• Title/Summary/Keyword: 근반응성

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A Numerical Study on the Heat and Fluid Flow in Steam Reforming Reactor (수증기 개질 반응로에 대한 열유동 해석)

  • Han, Jeongok;Lee, Joongseong;Lee, Yeongcheol;Hong, Seongho;Hong, Sungkook;Dong, Sangkeun
    • Journal of the Korean Institute of Gas
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    • v.17 no.2
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    • pp.78-84
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    • 2013
  • A numerical study on the heat and fluid flow has carried out for the design of the steam reforming reactor which consists of six reforming tubes and one burner. Reforming reaction calculation is coupled with the heat and fluid flow one. The burner type in the reforming reactor is chosen through the fluid flow calculation according to different type of burner structure. It is shown that the significant temperature gradient exists in the reforming reactor, affecting the component variation along the length of reforming tube. The component ratio of reforming gas is changed by the variation of SCR and GHSV.

A Study on the Spinnability of Oxi-PAN Staple Fiber (Oxi-PAN Staple Fiber 의 방적성에 관한 연구)

  • 이유근;박종규;강태전
    • Proceedings of the Korean Fiber Society Conference
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    • 2001.10a
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    • pp.279-282
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    • 2001
  • Oxi-PAN(Oxidized PAN, Oxi-PAN)섬유는 PAN 섬유를 1-2$^{\circ}C$/min정도의 승온 속도로 180-30$0^{\circ}C$ 정도의 저온, 산화 분위기에서 인장력을 가한 상태로 열처리하여 얻는 섬유이며, 이 열처리 과정 중에 PAN 섬유의 분자쇄에서는 Cyclization, Dehydrogenation 및 산화 반응이 일어나게 된다. 이렇게 제조된 Oxi-PAN 섬유는 탄소섬유의 프리컷(Precursor)로 사용되기도 하고 또한 열안정성이 뛰어나 내염화섬유용으로 사용되기도 한다. (중략)

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Malignant Solitary Fibrous Tumor of the Pleura -one case report- (늑막의 악성 고립성 섬유성 종양 -1례 보고-)

  • 이희성;지현근;홍기우;안현성;박혜림
    • Journal of Chest Surgery
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    • v.34 no.1
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    • pp.97-100
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    • 2001
  • 흉막의 고립성 섬유성 종양은 중피하에 존재하는 미분화 중배엽성 기원의 섬유 세포에서 기원하는 종양으로 알려졌다. 이 종양은 대부분 양성으로 보고되고 있으나 병리학적으로 높은 세포 밀도, 유사분열의 수가 많고(10개의 고배율 시야에서 4개 이상), 핵의 다양성, 출혈, 괴사등이 있으며 악성의 판단기준으로 보고된다. 환자는 62세 여자로 호흡곤란 및 기침을 주소로 본원에 입원하였으며 단순 흉부 방사선 및 전산화 단층 촬영상 우측 흉강내에 거대한 종양소견이 보였다. 이 종양은 23$\times$18$\times$12 cm, 2 kg의 크기와 무게를 가졌으며 우측폐 하엽과 중엽은 압박되어있었으나 종양 절개 후 재 팽창됨을 확인하였다. 또한 횡경막과 심하게 유착되어 박리도중 손상이 동반되어 봉합술이 필요하였다. 병리학적으로 종괴는 세포밀도가 높았고 방추형세포의 다발로 이루어져 있었으며 유사분열의 수가 많이(27 mitosis/10HPF)보였다. 면역 조직 화학 검사상 vimentin과 CD34에 양성 반응을 보였다. 이에 악성 고립성 섬유성 종양으로 확진되었다. 본 교실에서는 흉막에 발생한 악성 고립성 섬유성 종양을 치험하였기에 문헌 고찰과 함께 보고한다.

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Cellular Pathways in Agonist-induced Gallbladder Muscle Contraction in the Cat (고양이의 담낭근 수축에 있어서 세포내 기전)

  • Rhim, Byung-Yong;Kim, Chi-Dae;Kim, Dong-Heon;Biancani, Piero;Behar, Jose
    • The Korean Journal of Pharmacology
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    • v.32 no.1
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    • pp.67-74
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    • 1996
  • Cholecystokinin octapeptide (CCK-8), acetylcholine (ACh) and KCl caused a dose dependent contraction in muscle cells enzymatically digested from cat gallbladder. Maximal contraction was obtained at concentration of $10^{-9}M$ for CCK-8, $10^{-5}M$ for ACh and 20mM for KCl. CCK-8 induced contraction was unaffected in calcium free physiological salt solution (PSS) and was completely blocked by strontium substitution for calcium (p<0.001). In contrast, KCl evoked contraction was blocked in calcium free PSS (p<0.01) but was unaffected by strontium replacement of calcium. The contraction elicited by ACh was only slightly reduced in calcium free PSS (p<0.05) and was unaltered by strontium. Muscle cells permeabilized with saponin contracted in response to inositol 1,4.5-trisphosphate $(IP_3)$ and CCK-8. The contraction was blocked by the calmodulin antagonist CGS 9343B (p<0.001), whereas heparin completely blocked the effect of $IP_3$ (p<0.001). The protein kinase C (PKC) antagonist H7 had no effect on either agonist. We conclude that CCK-8 induced gallbladder muscle contraction is mediated by $IP_3$ dependent intracellular calcium release from intracellular stores and a calmodulin dependent pathway; ACh may utilize both extracellular and intracellular calcium. KCl causes muscle contracrion through influx of extracellular calcium and a calmodulin independent machanism.

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Effects of Isokinetic Exercise on the Composition of Muscle Fibers in Rats Lower Limb (등속성 운동이 흰쥐 하퇴의 근섬유조성에 미치는 영향)

  • Lee, Yong-Deok;Cho, Hyun-Gug;Kim, Han-Soo;Park, Youn-Ki;Suh, Tae-Soo
    • The Journal of Korean Physical Therapy
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    • v.3 no.1
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    • pp.75-90
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    • 1991
  • This study is to characterize the effects of swimming exercise on the composition of muscle fibers in rats lower limb tissue. By comparing the exercised group (4, 8 weeks) with the control group, we analyzed the difference histologically, histochemically and morphometrically. The obtained results are as follows ; 1. In the histological view, the distance between the individual muscle fibers and the muscle bundles in exercised group was shorter than that of control group. The irregular shape of sarcolemma in exercised group was observed. 2, In the histochemical view(NADH-TR. and Myosin ATPase reaction analysis), the increased populations of red and intermediate fibers were observed, whereas the white fiber was decreased. 3. In the morphometrical view, the red and intermediate fibers of tibialis anterior and gastrocnemius in exercised group were quantitatively increased, compared with control group. However, the white fiber and connective tissue in exercised group were decreased.

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Selectivity Changes in CO Hydrogenation over Potassium Added Titania-supported Cobalt Catalysts (티타니아 담지 코발트 촉매를 이용한 일산화탄소 수소화 반응에서 칼륨첨가에 의한 선택성 변화)

  • Lee, Dong-Keun;Ahn, Jou-Hyeon
    • Applied Chemistry for Engineering
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    • v.1 no.1
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    • pp.100-105
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    • 1990
  • Small amounts of potassium were added to the titania - supported cobalt catalysts in order to produce higher and olefinic hydrocarbons in CO hydrogenation. Titania and potassium played important roles not only for the enhancement of the production of higher and olefinic hydrocarbons, but also for the prevention of the catalyst deactivation by carbon deposits. Titania support induced the so - called SMSI, and potassium seemed to act as an electronic modifier, giving rise to an electron enrichment of the metallic phase.

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Studies on the amino acid metabolism of young rice root (Part 4) -Properties of glutamic oxalacetic transaminase isozymes of rice root- (수도근(水稻根)의 Amino 산(酸) 대사(代謝)에 관(關)한 연구(硏究) -제(第) 4 보(報) 수도근(水稻根)의 Glutamic Oxalacetic Transaminase Isozyme의 성질(性質))

  • Kim, Kwang Sik;Kim, Young Ung
    • Korean Journal of Soil Science and Fertilizer
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    • v.7 no.4
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    • pp.209-213
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    • 1974
  • The isozymes of glutamic oxalacetic transaminase from young rice root were isolated by DEAE-cellulose column chromatography, and investigated some of their enzymic properties. Obtained results were summarized as follows: 1. 93 percent of GOT activity in rice root existed in supernatant fraction, and their specific activity exibited the same pattern. 2. The rice root contained two types of GOT isozyme; cationic and anionic GOT. It seemed that both of them were distributed in supernatant fraction. 3. GOT isozymes of rice root on the pH dependance showed their maximum activity at 7.4. 4. On the stability of GOT isozymes for temperature, anionic GOT was more unstable than cationic GOT. 5. Apparent Michaelis constant for L-aspartate of GOT isozymes from rice root showed 12-14mM in the cationic GOT and 16mM in the anionic GOT, respectively.

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Existence of Cholinergic and Purinergic Receptor on the Detrusor Muscle of Rat Urinary Bladder (흰쥐 적출 배뇨근에서 콜린성 및 퓨린성 수용체의 존재)

  • Choi, Tae-Su;Kwon, Oh-Cheol;Ha, Jeoung-Hee;Lee, Kwang-Youn;Kim, Won-Joon
    • Journal of Yeungnam Medical Science
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    • v.8 no.2
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    • pp.138-149
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    • 1991
  • This study was aimed at investigation of the stimulatory innervations on the rat urinary bladder. Detrusor muscle strips of 15 mm long were suspended in isolated muscle chambers containing 1 ml of PSS maintained at $37^{\circ}C$ and aerated with 95% $O_2/5%CO_2$. Isometric myography was perfomed, and the results were as followings : Muscle strips showed "on-contraction" by electric field stimulation (EFS) frequency-dependently. The EFS-induced contraction was not affected by hexamethonium, a ganglion blocker, but abolished, by tetrodotoxin, a nerve conduction blocker. Physostigmine, a cholinesterase inhibitor enhanced the EFS-induced contraction which was inhibited by hemicholinium, an inhibitor of choline uptake at the cholinergic nerve ending. Such an EFS-induced contraction was antagonized by atropine only partially, and the atropine-resistant portion was completely abolished by the desensitization of purinergic receptors by prolonged incubatin of the strips in the presence of high concentratin of ATP. Bethanechol, a cholinergic agonist, elicited concentration-dependent contraction. Adenosine triphosphate (ATP), a purinergic agonist, induced a weak but concentration-dependent contraction of short duration. Bethanechol-induced contraction was not affected by ATP-desensitization, and ATP-induced contraction was not affected by tetrodotoxin. These results suggest that there are at least two main stimulatory components of innervations in the detrusor muscle, cholinergic muscarinic and purinergic ; and those receptors are independent each other.

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The analysis of EU carbon trading and energy prices using vector error correction model (벡터오차수정모형을 이용한 유럽 탄소배출권가격 분석)

  • Bu, Gi-Duck;Jeong, Ki-Ho
    • Journal of the Korean Data and Information Science Society
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    • v.22 no.3
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    • pp.401-412
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    • 2011
  • This study uses a vector error correction model to analyze the daily time series data of the spot price of EUA (European Union Allowance). As endogenous variables, five variables are considered for the analysis, including prices of crude oil, natural gas, electricity and coal in addition to carbon price. Data period is Phase 2 period (April 21, 2008 to March 31, 2010) to avoid Phase 1 period (2005-2007) where the EUA prices were distorted. Unit-root and cointegration test results reveal that all variables have a unit root and cointegration vectors exist, so a vector error correction model is adopted instead of a vector autoregressive model.