addition they played a role in food balance policy by telecasting over-product foods such as garlic and onion. However some negative points appeared. Telecasts on milk and its products and diabetes mellitus showed the least frequently. These shows should be broadcast more often considering the present nutrition and health problems in Korea. Some functions or effects of foods were mostly explained by only physicians of Chinese medicine. Sometimes misinformed, unclear, overemphasized, biased, or unfair information was televised to the public. If these problems could be solved through the sincere cooperation between nutrition faculty and TV produces, become televison could a more complete and effective medium for educating the public about nutrition.

• 아시안잔디학회지
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• 제21권2호
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• pp.177-182
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• 2007

축구장의 식재지반이 모래로 조성될 경우 낮은 보비력과 높은 용탈율로 인해 시비관리의 조정이 필요하다. 본 실험의 목적은 PVC관을 이용한 경기장 유사모형 실험구에서 캔터키 블루그래스에 있어서 완효성비료의 생육 효과를 비교 실험하였다. 잔디의 색깔, 균일도, 생육, 지상부 생체량과배출수의 질산의 유출량을 몇 가지 다른 생육상과 네 번의 유사 강우 시험 시 행하였다. 실험 결과 요소의 성분 유출량이 가장 높았고 공시 완효성비료는 가장 낮았다. 이 완효성 비료는 다른 공시 잔디비료에 비해 14일간, 요소보다는 28일간 잔디의 품질 면에서 비효가 지속되었다. 또한 이 완효성비료는 잔디의 웃자람과 잔디깎기에 소요되는 시간을 줄일 수 있었다. 질산태 질소의 유출에 있어서도 잔디의 조성 초반기에 50% 정도를 감소 시켰다.

• Journal of Forest and Environmental Science
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• 제39권3호
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• pp.180-194
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• 2023

This study characterize, classify and evaluates the function of topography on spatial variability of some selected soil properties to assist in designing land management that support uniform agricultural production. The study site, an agricultural land, was part of the derived savanna zone in southwest Nigeria. Four soil profile pits each were established along two delineated toposequence and described following the FAO/UNESCO guidelines. Samples were collected from the identified genetic horizons. Properties of four soil series developed on different positions of the two delineated Toposequence viz upper, middle, lower slopes and valley bottom positions respectively were studied. The soil samples were analysed for selected physical and chemical properties and data generated were subjected to descriptive and inferential statistics. The results showed that soil colour, depth and texture varied in response to changes in slope position and drainage condition. The sand content ranged from 61 to 90% while the bulk density ranged between 1.06 g cm^-3 to 1.68 g cm^-3. The soils were neutral to very strongly acid with low total exchangeable bases. Available phosphorus value were low while the extractable micronutrient concentration varied from low to medium. Soils of Asejire and Iwo series mapped in the study area were classified as Typic isohyperthermic paleustult, Apomu series as Plinthic isohyperthermic paleustult and Jago series as Aquic psamment (USDA Soil Taxonomy). These soils were correlated as Lixisol, Plinthic Lixisol and Fluvisol (World Reference Based), respectively. Major agronomic constraints of the soils associations mapped in the study area were nutrient availability, nutrient retention, slope, drainage, texture, high bulk density and shallow depth. The study concluded that the soils were not homogenous, shows moderate spatial variation across the slope, had varying potentials for sustainable agricultural practices, and thus, the agronomic constraints should be carefully addressed and managed for precision agriculture.