• 제목/요약/키워드: Fluidity Index

검색결과 21건 처리시간 0.036초

광물질 혼화재 치환이 고유동 콘크리트의 재료분리 저항성에 미치는 영향 (Influence of High Fluidity Concrete on Segregation Resistance When Replacing Mineral Admixture)

  • 이혁주;이영준;현승용;한인덕;한동엽;한민철
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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    • pp.139-140
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    • 2019
  • In this study, we considered the influence on segregation resistance at the time of substitution of FA and BS, which are substance admixtures of high fluidity concrete. According to the research results, EIS, which is an index of segregation in high fluidity concrete replacement, showed a low value, and the composition also showed a higher value than OPC. Therefore, it is confirmed that the resistance to segregation at the time of admixture replacement of high fluidity concrete is improved.

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A Study on Financial Ratio and Prediction of Financial Distress in Financial Markets

  • Lee, Bo-Hyung;Lee, Sang-Ho
    • 유통과학연구
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    • 제16권11호
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    • pp.21-27
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    • 2018
  • Purpose - This study investigates the financial ratio of savings banks and the effect of the ratio having influence upon bankruptcy by quantitative empirical analysis of forecast model to give material of better management and objective evidence of management strategy and way of advancement and risk control. Research design, data, and methodology - The author added two growth indexes, three fluidity indexes, five profitability indexes, and four activity indexes CAMEL rating to not only the balance sheets but also the income statement of thirty savings banks that suspended business from 2011 to 2015 and collected fourteen financial ratio indexes. IBMSPSS VER. 21.0 was used. Results - Variables having influence upon bankruptcy forecast models included total asset increase ratio and operating income increase ratio of growth index and sales to account receivable ratio, and tangible equity ratio and liquidity ratio of liquidity ratio. The study selected total asset operating ratio, and earning and expenditure ratio from profitability index, and receivable turnover ratio of activity index. Conclusions - Financial supervising system should be improved and financial consumers should be protected to develop saving bank and to control risk, and information on financial companies should be strengthened.

고강도 분체계 고유동 콘크리트의 J-Ring을 이용한 재료분리 판정 분석 (Segregation Evaluation Method using J-Ring of High Strength High Fluidity Concrete)

  • 이혁주;이영준;현승용;한동엽;한인덕;한민철
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2018년도 추계 학술논문 발표대회
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    • pp.157-158
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    • 2018
  • In this study, the current tendency to replace a large amount of material admixture, which is fly ash (FA) and blast furnace slag (BS), into concrete is that high-grade cheese high admixture of high fluidity concrete In consideration of the substitution rate, we considered J-Ring to investigate the influence on the segregation resistance and the method of evaluating the classical segregation. In addition to the admixture replacement rate in the study results, the EIS using J-Ring became lower and the percentage of vehicles with segregation increased. Such a tendency is considered to be positive when J-Ring is used when segregation is judged if segregation degree is similar to EIS using J-Ring.

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분체계 고유동 콘크리트의 재료분리 판정방법 분석 (Segregation Evaluation Method for Powder Based High Fluidity Concrete)

  • 이혁주;한준희;이재진;한동엽;한인덕;한민철
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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    • pp.140-141
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    • 2018
  • There are three types of high fluidity concrete: powder based, VMA based, and combined. In the case of the powder based high fluidity concrete mixture, according to the textbook, increased viscosity due to the replaced fly ash can prevent segregation of coarse aggregate. On the other hand, decreased density of the powder due to the fly ash replacement can causes segregation but there is no report on this issue. Therefore, in this research, the segregation resistance and segregation evaluation method for powder based high fluid concrete mixture are evaluated. As a result, with increased replacing ration of supplementary materials, EIS value was decreased and apparently segregation resistance was increased. However, from the compressive strength evaluation depending on height of the cylindrical specimen, it was confirmed that the different of strength difference between top and bottom part of the specimen. Thus, following research regarding vertical segregation should be studied.

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수분 안정성 향상을 위한 천마 추출물 함유 분말의 제조 및 평가 (Fabrication and Characterization of Gastrodia elata-loaded Particles for Increased Moisture Stability)

  • 정재환;진성규
    • 한국분말재료학회지
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    • 제27권3호
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    • pp.241-246
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    • 2020
  • To develop Gastrodia elata (GE)-loaded particles for herbal extract dosage forms, various GE-loaded particles containing dextrin, isomalt, maltodextrin, and silicon dioxide as solidifying carriers in the GE water extract are prepared using the spray drying method. Their physical properties are evaluated using the repose angle, Hausner ratio, Carr's index, weight increase rate at 40℃/75% RH condition, and scanning electron microscopy (SEM). Particles made of dextrin improve the fluidity, compressibility, and water stability. In addition, 2% silicon dioxide increases the fluidity and moisture stability. The best flowability and compressibility of GE-loaded particles are observed with TP, dextrin, and silicon dioxide amounts in the ratio of 6/4/0.2 (34.29 ± 2.86°, 1.48 ± 0.03, and 38.29 ± 2.39%, repose angle, Hausner Ratio, and Carr's index, respectively) and moisture stability with a 2% weight increase rate for 14 h at 40℃/75% RH condition. Therefore, our results suggest that the particles prepared by the spray drying method with dextrin and 2% silicon dioxide can be used as powerful particles to improve the flowability, compressibility, and moisture stability of GE.

안료 함량에 따른 잉크의 레올로지 성질의 변화 (Rheological Properties According to the Pigment Concentration of Ink)

  • 박정민;김성빈;조진우
    • 한국인쇄학회지
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    • 제21권1호
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    • pp.71-80
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    • 2003
  • Printing inks are mainly composed of pigment and vehicles. Among these components, the Vehicle affect the rheologic property of the ink the most but pigment content or characteristic also affect to the fluidity property not less than the vehicle. In the study, with the same vehicle on each sample, by making the sample to increase pigment content gradually. It can be examined the influence of the pigment to the fluidity of ink. In result we found that the viscosity value of the low shear rate rang has relatively higher value with increasing the pigment content in the ink. According to higher pigment content, yield stress and thixotropy index increases gradually. Structure recovery of the ink is that, the higher pigment content's ink, the less changing shear rate, and it takes less time to recover.

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trans 지방산 함유 지방이 콜레스테롤대사와 간 세포막 유동성에 미치는 영향 (Effect of trans Fatty acid containing Fats on Cholesterol Metabolism and Hepatic Membrane Fluidity in Rats)

  • 김찬희;원미숙;송영선
    • 생명과학회지
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    • 제12권6호
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    • pp.769-779
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    • 2002
  • 식생활의 변화로 인해 fast food 및 가공식품의 소비가 급속히 증가하고 있으며 이러한 식품에 많이 함유되어 있는 trans 지방산의 생리적 기능에 대한 관심이 모아지고 있다. 따라서 본 연구에서는 한국인이 즐겨 섭취하는 유지중 trans 지방산 함량을 함유하고 있는 마가린, 버터의 장기간 섭취가 횐쥐의 콜레스테롤 대사와 세포막 유동성에 미치는 영향을 옥수수유와 비교하여 trans 지방산 함유 식품의 생리기능성을 제시하고자 하였다. 이유 직후의 흰쥐(S.D. male)를 trans 지방산 함량이 다른 마가린(25%)과 버터(8.5%), 옥수수유를 포함하는 식이로 각각 8주간 섭취시켜 사육한 결과, 체중증가와 1일 식이 섭취량은 식이군간에 차이가 없었으나 trans 지방산을 함유한 식이군(마가린, 버터)의 식이효율이 감소하였다. 혈장 지질 조성에서 중성지방 농도는 차이가 없었지만, 콜레스테롤 농도는 옥수수유 식이군에 비해 trans 지방산을 함유한 식이군에서 유의적으로 낮았다. 지단백 획분 중 LDL 콜레스테롤 농도는 옥수수유 식이군에 비해 마가린 식이군에서 유의적으로 낮았으며, 버터 식이군에서 유의적으로 높았다. HDL 콜레스테롤 농도는 버터 식이군이 다른 식이군에 비해 낮았으며 그 결과 버터 식이군의 동맥경화지수가 가장 높았다. 또한 간 중성지방 함량은 마가린과 옥수수유 식이군에 비해 버터 식이군에서 낮았으며 콜레스테롤의 농도는 옥수수유 식이군에서 가장 높았다. 간 조직으로의 trans 지방산의 축적 정도는 마가린 식이군에서 가장 높았으며 간의 HMG-CoA reductase 활성은 버터와 마가린 식이군에서 다소 감소하였다. 분변으로의 콜레스테롤 배설량은 trans 지방산을 함유한 마가린과 버터 식이군에서 유의적으로 높았으며 배설되는 trans 지방산 함량은 마가린 식이군에서 가장 높았다. 세포막 유동성은 옥수수유군에 비해 마가린과 버터식이군에서 유의적으로 감소하였다. 본 연구의 결과로 미루어 볼 때 trans 지방산 함유 지방 섭취에 의한 고콜레스테롤혈증 유발효과는 확인할 수 없었으며, trans 지방산의 섭취가 분변으로의 콜레스테롤 배설을 증가시키고 HMG-CoA reductase 활성을 저하시켜 혈장 콜레스테롤을 감소시킨 것으로 사료되며 버터군에서 동맥경화지수가 가장 높게 나타난 것은 버터의 포화지방산, 특히 미리스틴산과 팔미트산의 높은 함량 때문으로 사료된다. 그러나 마가린과 버터식이군의 세포막 유동성이 현저히 감소한 것은 세포막에서 trans 지방산이 포화지방산과 유사한 거동을 보이는 때문으로 풀이된다.

만성퇴행성 질환에 미치는 다시마(Laminaria japonica)와 후코이단 성분의 영향 (Effects of Sea Tangle (Laminaria japonica) and Fucoidan Components on Chronic Degenerative Diseases)

  • 최진호;김대익;박수현;김동우;이종수;유종현;정유섭
    • 생명과학회지
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    • 제9권4호
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    • pp.430-438
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    • 1999
  • This study was designed to investigate the effects of sea tangle (Laminaria japonica) extract and fucoidan components on chronic degenerative diseases. Sprague-Dawley(SD) male rats (210$\pm$5g) were fed experimental diets: Dasi-Ex group: dasima extract powder of 4.0% added to control diet; Fuco-I, II and III groups: fucoidan powder of 1, 2 and 3% added to Dasi-Ex group for 45 days. Triglyceride (TG) levels in serum were significantly lower (10~15%) in Fuco-I, II and III groups compared with control group. Total cholesterol levels were significantly decreased (7~10% and 15~ 35%) in brain mitochondria and microsomes of Fuco-II and III group compared with control group. LDL-cholesterol levels were remarkably decreased (20~30%) in Dasi-Ex and Fuco-I, II, III groups, but HDL-cholesterol levels were significantly increased (10~12%) in Fuco-II and III groups only compared with control group. The ratios of HDL/total cholesterol resulted in a marked increase (3 5~55%) in Dasi-Ex and Fuco-I, II, III groups, but atherogenic indices were remakably decreased (40~50%) in Dasi-Ex and Fuco-I, II, III groups compared with control group. Membrane fluidities were remarkably increased (45~70% and 38~42%, respectively) in brain mitochondria and microsomes of Fuco-II and III groups compared with control group. Administrations of fucoidan added to dasima effectively decreased TG, total and LDL-cholesterol, and atherogenic index, while also effectively increased HDL-cholesterol, HDL/total cholesterol ratio, and membrane fluidity, suggesting chronic degenerative diseases were very effectively prevented by the administration of fucoidan component.

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물 결합재 비에 따른 알칼리 활성 슬래그 페이스트의 레올로지 특성에 관한 실험적 연구 (Experimental Study on Rheological Properties of Alkali Activated Slag Pastes with Water to Binder Ratio)

  • 김병조;송진규;송금일;오명현;이방연
    • 콘크리트학회논문집
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    • 제27권5호
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    • pp.511-519
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    • 2015
  • 콘크리트의 유동성을 평가하기 위해서는 주로 테이블 플로우, 슬럼프 및 유하시간 측정 등의 방법이 이용된다. 하지만 이러한 방법은 시험 조건이 바뀌면 정확한 비교분석이 어렵기 때문에 정량적 변수로 표현되는 레올로지를 이용하여 콘크리트의 유동성을 평가하는 연구가 증가하고 있다. 한편, 시장의 요구에 따라 AAS 결합재에 대한 수요는 증가하고 있으나, AAS 결합재의 레올로지에 대한 연구는 전무한 실정이다. 따라서 이 논문에서는 물/결합재 비와 알칼리 활성화제 유형에 따른 AAS 페이스트의 레올로지 특성을 분석하고자 한다. 테이블 플로우와 유하시간을 측정하여 AAS 페이스트의 유동성을 평가하였고, 레올로지 시험을 통해 전단속도에 따른 전단응력을 분석하였다. 레올로지 시험결과를 Bingham model로 가정하여 레올로지 정수를 도출하고 유동성 평가 시험과의 상관관계를 분석하였다. 결과적으로, 테이블 플로우와 항복응력, 유하시간과 소성점도와의 관계식을 제시하였다. 연구결과를 기반으로, AAS 모르타르 및 콘크리트를 제작하는데 참고자료로 제시하고자 한다.

설계강도 $40N/mm^2$ 매스콘크리트인 전이층보의 수화열 해석을 통한 온도 균열 제어에 관한 연구 (A Study on the Temperature Crack Control for Analysis of Hydration Heat of Mass Concrete Transfer Girder with Design Strength $40N/mm^2$)

  • 이종석;김주상;강연우;김재환;이상수;송하영
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2007년도 춘계학술논문 발표대회
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    • pp.33-36
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    • 2007
  • In order to select the optimum mix for the required fluidity and strength of mass concrete which is applied to transfer girder and to choose the optimum curing method depending on circumstances through hydration heat analysis of mass concrete, this study examined slump flow, air content and elapsed variation (0, 30, 60, 90) in unhardened concrete properties and reviewed compressive strength characteristics in hardening properties. And hydration heat analysis results through simulation are as follows; 1) Fluidity changes of unhardened concrete showed no significant difference, and those of elapsed variation also showed no difference but a bit of tendency to increase in comparison with the initial properties. 2) The higher the water-binder ratio was, the lower the compressive strength properties were, and the higher the fly ash replacement rate was, the lower the compressive strength development was. 3) In case of $Fc=40N/mm^2$, the optimum mix was fly ash replacement rate of 15% from water-binder ratio of 33.0%. 4) Hydration heat analysis results showed that in case of bundle cast, concrete temperature profile characteristics around transfer girder was unfavorable, and in case of separate cast, constant curing for at least seven days guaranteed thermal cracking index of 1.2.

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