• 제목/요약/키워드: K-Ras

검색결과 605건 처리시간 0.037초

친환경 소하천의 수리적 안정성 분석에 관한 연구 (A Study on Hydraulic Stable Analysis of The Natural Small River)

  • 김태경;이경훈;선병진;최천호
    • 환경영향평가
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    • 제16권3호
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    • pp.187-194
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    • 2007
  • It started road constructions around river in 1990s. These maintenances concentrate on city river. Because river lives no living things and men don't come near there. But in spite of these river environment go to rack, river maintenances still keep on using preexistence method since 1990s. Only a part of city river environment maintenances consider environmental ability of passive river, river maintenance of a purpose of flood control still don't consider in the concrete. Because propulsion device that consider environment ability of passive river and possible application techniques don't complete. In accordance, A natural river maintenance needs absolutly a series of river projects. Because a natural river maintenance prevents a damage of environment ability. This study is to assume the flood really happened and to carry out the flood damage simulation needed in overflow simulation about the inundated zone. Also, This study examine unstable part about the hydraulic characteristic as velocities, stream power, shear, hydraulic depth, flow area in basin. And this study applied the HEC-RAS(river analysis system) model to predict flood overflow in youngsan river basin. Project flood is used the return period 100 year and inputed data that was calculated in intensity figures of illumination.

In-situ Synthesis of Cu-TiB2 Nanocomposite by MA/SPS

  • Kwon, Young-Soon;Kim, Ji-Soon;Kim, Hwan-Tae;Moon, Jin-Soo;D.V Dudina;O.I. Lomovsky
    • 한국분말재료학회지
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    • 제10권6호
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    • pp.443-447
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    • 2003
  • Nano-sized $TiB_2$ was in situ synthesized in copper matrix through self-propagating high temperature synthesis (SHS) with high-energy ball milled Ti-B-Cu elemental mixtures as powder precursors. The size of $TiB_2$ particles in the product of SHS reaction decreases with time of preliminary mechanical treatment ranging from 1 in untreated mixture to 0.1 in mixtures milled for 3 min. Subsequent mechanical treatment of the product of SHS reaction allowed the $TiB_2$ particles to be reduced down to 30-50 nm. Microstructural change of $TiB_2$-Cu nanocomposite during spark plasma sintering (SPS) was also investigated. Under simultaneous action of pressure, temperature and electric current, titanium diboride nanoparticles distributed in copper matrix move, agglomerate and form a interpenetrating phase composite with a fine-grained skeleton.

신동맥 색전술로 치료한 신혈관 고혈압증 1례 (A Case of Renovascular Hypertension Controlled by Renal Artery Embolization)

  • 유정훈;김영득;신병석;길홍량
    • Clinical and Experimental Pediatrics
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    • 제48권2호
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    • pp.212-215
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    • 2005
  • 신성 고혈압은 소아기 이차성 고혈압의 흔한 원인이며, 그 중 신동맥 협착은 치료 가능한 고혈압의 가장 흔한 원인이다. 신혈관성 고혈압 치료로 약물치료에 반응하지 않는 경우 혹은 초기 단계부터 치료목적으로 경피적 혈관 성형술과 신장동맥 스텐트 등의 중재적 혈관 성형술이나 수술요법이 시행할 수 있다. 죽상 경화형 협착, 다발성의 협착, 미세동맥류, 그리고 협착 부위가 혈관 성형술이나 stent로 교정되기 어려운 경우에는 부분적 혹은 완전 신장동맥 색전술이 시도될 수 있다. 저자들은 신장동맥 색전술을 이용한 renal ablation요법으로 고혈압의 호전을 보인 신혈관 고혈압증 1례를 경험하였기에 보고하는 바이다.

Fabrication of Microcrystalline NaPbLa(WO4)3:Yb3+/Ho3+ Phosphors and Their Upconversion Photoluminescent Characteristics

  • Lim, Chang Sung;Atuchin, Victor V.;Aleksandrovsky, Aleksandr S.;Denisenko, Yuriy G.;Molokeev, Maxim S.;Oreshonkov, Aleksandr S.
    • 한국재료학회지
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    • 제29권12호
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    • pp.741-746
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    • 2019
  • New triple tungstate phosphors NaPbLa(WO4)3:Yb3+/Ho3+ (x = Yb3+/Ho3+ = 7, 8, 9, 10) are successfully fabricated by microwave assisted sol-gel synthesis and their structural and frequency upconversion (UC) characteristics are investigated. The compounds crystallized in the tetragonal space group I41/a and the NaPbLa(WO4)3 host have unit cell parameters a = 5.3927(1) and c = 11.7961(3) Å, V = 343.05(2) Å3, Z = 4. Under excitation at 980 nm, the phosphors have yellowish green emissions, which are derived from the intense 5S2/5F45I8 transitions of Ho3+ ions in the green spectral range and strong 5F55I8 transitions in the red spectral range. The optimal Yb3+:Ho3+ ratio is revealed to be x = 9, which is attributed to the quenching effect of Ho3+ ions, as indicated by the composition dependence. The UC characteristics are evaluated in detail under consideration of the pump power dependence and Commission Internationale de L'Eclairage chromaticity. The spectroscopic features of Raman spectra are discussed in terms of the superposition of Ho3+ luminescence and vibrational lines. The possibility of controlling the spectral distribution of UC luminescence by the chemical content of tungstate hosts is demonstrated.

소유역의 토사유실량에 따른 유사저류지 설계적정성 검토 (Optimum Scale Evaluation of Sedment Basin Design by Soil Erosion Estimation at Small Basin)

  • 이상진;최현;곽영주;이배성
    • 대한공간정보학회지
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    • 제15권2호통권40호
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    • pp.25-31
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    • 2007
  • 최근 빈번하게 발생하는 집중호우는 지표면의 침식을 가중시켜 막대한 양의 토사유출을 초래하고 있으며, 이렇게 유실된 토사는 하천의 통수단면을 감소시키고 탁수를 유발하는 등의 환경문제의 원인이 되고 있다. 본 연구에서는 유사저류지의 규모의 적정성을 검토하기 위하여 지형정보자료를 활용하여 범용토양유실공식을 적용한 후 소유역의 토사유실량(Soil Erosion)을 분석하고 저류지 용적규모와 비교 평가하여 유사저류지 규모의 적정성을 검토하였다. 분석결과 대상유역의 토사유실량 및 설계퇴적량은 각각 $72.1m^3$$85.0m^3$로 산정되어 유사저류지 규모는 적정한 것으로 분석되었다. 또한 Hec-Ras모형을 이용하여 수위상승으로 인한 제내지의 침수피해를 방지하기 위한 제방고를 산정하여 유사저류지의 수리학적 안정성을 평가하였다.

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Pro-tumorigenic roles of TGF-β signaling during the early stages of liver tumorigenesis through upregulation of Snail

  • Moon, Hyuk;Han, Kwang-Hyub;Ro, Simon Weonsang
    • BMB Reports
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    • 제50권12호
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    • pp.599-600
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    • 2017
  • Many studies have focused on the tumor suppressive role of $TGF-{\beta}$ signaling during the early stages of tumorigenesis by activating the target genes involved in cytostasis and apoptosis. We investigated the effects of $TGF-{\beta}$ inhibition on early tumorigenesis in the liver, by employing diverse inhibitory methods. Strikingly, $TGF-{\beta}$ inhibition consistently suppressed hepatic tumorigenesis that was induced either by activated RAS plus p53 downregulation or by the co-activation of RAS and TAZ signaling; this demonstrates the requirements for canonical $TGF-{\beta}$ signaling in tumorigenesis. Moreover, we found that Snail is the target gene of the $TGF-{\beta}$ signaling pathway that promotes hepatic carcinogenesis. The knockdown of Snail suppressed the early tumorigenesis in the liver, as did the $TGF-{\beta}$ inhibition, while the ectopic expression of Snail restored tumorigenesis that was suppressed by the $TGF-{\beta}$ inhibition. Our findings establish the oncogenic $TGF-{\beta}$-Smad-Snail signaling axis during the early tumorigenesis in the liver.

DIRECT SUM, SEPARATING SET AND SYSTEMS OF SIMULTANEOUS EQUATIONS IN THE PREDUAL OF AN OPERATOR ALGEBRA

  • Lee, Mi-Young;Lee, Sang-Hun
    • 대한수학회보
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    • 제31권2호
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    • pp.173-180
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    • 1994
  • Let H be a separable, infinite dimensional, compled Hilbert space and let L(H) be the algebra of all bounded linear operators on H. A dual algebra is a subalgebra of L(H) that contains the identity operator $I_{H}$ and is closed in the ultraweak topology on L(H). Note that the ultraweak operator topology coincides with the wea $k^{*}$ topology on L(H)(see [3]). Bercovici-Foias-Pearcy [3] studied the problem of solving systems of simultaneous equations in the predual of a dual algebra. The theory of dual algebras has been applied to the topics of invariant subspaces, dilation theory and reflexibity (see [1],[2],[3],[5],[6]), and is deeply related with properties ( $A_{m,n}$). Jung-Lee-Lee [7] introduced n-separating sets for subalgebras and proved the relationship between n-separating sets and properties ( $A_{m,n}$). In this paper we will study the relationship between direct sum and properties ( $A_{m,n}$). In particular, using some results of [7] we obtain relationship between n-separating sets and direct sum of von Neumann algebras.ras.s.ras.

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Hematological and histological changes of black porgy Acanthopagrus schlegeli in ozonated recirculating systems

  • Kim, Pyong-Kih;Kim, Jae-Won;Park, Jeonghwan
    • Fisheries and Aquatic Sciences
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    • 제21권1호
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    • pp.2.1-2.8
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    • 2018
  • This study evaluated hemato-histological changes of black porgy in recirculating aquaculture systems (RAS) with three different ozone doses (no ozone, 20 g, and $40g\;ozone/kg\;feed\;day^{-1}$). During the 44-day study, black porgy did not show significant behavior changes or mortalities in both the ozonated systems displaying average total residual oxidants concentrations of 0.12 and 0.25 mg/L. There were no differences in growth and blood parameters among the systems. However, histological alterations on gills and livers were observed in both the treatment systems. In the higher ozone dose, signs of cellular damage were more apparent. Although the ozone doses did not manifest a serious adverse effect on growth and hematological observations in this short-term study, an ozone dose should not exceed $20g\;ozone/kg\;feed\;day^{-1}$ for black porgy based on the histological result. In order to use ozone in a seawater RAS, further studies will be needed to evaluate long-term effects of total residual oxidants.