• 제목/요약/키워드: Capillary method

검색결과 507건 처리시간 0.025초

식물성 유지 및 폐식용유를 사용한 고강도 콘크리트의 자기수축 및 공학적 특성 (Autogenous Shrinkage and Engineering Properties of the High Strength Concrete Using Soybean and Waste Edible Oil)

  • 한민철;이동규
    • 한국건설순환자원학회논문집
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    • 제6권3호
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    • pp.110-117
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    • 2011
  • 본 연구에서는 콩기름과 자원 재활용 차원의 폐식용유의 새로운 자기수축 저감방안으로서의 가능성을 검토하고자 수축저감제 및 팽창재와 비교 분석하였는데, 그 결과는 다음과 같다. SO 및 WO는 Plain에 비해 유동성이 소폭 저하되었으나 공기량에서는 큰 차이를 보이지 않았고, 강도결과는 재령 28일에 유지류에서 약간의 저하가 발생하였지만 대부분의 수준에서 양호한 결과를 나타냈다. 자기수축 저감효과는 SO와 WO가 RS 및 EA보다 우수함을 확인할 수 있었는데, 이는 SO과 WO의 지방산이 시멘트 수화물 중 $Ca(OH)_2$와 가수분해 반응을 진행하여 지방산 칼슘염을 생성하게 되는데, 이러한 생성물들이 콘크리트 경화체내의 모세관 공극을 충전시켜 수축완화 작용에 기인한 것으로 사료된다. 공극분포 측정결과 SO 및 WO의 경우 치환율에 상관없이 $0.01{\sim}0.1{\mu}m$ 사이즈의 공극이 0 ml/g으로 나타났으며, $10{\sim}100{\mu}m$ 사이즈의 공극이 매우 적은 것으로 나타나 유지류가 콘크리트의 미세공극을 충전해주는 역할을 하는 것으로 판단된다.

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두충차와 감잎차의 향기성분 (The Aroma Components of Duchung Tea and Persimmon Leaf Tea)

  • 최성희
    • 한국식품과학회지
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    • 제22권4호
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    • pp.405-410
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    • 1990
  • 국산 대용차 중 시판되고 있는 두충차와 감잎차의 향기성분을 연속증류 추출법으로 추출하여 GC-MS에 의하여 분석, 동정하였다. 두충차에서는 hydrocarbon류 3종, alcohol류 17종, ketone류 15종, aldehyde류 16종, acid류 8종, hetero 고리화합물류 8종과 phenol류 2종을 포함한 총 77종류의 향기성분을 확인하였다. 두충차에 많이 존재하는 ketone류(14.59%) aldehyde류(23.31%)와 hetero 고리화합물(16.71%)들은 두충차의 특징인 달콤하고 한약재에 가까운 향기에 기여한다고 생각된다. 감잎차에서는 hydrocarbon류 10종, alcohol류 17종, ketone류 11종, aldehyde류 13종, ester류 8종, acid류 6종, hetero 고리화합물 5종과 phenol류 1종을 포함한 총 71종을 확인 하였다. 감잎차에는 향기의 기여도가 낮은 hydrocarbon류의 함량(10.40%)이 두충차에 비해 많았고 alcohol류의 함량(25.57%)이 현저하게 많아 은은하고 순한 감잎차의 특유향에 기여한다고 생각된다.

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형광염색을 이용한 혈관내봉한관의 관찰 (Fluorescent Method for Observing Intravascular Bonghan Duct)

  • 이병천;백구연;정현민;성백경;소경순;강대인;소광섭
    • 대한약침학회지
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    • 제8권3호
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    • pp.5-9
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    • 2005
  • 미분간섭현미경법과 아크리딘-오렌지(acridine-orange) 형광 염색을 이용하여 쥐 혈관 내의 실 모양 구조물을 관찰하였다. 공초점현미경법과 헤마톡실린-에오신(hematoxylin-eosin) 염색을 통해 피브린, 모세혈관, 소정맥, 소동맥 혹은 림프관의 핵 분포와 뚜렷이 구별되는 혈관 내 실 모양 구조물의 핵 분포 패턴을 얻어낼 수 있었다. 이 실 모양 구조물의 생리적 기능을 침술과 연관하여 논의하였다. 특히, 이 실 모양 관을 통한 약물의 흐름이 약침의 기전에 해당할 것이라는 가설을 제기하였다.

미병 정량 지표에 관한 중국의 임상연구 동향 분석 - China National Knowledge Infrastructure를 중심으로 - (Analysis of Clinical Research Trends on Quantitative Indicators of Mibyeong in China - Using China National Knowledge Infrastructure -)

  • 여민경;이영섭
    • 대한예방한의학회지
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    • 제22권1호
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    • pp.15-28
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    • 2018
  • Objectives : The purpose of this study was to analyze the trend of clinical research on quantitative indicators of Mibyeong in traditional chinese medicine(TCM). Method : The journal search was performed using china national knowledge infrastructure(CNKI) database. Our inclusion criteria were as following: TCM clinical researches for quantitative indicators of Mibyeong. Exclusion criteria were as following: non-TCM clinical researches, used intervention methods. Results : Eleven clinical researches were analyzed in this study. Four of these researches classify the Mibyeong as a type of pattern identification(PI) and studied the characteristics of the PI quantitative indicators. Mibyeong diagnosis was done through guidelines and questionnaires, each was used at a similar rate. Quantitative indicators mentioned in the selected researches were blood indices, nailfold capillary, complexion, color of tongue substance and coating, pulse wave diagrams and heart rate variability. Among them, seven researches related to blood indices were the most. Blood indicators include whole-blood viscosity, plasma viscosity, fibrinogen, packed cell volume(Hct), triglycerides, total cholesterol, HDL-C, LDL-C, glucose, BUN/CREA, luteinzing hormone, estradiol, follicle stimulating hormone, IgA, IgG, etc. Conclusions : Based on this results, in combination with western medicine, it seems necessary to try to interpret the Mibyeong in more various ways. Even if the same Mibyeong, it is necessary to identify the index which changes according to the PI or chief complaint, and to set the Mibyeong standard corresponding thereto.

Effects of Relative Humidity and Temperature on the Transport of Chloride in the Concrete

  • Nam Jin-Gak;Hartt William H.;Kim Ki-Joon
    • 콘크리트학회논문집
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    • 제17권5호
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    • pp.821-828
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    • 2005
  • To investigate the role of RH and temperature on the transport of chloride in the concrete, two groups of specimens were configured. For both groups, mix design was based on w/c=0.45, $400kg/m^3$ cement, $794kg/m^3$ fine aggregate and $858kg/m^3$ coarse aggregate. After specimen fabrication these were exposed to four different RH (35, 55, 75 and $95\%$ RH) and temperature (0, 20, 30 and $40^{\circ}C$) conditions. After 3 and 6 months $15\%$ NaCl exposure 5mm cores were taken. These cores were sliced and individual cores were ground to powder. In addition, to evaluate the effect of temperature on the chloride binding some powder samples were leached in the each of four temperature chambers. Chloride titration fur these was performed using FDOT acid titration method. Based upon the resultant data conclusions were reached regarding that 1) effective diffusion coefficient, $D_e$, increased with increasing exposure RH, suggesting that the size and number of water paths increased with elevated moisture content in the specimens, 2) $D_e$ increased with increasing temperature in the range of 0 to $40^{\circ}C$ possibly by elevated thermal activation of chloride ions and reduced chloride binding at higher temperature, 3) water soluble chloride concentration, $[Cl^-]_s$, increased with increasing temperature, and 4) chloride concentration profile for initially dry concrete specimens was higher than for the initially wet ones indicating pronounced capillary suction (sorption) occurred for the dry concrete specimens.

조류생산잠재력조사 방법개발에 의한 육수환경의 부영양화 방지대책에 관한 연구(I) -순수분리종의 형태 및 증식특성- (A Study on Protection Plan of Eutrophication in Fresh Water Environment by Development of Methods for Algal Growth Potential test (I) -Morphology and Growth Characteristics of Isolated algae-)

  • 위인선;나철호;이종빈;주현수
    • 한국환경보건학회지
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    • 제23권1호
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    • pp.18-27
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    • 1997
  • The isolation, morphological study and growth characteristics of the algae were investigated from Lake Chuam. The isolated algae were applied the Agal Growth Potential test. The method of isolation and purification of the algae were used to Agar plating(AP), nutrient enrichment(NE), dilution(DI) and micro capillary technique(MC). Total isolated algae were 21 species. They were composed of Cyanophyceae, Dinophyceae, Bacillariophyceae, Euglenophyceae and Chlorophyceae. The numbers of algal strain by isolation technique were highest in dilution(21 species), and those of the rests were showed in order of NE > MC > AP. The sizes of isolated Selenastrum and Scenedesmus were $1.8\pm 1.4 \mu m$, $3.3\pm 0.9 \mu m$ in diameter and $6.4\pm 2.3 \mu m$, $13.6\pm 1.9 \mu m$ in length respectively. The morphology of isolated algae and NIES-collection strain was very similar each other, but the size was smaller isolated algae than that of NIES-collection. The optimum culture condition of isolated Selenastrum and Scenedesmus was about 30$\circ$C(25$\circ$C-35$\circ$C) in temperature and the maximum growth was appeared between 7,000 lux and 8,000 lux in the light intensity. The comparison of $\mu$(specific growth rate) on the concentration of nutrients such as nitrate and phosphate, isolated Selenastrum was appeared maximum it at 1.0 mg $NO_3-N/l$ but NIES-collection strain was showed 95% of maximum it at same nitrate concentration. Maximum g of isolated algae and NIES-collection strain in Scenedesmus onto nitrate concentration were very similar with the result of selenastrum. The specific growth rates of isolated algae and NIES-collection strain on the gradient concentration of phosphate were showed 0.72/day and 0.70/day at 0.02 mg $PO_4-P/l$ in Selenastrum but those of Scenedesmus were appeared 0.61/day and 0.57/day at same concentration $PO_4-P$.

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2차원 기공층을 포함하는 초박형 단열기판의 미세구조 및 단열 특성 (Microstructure and Thermal Insulation Properties of Ultra-Thin Thermal Insulating Substrate Containing 2-D Porous Layer)

  • 유창민;이창현;신효순;여동훈;김성훈
    • 한국전기전자재료학회논문지
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    • 제30권11호
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    • pp.683-687
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    • 2017
  • We investigated the structure of an ultra-thin insulating board with low thermal conductivity along z-axis, which was based on the idea of void layers created during the glass infiltration process for the zero-shrinkage low-temperature co-fired ceramic (LTCC) technology. An alumina and four glass powders were chosen and prepared as green sheets by the tape casting method. After comparison of the four glass powders, bismuth glass was selected for the experiment. Since there is no notable reactivity between alumina and bismuth glass, alumina was selected as the supporting additive in glass layers. With 2.5 vol% of alumina powder, glass green sheets were prepared and stacked alternately with alumina green sheet to form the 'alumina/glass (including alumina additive)/alumina' structure. The stacked green sheets were sintered into an insulating substrate. Scanning electron microscopy revealed that the additive alumina formed supporting bridges in void layers. The depth and number of the stacking layers were varied to examine the insulating property. The lowest thermal conductivity obtained was 0.23 W/mK with a $500-{\mu}m-thick$ substrate.

소아 연령군에서의 냉각-산소화-희석-혈심정지액을 이용한 심근 보호에 대한 임상적 고찰 (Clinical Trial of Myocardial Protection using Cold Oxygenated Diluted Blood Cardioplegia in Child Age)

  • 이정렬;김용진
    • Journal of Chest Surgery
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    • 제25권3호
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    • pp.211-219
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    • 1992
  • Hypothermic cardioplegia is a well established method to optimize myocardial preservation during ischemic arrest, and it has been demonstrated that oxygenation of crystalloid cardioplegic solutions markedly enhances myocardial protection, The addition of a small amount of red blood cells to a crystalloid cardioplegic solutions improves capillary perfusion. Considering these results, we changed our cardioplegic solution from cold oxygenated crystalloid[Group 2] to cold oxygenated diluted blood[Group 1]. In this investigation, we examined the effects of two hypothermic potassium cardioplegic solutions on myocardial preservation in 50 patients[30 of Group 1 and 20 of Group 2] of child age group. Factors considered preoperatively included age, sex, body weight, preoperative diagnosis, and they showed no statistical differences, Intraoperative factors considered included duration of cardiopulmonary bypass, duration of aortic occlusion, operative mortality, which also revealed no statistically significant differences, We measured the serum levels of GOT[glutamate oxaloacetate transaminase] and CPK [creatine phosphokinase] during the first two days postoperatively, which, in both groups, showed significantly higher values until postoperative 1 day, and decreasing tendancy thereafter, however we failed to find any significant difference between two groups regarding the serum levels of those enzymes each day. Time for extubation and use of inotropics also revealed no significant differences. Defibrillation was needed less in Group 1 than in Group 2[p<0.05], and one case of supraventricular tachyarrhythmia occured in Group l. We conclude that cold oxygenated diluted blood cardioplegia provides no less preservation than does an oxygenated crystalloid cardioplegic solution in child age group.

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소결 온도와 유지 시간에 따른 Fe-Cr-Al 다공성 금속의 제조 (Fabrication of Fe-Cr-Al Porous Metal with Sintering Temperature and Times)

  • 구본욱;이수인;박다희;윤중열;김병기
    • 한국분말재료학회지
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    • 제22권2호
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    • pp.100-104
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    • 2015
  • The porous metals are known as relatively excellent characteristic such as large surface area, light, lower heat capacity, high toughness and permeability. The Fe-Cr-Al alloys have high corrosion resistance, heat resistance and chemical stability for high temperature applications. And then many researches are developed the Fe-Cr-Al porous metals for exhaust gas filter, hydrogen reformer catalyst support and chemical filter. In this study, the Fe-Cr-Al porous metals are developed with Fe-22Cr-6Al(wt) powder using powder compaction method. The mean size of Fe-22Cr-6Al(wt) powders is about $42.69{\mu}m$. In order to control pore size and porosity, Fe-Cr-Al powders are sintered at $1200{\sim}1450^{\circ}C$ and different sintering maintenance as 1~4 hours. The powders are pressed on disk shapes of 3 mm thickness using uniaxial press machine and sintered in high vacuum condition. The pore properties are evaluated using capillary flow porometer. As sintering temperature increased, relative density is increased from 73% to 96% and porosity, pore size are decreased from 27 to 3.3%, from 3.1 to $1.8{\mu}m$ respectively. When the sintering time is increased, the relative density is also increased from 76.5% to 84.7% and porosity, pore size are decreased from 23.5% to 15.3%, from 2.7 to $2.08{\mu}m$ respectively.

종이-미세유체공학을 이용한 건성안 검사 용지 개발 (Development of Paper-based Microfluidic Device for Dry Eye Test)

  • 서영태;노혜란
    • 한국안광학회지
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    • 제18권2호
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    • pp.93-99
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    • 2013
  • 목적: 본 연구는 현장현시 건성안 진단 테스트 중에 현재 사용되고 있으나 부정확한 결과로 신뢰도가 떨어지는 쉬르머 용지를 대체 할 수 있는 차세대 건성안 진단 테스트 용지를 미세유체공학을 이용하여 개발하고자 하였다. 방법: 왁스로 패턴을 제조한 친수성 크로마토그래피 용지를 pH에 따른 색 변화가 나타나도록 안토시안으로 염색을 하였다. 인공 누액의 젖음 속도를 인공 누액과 32명의 참가자의 눈물을 이용하여 임상 측정하였다. 결과: 인공 누액을 이용하였을 경우 쉬르머 용지에서는 소량의 용액은(0.5 ml이하) 흡수거리가 도출되지 않았으나 새로 개발된 용지는 시간에 따른 인공 누액의 흡수거리가 확연히 나타났다. 임상실험에서도 새로 개발된 검사 용지는 TBUT (tear break-up time)결과와 부합하는 건성안 진단 결과를 보였다. 결론: 개발된 건성안 진단 용지는 간편하게 사용될 수 있을 뿐만 아니라 기존 쉬르머 용지와 같은 현장현시 건성안 진단 매체와 비교 했을 경우 건성안 판별의 정확성이 높았다.