• Title/Summary/Keyword: Curing Time

검색결과 1,195건 처리시간 0.028초

이대간(易大艮)의 붕루(崩漏) 의안(醫案)과 유창의 진한가열(眞寒假熱) 의안(醫案)에 관한 문헌적(文獻的) 연구(硏究) (A Study of the Medical Records on Metrostaxis(崩漏) of that Made a Profound Study by Yi-Da-Gan(易大艮) and Cold Syndrome with Pesudo-Heat(眞寒假熱) of that Made a Profound Study by Yu-Chang(喩昌))

  • 김태희;한경숙;박영배
    • 대한한의진단학회지
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    • 제9권2호
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    • pp.1-9
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    • 2005
  • Background: Liu-Yuan-Lei(陸淵雷) said that a medical record is both the marks of treatments and arts made by a excellent practitioner and the essence of TCM(Traditional Chinese Medicine). Jiang-Guan(江瓘) also said that reading medical records is one of the best way to develop one’s abilities If curing a disease without perfect clinical practice. Objectives: study on the special treatment about metrostaxis(崩漏) based on the Yi-Da-Gan(易大艮)’s medical records. and study on the differentiation of abnormal symptoms and signs about cold syndrome with pesudo-heat(眞寒假熱) based on the Yu-Chang(喩昌)'s medical records. Methods: First, read and study the medical records on metrostaxis(崩漏) of that made a profound study by Yi-Da-Gan(易大艮) and cold syndrome with pesudo-heat(眞寒假熱) of that made a profound study by Yu-Chang(喩昌). The next, write a paper on results and conclusions. Results and Conclusions: First, Yi-Da-Gan(易大艮) insist that must control the Qi under the blood disease conditions, taking the case of metrostaxis(崩漏). Secondly, we must study more on estimating the changing condition of Qi and the blood as time goes by, also study on the pulse and pulse condition in the four seasons(四時脈). Thirdly, Yu-Chang(喩昌) insist that be more careful in differentiation of symptoms and signs, taking the case of cold syndrome with pesudo-heat(眞寒假熱). Fourthly, Yu-Chang(喩昌) give an example that in condition of cold syndrome with pesudo-heat(眞寒假熱), sometimes, the pulse and pulse condition can be strong.

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LCD 램프홀더용 실리콘고무재료의 후가교 조건 (Post-cure Condition of a Silicone Rubber Material for a LCD Lamp Holder)

  • 안원술;이준만
    • 한국산학기술학회논문지
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    • 제10권7호
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    • pp.1661-1667
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    • 2009
  • TGA 열분석법을 이용하여 LCD 백라이트 램프 홀더용으로 사용되는 실리콘 고무성형품샘플에 대하여 서로 다른 몇 가지 온도에서의 등온 후가교 특성을 연구하였다. 특히 실제 사용 환경에서의 내열조건과 관련된 후가교 특성 및 적정 후가교 조건에 대하여 촛점을 맞추어 연구하였고 시간-온도중첩원리를 응용하는 촉진 실험법의 적용 가능성을 알아보았다. LCD 램프홀더용의 실리콘 재료의 실제 사용 환경을 고려할 때, 휘발성 물질의 배출에 의한 중량감소가 처음 시작되는 온도인 Ti가 가장 중요한 고려 요인이며, 이를 고려하여 도출되는 후가교 조건은 $250^{\circ}C$, 2시간이 적절한 것으로 생각되었다. 시간-온도 중첩원리와 실험적으로 결정된 이동인자는 Arrhenius식을 잘 만족함을 보여 주었으며 이로부터 후가교과정은 활성화에너지 108.25kJ/mol의 값을 가지는 단일 메커니즘으로 진행됨을 알 수 있었다.

장경간 강바닥판 케이블교량에 적용하기 위한 폴리우레탄 폴리머콘크리트의 공용특성 연구 (A Study to Evaluate Performance of Poly-Urethane Polymer Concrete for Long-Span Orthotropic Steel Bridge)

  • 박희영;이정훈;곽병석;최이현;김태우
    • 한국도로학회논문집
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    • 제15권1호
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    • pp.1-9
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    • 2013
  • PURPOSES: The purpose of this study is to evaluate physical properties, durability, fatigue resistance, and long-term performance of poly-urethane concrete (PU) which can be possible application of thin layer on long-span orthotropic steel bridge and to check structural stability of bridge structure. METHODS : Various tests of physical properties, such as flexural strength, tensile strength, bond strength and coefficient of thermal expansion tests were conducted for physical property evaluation using two types of poly urethane concrete which have different curing time. Freezing and thawing test, accelerated weathering test and chloride ion penetration test were performed to evaluate the effect of exposed to marine environment. Beam fatigue test and small scale accelerated pavement test were performed to assess the resistance of PU against fatigue damage and long-term performance. Structural analysis were conducted to figure out structural stability of bridge structure and thin bridge deck pavement system. RESULTS: The property tests results showed that similar results were observed overall however the flexural strength of PUa was higher than those of PUb. It was also found that PU materials showed durability at marine environment. Beam fatigue test results showed that the resistances of the PUa against fatigue damage were two times higher than those of the PUb. It was found form small scale accelerated pavement test to evaluate long-term performance that there is no distress observed after 800,000 load applications. Structural analysis to figure out structural stability of bridge structure and thin bridge deck pavement system indicated that bridge structures were needed to increase thickness of steel deck plate or to improve longitudinal rib shape. CONCLUSIONS: It has been known that the use of PU can be positively considered to thin layer on long-span orthotropic steel bridge in terms of properties considered marine environment, resistance of fatigue damage and long-term performance.

포장용 콘크리트의 강도 및 탄성계수 상관관계식 (Strength and Modulus Relationship of Concrete for Rigid Pavement)

  • 양성철;박종원
    • 한국도로학회논문집
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    • 제9권4호
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    • pp.205-213
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    • 2007
  • 본 연구에서는 포장용 콘크리트의 강도실험을 통해 강도간의 상관관계식을 도출하는 것을 목적으로 하였다. 강도로서 재령별 압축강도, 휨강도, 할렬인장강도와 탄성계수를 측정하였다. 배합변수는 조골재(화강암, 석회암, 사암), 세골재(자연사, 세척사, 부순모래) 및 단위시멘트량(315-375kg)을 변수로 하였다. 전체적으로 골재나 단위시멘트량보다는 재령에 의해 전형적인 강도곡선을 따라 뚜렷하게 변화함을 보여준다. 이러한 강도결과를 바탕으로 휨강도와 압축강도, 할렬인장강도와 압축강도, 탄성계수와 압축강도, 할렬인장강도와 휨강도의 상관관계를 분석한 결과 휨강도와 압축강도, 탄성계수와 압축강도는 기존의 관례대로 제곱근(n=0.5)의 상관관계식이 잘 맞음을 알 수 있었다. 할렬인장강도와 휨강도는 선형의 상관관계식으로 표현하였고, 할렬인장강도와 압축강도는 n=0.87의 지수승을 사용한 경우가 가장 적합한 것으로 나타났다.

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Anxiolytic-Like Effects of Chrysanthemum indicum Aqueous Extract in Mice: Possible Involvement of GABAA Receptors and 5-HT1A Receptors

  • Hong, Sa-Ik;Kwon, Seung-Hwan;Kim, Min-Jung;Ma, Shi-Xun;Kwon, Je-Won;Choi, Seung-Min;Choi, Soo-Im;Kim, Sun-Yeou;Lee, Seok-Yong;Jang, Choon-Gon
    • Biomolecules & Therapeutics
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    • 제20권4호
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    • pp.413-417
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    • 2012
  • Chrysanthemum indicum Linne is an ancient herbal medicine used to treat bone and muscle deterioration, ocular inflammation, headache, and anxiety in Korea, China, and Japan. Furthermore, tea derived from Chrysanthemum indicum Linne has been used to treat anxiety by facilitating relaxation and curing insomnia. However, no reports exist on the anxiolytic-like effects of Chrysanthemum indicum Linne water extract (CWE) in mice. In the present study, we investigated the anxiolytic-like effects of CWE using the elevated plus-maze (EPM) test in mice. CWE, at a dose of 500 mg/kg (p.o.), significantly increased the time spent in the open arms of the EPM compared to a vehicle-injected control group. Moreover, the effect of CWE (500 mg/kg) was blocked by bicuculline (a selective $GABA_A$ receptor antagonist) and WAY 100635 (a selective 5-$HT_{1A}$ receptor antagonist). Taken together, these findings suggest that the anxiolytic-like effects of CWE might be mediated by the $GABA_A$ receptor and the 5-$HT_{1A}$ receptor.

순결형 그라우트의 초기 전단강도 특성에 대한 연구 (A Study on the Initial Shear Strength Characteristics of Sudden Gelation Grout)

  • 허형석;박인준
    • 한국지반공학회논문집
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    • 제36권9호
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    • pp.33-44
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    • 2020
  • 순결 특성을 갖는 그라우트에 대한 경화 전 소성상태의 전단강도 특성을 분석하기 위하여 혼합물의 점도와 실내 베인전단시험을 수행하였다. 그라우트를 물-시멘트비(w/c) 별로 제조하고 전단강도시험을 실시하였다. 그라우트의 소성상태 전단강도는 물-시멘트비에 영향을 많이 받아 물-시멘트비가 낮을수록 초기에 높은 전단강도가 발현되었으며, 양생 시간이 길어질수록 높은 전단강도를 나타내었다. 최대전단강도는 그 값이 클수록 작은 회전각에서 발현되고, 최대전단강도 값이 작을수록 큰 회전각에서 발현되었다. 또한, 겔 상태의 그라우트는 최대 전단강도가 발현 이후 급격히 전단강도가 저하되고 베인날의 회전각이 약 70°~90°이후에는 일정한 수준으로 수렴되는 것을 확인할 수 있었다.

지오폴리머의 강도와 내구성에 영향을 미치는 요인에 대한 고찰 (Factors Effecting the Strength & Durability of Geopolymer Binder: A Review)

  • 온정권;김규용;사수이;이예찬;유하민
    • 한국건설순환자원학회논문집
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    • 제9권4호
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    • pp.460-468
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    • 2021
  • 이산화탄소 및 온실가스의 배출, 과도한 에너지 소비 및 천연자원의 고갈을 막기 위해 콘크리트의 대체재를 찾는 것은 건설업의 해결과제이다. 이러한 문제를 해결하기 위해, 콘크리트보다 환경친화적인 지오폴리머가 주목을 받고 있으며, 실제 시공을 목적으로 강도 및 내구성에 대한 연구가 진행되고 있다. 일반적으로, 지오폴리머의 강도 및 내구성은 알칼리 용액의 종류 및 농도, 전구물질, 양생 온도 및 시간 등 여러 요인에 따라 달라지며, 이는 지오폴리머의 강도와 내구성에 영향을 미치는 화학조성 및 미세구조에 큰 영향을 미친다. 기존의 연구에서 최적의 알칼리 용액의 종류 및 농도, 전구물질, 양생 온도 및 시간을 통하여 지오폴리머의 압축강도 및 내구성이 향상되는 것을 확인하였으며, 본 연구에서는 과거의 연구 결과를 검토하고 이러한 요인이 지오폴리머의 압축강도 및 내구성에 미치는 영향을 체계적으로 종합하였다.

노출환경 조건이 자기치유형 보수 모르타르 시험체의 균열 치유성능에 미치는 영향 (Influence of Exposure Environmental Conditions on the Crack Healing Performance of Self-healing Repair Mortar Specimens)

  • 이웅종;이현호;안상욱;이광명
    • 한국건설순환자원학회논문집
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    • 제6권4호
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    • pp.283-288
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    • 2018
  • 균열 자기치유 소재는 균열발생 시점부터 노출환경 조건에 따라 활성화되기 때문에 치유성능과 균열면의 노출환경 조건과의 관계 규명이 매우 중요하다. 이에 본 연구에서는 자기치유형 보수 모르타르의 치유성능에 노출환경 조건이 미치는 영향을 투수시험을 통하여 조사하였다. 균열시험체의 초기 균열폭에 대한 온도 및 습도의 영향을 조사한 결과, 양생온도의 영향은 미미하였으나, 건습변화에 의해서는 균열닫힘 현상이 발생하고 있음을 확인하였다. 그리고 자기치유형 보수 모르타르 시험체의 균열부위에서 생성된 치유물질은 calcite 광물로 확인되었다. 밀도가 높은 calcite 광물은 중력의 영향을 받아 침강하기 때문에, 균열면의 방향에 따라 치유성능에 다소 차이를 나타냈으며, 또한 대기노출 조건보다 습윤노출 조건에서 치유성능이 크게 향상되었다.

The influence of nanofillers on the properties of ethanol-solvated and non-solvated dental adhesives

  • da Cruz, Leonardo Bairrada Tavares;Oliveira, Marcelo Tavares;Saraceni, Cintia Helena Coury;Lima, Adriano Fonseca
    • Restorative Dentistry and Endodontics
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    • 제44권3호
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    • pp.28.1-28.10
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    • 2019
  • Objectives: The aim of this study was to evaluate the influence of different concentrations of nanofillers on the chemical and physical properties of ethanol-solvated and non-solvated dental adhesives. Materials and Methods: Eight experimental adhesives were prepared with different nanofiller concentrations (0, 1, 2, and 4 wt%) and 2 solvent concentrations (0% and 10% ethanol). Several properties of the experimental adhesives were evaluated, such as water sorption and solubility (n = 5, 20 seconds light activation), real-time degree of conversion (DC; n = 3, 20 and 40 seconds light activation), and stability of cohesive strength at 6 months (CS; n = 20, 20 seconds light activation) using the microtensile test. A light-emitting diode (Bluephase 20i, Ivoclar Vivadent) with an average light emittance of $1,200mW/cm^2$ was used. Results: The presence of solvent reduced the DC after 20 seconds of curing, but increased the final DC, water sorption, and solubility of the adhesives. Storage in water reduced the strength of the adhesives. The addition of 1 wt% and 2 wt% nanofillers increased the polymerization rate of the adhesives. Conclusions: The presence of nanofillers and ethanol improved the final DC, although the DC of the solvated adhesives at 20 seconds was lower than that of the non-solvated adhesives. The presence of ethanol reduced the strength of the adhesives and increased their water sorption and solubility. However, nanofillers did not affect the water sorption and strength of the tested adhesives.

Mechanical behaviour of waste powdered tiles and Portland cement treated soft clay

  • Al-Bared, Mohammed A.M.;Harahap, Indra S.H.;Marto, Aminaton;Abad, Seyed Vahid Alavi Nezhad Khalil;Mustaffa, Zahiraniza;Ali, Montasir O.A.
    • Geomechanics and Engineering
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    • 제19권1호
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    • pp.37-47
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    • 2019
  • The main objective of this study is to evaluate and compare the efficiency of ordinary Portland cement (OPC) in enhancing the unconfined compressive strength of soft soil alone and soft soil mixed with recycled tiles. The recycled tiles have been used to treat soft soil in a previous research by Al-Bared et al. (2019) and the results showed significant improvement, but the improved strength value was for samples treated with low cement content (2%). Hence, OPC is added alone in this research in various proportions and together with the optimum value of recycled tiles in order to investigate the improvement in the strength. The results of the compaction tests of the soft soil treated with recycled tiles and 2, 4, and 6% OPC revealed an increment in the maximum dry density and a decrement in the optimum moisture content. The optimum value of OPC was found to be 6%, at which the strength was the highest for both samples treated with OPC alone and samples treated with OPC and 20% recycled tiles. Under similar curing time, the strength of samples treated with recycled tiles and OPC was higher than the treated soil with the same percentage of OPC alone. The stress-strain curves showed ductile plastic behaviour for the untreated soft clay and brittle behaviour for almost all treated samples with OPC alone and OPC with recycled tiles. The microstructural tests indicated the formation of new cementitious products that were responsible for the improvement of the strength, such as calcium aluminium silicate hydrate. This research promotes recycled tiles as a green stabiliser for soil stabilisation capable of reducing the amount of OPC required for ground improvement. The replacement of OPC with recycled tiles resulted in higher strength compared to the control mix and this achievement may results in reducing both OPC in soil stabilisation and the disposal of recycled tiles into landfills.