• 제목/요약/키워드: BEC

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상업용(商業用) 원격탐사(遠隔探査)프로그램의 발달(發達) (THE DEVELOPMENT OF COMMERCIAL REMOTE-SENSING PROGRAMS)

  • Salin, Patrick A
    • 항공우주정책ㆍ법학회지
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    • 제4권
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    • pp.177-206
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    • 1992
  • Commercial remote-sensing is one of the applied fields of space activities which, like telecommunications but to a lesser extent, is in the process of recording a reapid rate of development. Fields of utilization for spatial imagery are numerous: ocean monitoring, crops monitoring, glaciology, meteorlogy, forestry, environmental watch, geology, etc. All those fields of interest could be gathered under the generic name of "earth-watching activities" which is somewhat larger than "remote-sensing." This article aims at presenting to Korean readers the main lines of development of five major players in the field, namely : the USA, France, Japan, Europe and Canada. This is not to exclude the role played by other active players such as the former USSR and other smaller though industrious space powers.

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사다리형 전자기 유도 투과에서의 초미세 구조 (Electromagnetically Induced Transparency with Hyperfine Structure)

  • 문한섭;이림;이원규;서호성;김중복
    • 한국광학회:학술대회논문집
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    • 한국광학회 2003년도 제14회 정기총회 및 03년 동계학술발표회
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    • pp.206-207
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    • 2003
  • 전자기 유도 투과(electromagnetically induced transparency ; EIT)는 원자의 공명 진동수를 갖는 조사광이 원자 매질을 통과할 때, 강한 결합광에 의한 효과로 매질에 흡수되지 않고 투과하는 양자 간섭 효과로써 원자결맞음 현상의 가장 대표적인 현상 중의 하나이다. EIT 현상은 Boller 등에 의해서 고출력 펄스 레이저를 이용하여 Strontium 증기에서 처음 관측된 이후, 여러 가지 원자와 분자의 증기 셀, 원자 빔, 고체, 냉각된 원자, 그리고 BEC(Bose Einstein condensate)상태에서 다양한 연구들이 이루어지고 있다. (중략)

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Steady-state Capabilities for Hydroturbines with OpenFOAM

  • Page, Maryse;Beaudoin, Martin;Giroux, Anne-Marie
    • International Journal of Fluid Machinery and Systems
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    • 제4권1호
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    • pp.161-171
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    • 2011
  • The availability of a high quality open source CFD simulation platform like OpenFOAM offers new R&D opportunities by providing direct access to models and solver implementation details. Efforts have been made by Hydro-Qu$\'{e}$bec to adapt OpenFOAM to hydroturbines for the development of steady-state capabilities. This paper describes the developments that have been made to implement new turbomachinery related capabilities: multiple frames of reference solver, domain coupling interfaces (GGI, cyclicGGI and mixing plane) and specialized boundary conditions. Practical use of the new turbomachinery capabilities are demonstrated for the analysis of a 195-MW Francis turbine.

Hydraulic Runner Design Method for Lifetime

  • Sabourin, Michel;Thibault, Denis;Bouffard, David-Alexandre;Levesque, Martin
    • International Journal of Fluid Machinery and Systems
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    • 제3권4호
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    • pp.301-308
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    • 2010
  • Quest for reliability of hydraulic runners is a concern for all mature electricity producers. The fatigue damage caused by dynamics loads is frequently the root cause of runner failure. This paper presents the damage tolerance approach based on fracture mechanics as the method chosen by Alstom and Hydro-Qu$\acute{e}$bec to predict effects of damage on runner lifetime and consequently to be use as a design method. This is sustained by a research on fracture mechanics properties of runner materials and by recommendations on the strategy to define a safety margin for design. The acquired knowledge permits to identify potential improvement of the runner lifetime without significant cost increase, like being more specific on some chemical composition or heat treatment.

방사선을 이용한 유착 방지용 수화겔 합성기술 개발 (Synthesis of Hydrogels for Prevention of Surgical Adhesions by Irradiation)

  • 노영창
    • 동위원소회보
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    • 제21권4호
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    • pp.46-54
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    • 2006
  • Biocompatible and biodegradable hydrogels based on carboxymethyl cellulose(CMC) and polyethyleneglycol(PEG) were prepared far physical barriers for preventing surgical adhesions. These interpolymeric hydrogels were synthesized by a gamma irradiation crosslinking technique. The 1Scmxl.Scm of cecal serosa and adjacent abdominal wail were abraded with bane burr until tbe serosal surface was disrupted and hemorrhagic but not perforated. and the serosa of tbe cecum was sutured to the abdominal wall in 5mm apart from the injured sire. The denuded cecum was covered with either CMC/PEG hydrogels or solution from CMC/PEG hydrogel. Control rat serosa was not covered. Two weeks later. the rats were sacrificed and adhesion was scored on a 0-5 scale. No treatment showed the significantly higher incidence of adhesions than either CMC/BEC hydrogels or solution from CMC/PEG hydrogel. In conclusion, these studies demonstrate that CMC/BEG hydrogels have a function of prevention of intra abdominal adhesion in a rat model.

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Low-Voltage-Stress AC-Linked Charge Equalizing System for Series-Connected VRLA Battery Strings

  • Karnjanapiboon, Charnyut;Jirasereeamornkul, Kamon;Monyakul, Veerapol
    • Journal of Power Electronics
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    • 제13권2호
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    • pp.186-196
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    • 2013
  • This paper presents a low voltage-stress AC-linked charge equalizing system for balancing the energy in a serially connected, valve-regulated lead acid battery string using a modular converter that consists of multiple transformers coupled together. Each converter was coupled through an AC-linked bus to increase the overall energy transfer efficiency of the system and to eliminate the problem of the unbalanced charging of batteries. Previous solutions are based on centralized and modularized topologies. A centralized topology requires a redesign of the hardware and related components. It also faces a high voltage stress when the number of batteries is expanded. Modularized solutions use low-voltage-stress, double-stage, DC-linked topologies which leads to poor energy transfer efficiency. The proposed solution uses a low-voltage stress, AC-linked, modularized topology that makes adding more batteries easier. It also has a better energy transfer efficiency. To ensure that the charge equalization system operates smoothly and safely charges batteries, a small intelligent microcontroller was used in the control section. The efficiency of this charge equalization system is 85%, which is 21% better than other low-voltage-stress DC-linked charging techniques. The validity of this approach was confirmed by experimental results.

귀비탕(歸脾湯)에 대한 방제학적(方劑學的) 연구(硏究) (A review on composition, action, compatibility of ingredients, clinicical application of Gwibitang)

  • 박양구;김윤경;윤용갑
    • 대한한의학방제학회지
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    • 제15권2호
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    • pp.1-8
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    • 2007
  • The source of Gwibitang(歸脾湯) is the book of Jesaebang(濟生方), The formulae is excluded Angelicae gigantis radix(當歸) and Polygalae radis(遠志) in the Jesaebang(濟生方), Jn the Guch iryuyo(口齒類要), Jeongcheryuyo(正體類要) and Gyojubuinyangbang(校註婦人良方), has been bec ame White Pria cocos Wolf(白茯笭) instead of Hoelen cum Pini Radix(白茯神), and is followed constitution of Uihagypmun(醫學入門) in the Donguibogam(東醫寶鑑). Basic formulae of Gwibitang(歸脾湯) consist of Sanjointang(酸棗仁湯), Sagunjatang(四君子湯). Hwanggitang, Danggwibohyeoltang(當歸補血湯), a kind of Jeongjihwan(定志丸類), a kind of Chongmyeongtang(聰明湯類). To deficiency of the heart and spleen, apply Sanjointang(酸棗 仁場), a kind of Jeongjihwan(定志丸), Sagunjatang(四君子湯) and Hwanggitang. To insufficiency of the spleen-gi(脾氣), apply Sagunjatang(四君子湯), Hwanggitang and a kind of Jeonssiigongsan(定志小丸). To deficiency of blood, apply Danggwibohyeoltang(當歸補血湯). Gwibitang(歸脾湯) is used for a mnesia and severe palpitation as a result of deficiency of the heart and spleen and deficiency of both gi(氣) and blood(血).

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Toxic Bile Salts-Induced Apoptosis of Hepatocytes in Biliary Obstruction Involves Fas-independent Pathway

  • Oh, Seon-Hee;Lee, Byung-Hoon
    • Toxicological Research
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    • 제19권1호
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    • pp.67-72
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    • 2003
  • Cholestatic liver injury results from the accumulation of toxic bile salts within the liver. The aim of the present study is to elucidate the changes in expression and cellular localization of apoptosis related proteins in the liver of bile duct-ligated (BDL) rat. Extrahepatic cholestasis was induced by double ligation of the common bile duct and cut between the ligatures. Animals were sacrificed at day 3 and at week 1, 2, 4, 6, and 8 after BDL. The number of TUNEL positive cells was increased significantly after 3 days of BDL, decreased over 2 weeks and remained constant thereafter. Fas expression was not changed and activation of caspase 8 did not occur. Fas immunoreactivity was exclusively observed in the cytoplasm of hepatocytes, indicating that Fas expressed in rat hepatocytes is a soluble form. Hepatocyte apoptosis was associated with Bax expression, which showed a peak at day 3 and decreased over time gradually. Immnunostaining of Bax was observed in hepatocytes and bile duct epithelial cells (BEC) of control and BDL rats. Bcl-2 was increased over time in BDL rats. These results suggest that apoptosis of hepatocytes in BDL rats is independent of Fas and controlled by Bax expression.

Cultivation of Spirulina platensis Using Pig Wastewater in a Semi-Continuous Process

  • Chaiklahan, Ratana;Chirasuwan, Nattayaporn;Siangdung, Wipawan;Paithoonrangsarid, Kalyanee;Bunnag, Boosya
    • Journal of Microbiology and Biotechnology
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    • 제20권3호
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    • pp.609-614
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    • 2010
  • The effluent from anaerobic digestion contains organic nitrogen and phosphorus, which are both required for growth of Spirulina platensis. Effluent (20%) from the upflow anaerobic sludge blanket (UASB) from a pig farm, supplemented with 4.5 g/l sodium bicarbonate ($NaHCO_3$) and 0.2 g/l urea fertilizer (46:0:0, N:P:K), was found to be not only a suitable medium for the growth of Spirulina platensis but also a low-cost alternative. Cost calculation showed that this medium is 4.4 times cheaper than modifized Zarrouk's medium. The average productivities of a semi-continuous culture grown under outdoor conditions in a 6-1 scale and a 100-1 pilot scale were 19.9 $g/m^2/d$ and 12 $g/m^2/d$, respectively. In addition, the biomass of organisms grown in UASB effluent contained approximately 57.9% protein, 1.12% $\gamma$-linolenic acid, and 19.5% phycocyanin. The average rates of bicarbonate, total nitrogen, and phosphorus removal were 380 mg/l/d, 34 mg/l/d, and 4 mg/l/d, respectively.

자가식세포작용: 천연물항암제로서의 신규작용기전 (Autophagy: Noble target mechanisms in natural medicines as anticancer agents)

  • 강세찬
    • Journal of Plant Biotechnology
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    • 제37권1호
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    • pp.57-66
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    • 2010
  • Programmed cell death systems are important for an active type of cell deaths. Among them, a type of programmed cell death, autophagy is activated in cancer cells in response to multiple stresses and has been demonstrated to promote tumor cell survival and drug resistance. Thus, in the area of cancer, over the time frame form around the 1940s to date, of the 155 small molecules, 73% are other than "synthetic", with 47% actually being either "natural products" or "directly derived therefrom". Autophagy has multiple physiological functions in multicellular organisms, including protein degradation and organelle turnover. Genes and proteins that constitute the basic machinery of the autophagic process were first identified in the yeast system and some of their mammalian orthologues have been characterized as well. Numerous oncogenes, including Akt1, Bcl-2, NF1, PDPK1, class I PI3K, PTEN, and Ras and oncosuppressors, inculuding Bec-1, Bif-1, DAPK-1, p53 and UVRAG suppress or promote the autophagy pathway. Regulation of autophagy in tumors is governed by similar principles of the normal cells, only in a much more complicated manner, given the frequently observed abnormal PI3K activation in cancer and the multitude of interactions between the PI3K/AKT/mTOR pathway and other cell signaling cascades, often also deregulated in tumor cells. Autophagy induction by some anticancer agents underlines the potential utility of its induction as a new cancer treatment modality of development for natural medicines.