• 제목/요약/키워드: Sand addition

검색결과 697건 처리시간 0.031초

감나무의 배 배양법에 의한 기내 증식 (In Vitro Propagation of Persimmon(Diospyros kaki) by Embryo Culture)

  • 박시원
    • KSBB Journal
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    • 제10권1호
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    • pp.15-22
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    • 1995
  • 감나무의 배를 대상으로 인공배지내에서 배배양을 시행하여 발아 및 생장을 시켰다$.$ Murashige­S Skoog(MS), Woody Plant Medium(WPM), C Campbell and Durzen(CD), Lictvay's Medium (LM), Kao-Michaluk(KM), Wolter-Skoog(WS), N Nitsch, White, Heller 배지 중에서 식물생장조절제 없이 배양을 시켰을 때 MS배지와 WPM배지에서 배양이 성공되어 발아와 생장이 잘 되어 $5.4{\pm}1.2 cm$의 신장과 5-6장의 잎을 가진 유묘가 형성되었다. 다음으로 식물생장조절제의 효과는 aUXin, c cytokinin, gibberllin류 중에 서 특히 gibberellin ($GA_3$)을 LM배지와 KM배지에 첨가했을 때 우수한 배양의 결과를 나타냈으며 최척농도는 $1~2{\mu}moles/\ell$ 이었다. 아울러 배배양과 자연파종에 의한 발아와 생장의 생리적 차이를 규명하고자 그 일환으로 식물 잎의 특정 효소인 superoxide dismutase(SOD) 활 성을 비교했을 때 특히 발아시기에 자연파종된 식물체의 SOD활성이 배양에 의한 식물체의 SOD활성보다 약 4배 이상 더 높았다.

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항만공사에 이용되는 널말뚝의 내진설계 (Seismic Design of Sheet Pile Walls Used in Harbor Construction)

  • 김홍택;방윤경;강인규;조원희
    • 대한토목학회논문집
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    • 제11권4호
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    • pp.171-187
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    • 1991
  • 본 연구에서는 항만공사에 이용되는 캔틸레버식 널말뚝 및 앵커로 지지된 널말뚝의 내진설계를 위한 해석방법의 제시가 이루어졌다. 제시된 해석방법은 침투에 의한 수압 및 유효수평응력의 변화를 고려하였으며, 또한 Mononobe-Okabe 토압이론 및 Westergaard, Matsuo-Ohara의 동수압 계산식이 적용되었다. 아울러 앵커로 지지된 널말뚝의 경우에 대해 안전율의 크기 선택에 관한 비교가 이루어졌으며, 또한 조밀한 모래지반의 경우에 대해, 준설저면의 경사각, 널말뚝 양쪽면의 수위차, 앵커의 위치, 벽마찰각 등이 근입깊이, 앵커하중 및 최대모멘트에 미치는 영향이 분석되었다. 이외에도 조밀한 모래지반에 설치되는 앵커로 지지된 널말뚝의 예비설계를 위한 표의 제시가 이루어졌으며, 본 연구 해석방법의 적용범위는 자유지지법의 경우로 한정된다.

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양재천에서 생태적 복원구간과 비복원구간에 서식하는 조류군집의 비교 (Comparison of Bird Communities Between Ecological Restoration Area and Non-restoration Area in the Yangjae Stream, Korea)

  • 김정수;구태회
    • 한국환경복원기술학회지
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    • 제8권4호
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    • pp.1-11
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    • 2005
  • Yangjae stream was divided with Seoul and Gwacheon reach. Seoul reach was ecologically restored; however, Gwacheon reach was not. Similarity index of the bird communities between the two areas was relatively high, 79.9%. The dominant species in Seoul reach were Passer montanus, Pica pica, Paradoxornis webbianus and Anas crecca. The dominant species in Gwacheon reach were Passer montanus, Pica pica, Paradoxornis webbianus and Streptopelia orientalis. The different species was Anas crecca in Seoul and Streptopelia orientalis in Gwacheon. An eco-park was constructed along the stream of Seoul reach since 1996 but was not in Gwacheon reach; the number of species has increased in Seoul area($r^2$=0.846, p<0.01), but Gwacheon was not change($r^2$=0.023, p>0.05) since 1996. The number of individuals, however, was almost constant in both reaches(Seoul : $r^2$=0.211, p>0.05, Gwacheon : $r^2$=0.032, p>0.05). In Seoul reach, the ecological restoration of stream was helpful to increase bird diversity. The number of waterbirds such as herons, plovers, sandpipers and wagtails was higher in Gwacheon reach than in Seoul reach, but the number of ducks and songbirds was higher in Seoul reach than in Gwacheon reach. We suggest that the ecological restoration in Seoul area might have negative effects on sandpipers, plovers and wagtails inhabiting on the flood plain in stream, but positive effects on other species such as herons, ducks and songbirds. Especially, the increasing number of ducks was attributed to an artificial pond in flood plain. The difference in the number of Streptopelia orientalis between both reaches was owing to the habitat differences such as forest trees playing a role as patch in high revetment. From the present investigation, it could be concluded that the ecological restoration of the local stream must be carried out with consideration of water channels, sand banks and water front in addition to the high revetment for birds to attract diverse bird communities.

유아(幼兒)의 놀이복 디자인 개발 연구 (Design Development for Toddler's Playwear)

  • 이연희;박혜원
    • 한국의류학회지
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    • 제33권8호
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    • pp.1227-1240
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    • 2009
  • This study examines the actual conditions of toddler playwear preference survey for design and function. The study develops proper indoor and outdoor playwear for toddlers based on the analysis. A survey of 200 parents with toddlers between 2 and 6 years old and 120 teachers was conducted to find the conditions and needs for playwear along with the necessary design elements. Second, 6 designs including 3 designs for indoor playwear and 3 designs for outdoor playwear were made. These designs emphasized on soil contamination part, color, pattern, form, material, detail, and fasteners. Art play and cooking play are considered for indoor playwear and ways to decrease contamination on sleeve hem, elbow, chest, and knee were determined through the use of yellow, green, and blue colors. Applying a character and separate top with sleeves were determined. Light with breathable and waterproof fabric was determined. The correct amount of Velcro fasteners or buttons was determined for front fastening in addition a pocket was considered necessary as a detail part. The common design for both boys and girls along with a proper design for diverse play were determined. For outdoor playwear, water play, sand play, movement play, and ecology experience are considered and ways to decease contamination on hip, sleeve hem, and knee should be applied to the design as determined through the use of yellow, green, blue, and red colors. The demands for pattern, form, material, and details were similar to indoor playwear. Zipper and buttons for front fastening were determined. These final 6 playwear designs are presented using CAD WALK DESIGNWARE.

어린이용 자전거의 차량 충돌거동에 관한 연구 (A Study on the Collision Behavior of Fairy Cycle to Vehicle)

  • 강대민;안승모
    • 한국자동차공학회논문집
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    • 제20권1호
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    • pp.106-111
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    • 2012
  • Recently the usage of bicycle has increased steeply in Korea owing to traffic culture of well- being. In a car to bicycle accident investigation, the throw distance of bicycle is very important factor for reconstructing of the accident. The variables that influence on the throw distance of bicycle can be classified into the factors of vehicle and bicycle. Simulations and collision tests in actual car to bicycle accident were executed for obtaining throw distance of bicycle. The simulations were done by PC-$CRASH^{TM}$ and for actual crash tests sand bags were used for the behavior of bicyclist instead of dummy. Factors considered were vehicle velocity and the moving angles of bicycle, also the types of bicycle and vehicle were fairy cycle and automobile, respectively. From the results, the throw distances of a head-on tire collision of $0^{\circ}$ direction was longer than that of tire crash test of $45^{\circ}$ direction, and the throw distances of a head -on frame crash test of $90^{\circ}$ direction was longer than that of frame crash test of $45^{\circ}$ direction. In addition restitution coefficient between vehicle and bicycle was estimated as about 0.1 with based on actual crash tests. Finally the increaser vehicle velocity the longer the throw distances of bicycle, and the results of simulation were relatively good agreement to the experimental results.

Characterization of Bacillus luciferensis Strain KJ2C12 from Pepper Root, a Biocontrol Agent of Phytophthora Blight of Pepper

  • Kim, Hye-Sook;Sang, Mee-Kyung;Myung, Inn-Shik;Chun, Se-Chul;Kim, Ki-Deok
    • The Plant Pathology Journal
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    • 제25권1호
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    • pp.62-69
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    • 2009
  • In this study, we characterized the bacterial strain KJ2C12 in relation with its biocontrol activity against Phytophthora capsici on pepper, and identified this strain using morphological, physiological, biochemical, fatty acid methyl ester, and 16S rRNA gene sequence analyses. Strain KJ2C12 significantly (P=0.05) reduced both final disease severity and areas under the disease progress curves of 5-week-old pepper plants inoculated with P. capsici compared to buffer-treated controls. As for the production of antibiotics, biofilms, biosurfactant, extracellular enzyme, HCN, and swarming activity, strain KJ2C12 produced an extracellular enzyme with protease activity, but no other productions or swarming activity. However, Escherichia coli produced weak biofilm only. Strain KJ2C12 could colonize pepper roots more effectively in a gnotobiotic system using sterile quartz sand compared to E. coli over 4 weeks after treatments. However, no bacterial populations were detected in 10 mM $MgSO_4$ buffer-treated controls. Strain KJ2C12 produced significantly higher microbial activity than the $MgSO_4$-treated control or E. coli over 4 weeks after treatments. Bacterial strain KJ2C12 was identified as Bacillus luciferensis based on morphological, physiological, and biochemical characteristics as well as FAME and 16S rRNA gene sequence analyses. In addition, these results suggested that B. luciferensis strain KJ2C12 could reduce Phytophthora blight of pepper by protecting infection courts through enhanced effective root colonization with protease production and an increase of soil microbial activity.

산화-막여과에 의한 망간 제거 시 과망간산과 차아염소산 복합 주입의 효과 (Multiple injection of permanganate and hypochlorite for manganese removal by oxidation combined with membrane filtration)

  • 곽효은;박정원;민소진;임주완;김기홍;이호성;남창현;박용민;박병규
    • 상하수도학회지
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    • 제32권3호
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    • pp.211-220
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    • 2018
  • The water containing soluble manganese may cause problems such as discolored water, unpleasant taste, fouling or scaling of pipes in water distribution system, and so on. Conventional water treatment processes using sand filtration or sedimentation after oxidation, however, cannot often meet manganese standard for drinking water. Two types of oxidants, potassium permanganate ($KMnO_4$) and sodium hypochlorite (NaOCl), were utilized at the same time for manganese oxidation, and then the precipitated manganese oxides were removed by low pressure membrane filtration in this study. In batch experiments, the multiple injection of both oxidants showed more effective manganese removal than did the single injection using either of them. Moreover, the deterioration of manganese removal at low temperature was less serious for the multiple injection than that for the single injection. Manganese removal by the continuous system of oxidation by multiple injection combined with membrane filtration was higher than those by batch experiments at the same oxidation conditions. In addition, less membrane fouling was observed for membrane filtration with oxidation during continuous membrane filtration than membrane filtration without oxidation. These results indicate that the oxidation by multiple injection coupled with membrane filtration was efficient and applicable to actual water treatment for manganese removal.

평림천 어류군집에 관한 연구 - 평림댐 상·하류 수질 및 하천건강성평가와 함께 - (A Study on Fish Community in Pyeonglim Stream - with Water Quality and Stream Health Assessment in Up- and Downstream of Pyeonglim Dam -)

  • 서진원
    • 환경영향평가
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    • 제18권3호
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    • pp.151-160
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    • 2009
  • In order to use fundamental data for conservation of species diversity and stream health with dam development, fish investigation in up- and downstream of Pyeonglim Dam was seasonally conducted in 2007~2008. In addition, data of water qualities, investigated for environmental impact assessment, were used to determine a water quality standard level in Pyeonglim Stream, and it revealed that water environment condition was good in the stream. During the study period, a total number of fish caught from the 4 study sites was 5,449 representing 9 families 25 species, and there were 8 Korean endemic species (32.0%) including Rhodeus uyekii, Squalidus gracilis majimae, and Microphysogobio yaluensis. Two species of Zacco temminckii (37.5%) and Zacco platypus (26.3%) were dominant and subdominant in all sites. There were few individuals of the $2^{nd}$-class endangered species (Sand lamprey, Lampetra reissneri) and the introduced species (Bluegill, Lepomis macrochirus), found in the upstream of the dam. and further investigation for conservation of the endangered species and for prevention of the introduced species is needed in future. With fish fauna and multi-metric health assessment model in each sampling attempt, index of biotic integrity(IBI) was evaluated and it resulted mostly in good(26~35) and excellent(36~40) condition in all sites. The results indicate that it is very important to study not only environmental impact assessment with fish composition but also stream health assessment in order to conserve healthy aquatic ecosystem.

복잡한 해안선 구조를 가진 통영 해역에서 조하대 저서생물 군집의 공간특성 비교 (Discussion to Spatial Characteristics on a Sub-tidal Benthic Community Composed to the Complicated Coastal Lines Around Tongyeong, Korea)

  • 윤건탁;정윤환;강래선
    • Ocean and Polar Research
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    • 제32권2호
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    • pp.123-135
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    • 2010
  • Around Tongyeong coasts which located in southern coast of Korea composed to the complex coastal line and scattered by small islands. It also has been distributed to a complicated bathymetric structure by several types of channels. This study carried to analyze the spatial characteristics of macrobenthic community and benthic environmental variance on sub-tidal area based on multivariate statistics tools. Sediment composition varied from muddy sand to mud, and along the channels, it composed to a heterogeneous bottoms mixed by shell fragment, cobbles and mud. Organic contents on the surface sediment varied 1.1-3.9%. Total of 272 species, $33,349\;ind./m^2$ of macrobenthos identified in all of sample area. Polychaetes also prevailed among the specimen. L. longifolia, P. pinnata dominated based on density. Considering on the biomass, echinoderm S. lacunosa, A. tricoides listed. Closer to the coastal area, the density and diversity were higher. Community structure based on cluster analysis was discriminated into three groups. Each group was also characterized by geographical state such as depth, sediment composition. In addition, when applied to the bathymetric data, the channel, which composed to the mixed sediment, made a role of limited factor which characterized to benthic community. Because the specimen around the channel have been affected on the diverse sediment mixture. Most of benthic studies in the southern coast of Korea focused to the condition of benthic organic pollution spatially, because along the coast, it also developed a aquaculture ground and industrial complex. But, as results, most of the area, it turn out the less polluted areas nevertheless similar environment situation. It supposed that benthic community affect to the bottom sediment composition by physical characteristics.

열가수분해 반응을 이용한 조류인플루엔자(AI) 감염 가금류의 사체처리 및 연료화 (Disposal and Waste-to-Fuel of Infected Poultry with Avian Influenza(AI) Using Thermal Hydrolysis Reaction)

  • 송철우;김남찬;정국;류재근
    • 유기물자원화
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    • 제24권4호
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    • pp.49-57
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    • 2016
  • 본 연구에서는 열가수분해 기술을 이용하여 AI 발생으로 인해 살처분된 가금류 사체를 처리하고 연료화 가능성을 판단하고자 하였다. 실험결과 가금류 사체는 일부 모래를 제외하고 모두 액상화 되었으며, 운전온도 $190^{\circ}C$, 운전시간 60분에서 최적효율을 나타냈다. 열가수분해 후 발생한 액상생성물은 탄소 함유량과 발열량이 높고 회분의 함량이 낮아 연료화 하기에 좋은 조건을 가지고 있는 것으로 나타났다. 또한 별도의 보조연료 투입 없이 연소 시 발생하는 폐열만을 활용해 열가수분해 설비를 운전하는 것이 가능하였으며, 연소 시 발생하는 배출가스는 대기에 미치는 영향은 적은 것으로 나타났다.