• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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• pp.393-394
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• 2010

본 논문은 고압송용 저점도 고유동 콘크리트를 개발하기 위한 연구의 일환으로 페이스트 및 모르타르의 소성점도 및 항복응력을 검토하였다. 이 연구를 통하여 고압송용 저점도 고유동 콘크리트에 페이스트 및 모르타르의 적절한 재료특성을 검토하고자 한다.

• 한국자기학회지
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• 제5권5호
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• pp.667-671
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• 1995

The viscometric technique is used to study the effects of microstructure on the viscosity (viscosity vs. concentration or shear rate) of magnetic particle suspensions. In this characterization, measurement of suspension viscosity is used to obtain the dependence of viscous energy dissipation on microstructural state of dispersions. Microstructural shape effects which are related to particle orientation are then indirectly obtained. Empirical formulas from mean field theory and the Mooney equation, which are applicable at high concentration of magnetic particles, are used to relate viscosity to particle concentration. The validity and physical meaning of these equations are discussed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.791-792
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• 2008

• Bulletin of the Korean Chemical Society
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• 제11권1호
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• pp.28-31
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• 1990

By using Pak's theory of liquid, a phenomenological theory of viscosity proposed by the authors is applied to liquids under high pressures. The calculated viscosities for various simple substances are in good agreements with those of the observed values over wide pressure ranges.

• 접착 및 계면
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• 제11권3호
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• pp.89-99
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• 2010

본 논문에서는 poly(vinyl acetate-co-ethylene)을 산화, 환원 방법으로 중합할 때 poly(vinyl alcohol) (PVOH)이 최종 에멀젼의 물성에 미치는 영향과 pH의 변화가 최종 에멀젼의 물성에 미치는 영향에 대하여 알아보았다. 실험 결과 PVOH의 분자량이 에멀젼 성질에 크게 영향을 미쳤다. 분자량이 낮은 PVOH 이용 시는 점도가 낮은 제품을 얻었고, 분자량이 큰 PVOH를 이용 시는 높은 점도의 제품을 얻었다. 그러나 pH를 변화 시키면서 중합한 제품의 최종 성질은 PVOH에 대하여 다른 결과를 얻었다. 일반적으로 중합도가 높고 부분 검화물의 PVOH를 이용한 poly(vinyl acetate) 에멀젼 최종점도는 상대적으로 매우 높은 점도를 유지하는 데 비하여, VAE 에멀젼에서는 높은 pH에서 합성 시에는 낮은 에멀젼의 점도를 얻었다. 이것은 에멀젼 합성 중에 PVOH의 분자량의 저하에 의한 영향으로 판단된다. pH가 증가 할수록 그라프트율이 감소하고, 분자량이 감소하면서 점도가 낮아진다는 결과를 얻었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2005년도 추계 학술논문 발표대회
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• pp.71-74
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• 2005

The viscosity of high-flowability paste is very high compared to normal concrete for the low water-binder ratio(W/B). Therefore, high-flowability concrete is positively necessary to high-range water reducing agent. High-Flowability paste can make much higher fluidity with no occurrence of segregation, by its higher viscosity and lower yield value than normal concrete. The flowability of high-flowability paste must be evaluated not only by convention consistency test such as slump test but also by the base of the rheological properties of the fresh concrete. The purpose of this study is to analyze the fluidity of high-flowability paste according to the addition ratio of the Melamine Sulphonate high-range water reducing agent.; high-flowability paste is considered as Bingham plastic fluid with the rheology parameters of the plaste viscosity and yield value.

• E2M - 전기 전자와 첨단 소재
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• 제8권5호
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• pp.587-593
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• 1995

Silicone oils used insulating substances exhibit the both of organic and inorganic properties, and it has many superior characteristics such as the high thermal resistance and low thermal oxidation level when compared to other insulation oils. In order to investigate the dielectric loss due to the increase of viscosity, silicone oils of viscosity 1, 2, 5[cSt] had been chosen as the specimen and experiment has been performed in the temperature range of -70[.deg. C] - 65[.deg. C] and frequency range of 30 - 1*10$\^$5/[Hz]. As a result, the linear decrease of loss at low frequency region in high temperature was due to the influence of applying frequency, whereas the increase of loss at high frequency region was contributed by electrode's resistance. And increasing viscosity, the activation energy increased from 3.77[kcal/mole] to 7.21[kcal/mole]. The dipole moment of specimen was become clear 1.48 - 2.26[debyel in high temperature region(5 - 65[.deg. C]) and 1.05 - 1.80[debye] in low temperature region (-70 - -25[.deg. C])respectively.

• 한국식품과학회지
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• 제33권2호
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• pp.195-199
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• 2001

Amylograph를 이용하여 방사선 조사된 검은후추가루의 amylograph characteristics의 변화를 검사하고, 변화된 amylograph characteristics에 의해서 검은후추가루의 검지가 가능한지를 알아보기 위하여 본 실험은 수행되었다. Initial pasting temperatures, maximum viscosity temperatures는 조사선량의 증가에 따른 유의적인 변화가 관찰되지 않았다. Maximum viscosity(P), $93^{\circ}C$ viscosity, $93^{\circ}C$에서 15분 후의 viscosity(H), $45^{\circ}C$ viscosity(C), $45^{\circ}C$에서 30분 후의 viscosity, $45^{\circ}C$에서 60분 후의 viscosity는 조사선량이 증가할수록 감소하는 경향을 보여주었으며, p<0.05의 수준에서 통계적인 유의성이 관찰되었다. 그러나 breakdown(P-H), setback(C-P), 그리고 consistency(C-H)는 조사선량의 증가에 따른 명확한 차이가 관찰되지 않았다. breakdown(P-H)이 0.75, setback(C-P)이 0.88, consistency(C-H)가 0.31의 $R^2$ 값을 보인 것을 제외하고는 모든 amylograph characteristics 의 $R^2$ 값은 0.97 이상의 높은 상관성을 보여 주었다. 따라서 amylograph characteristics에 의해서 검은후추가루의 방사선 조사여부 확인이 가능하였다.

• 한국건축시공학회지
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• 제4권2호
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• pp.129-136
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• 2004

High fluidity concrete(HFC) requires high dosage of superplasticizer to acquire sufficient fluidity, and high contents of fine powder and viscosity enhancing admixtures to resist segregation. The use of high amount of admixtures to make HFC at batcher plant in ready mixed concrete company is one of the reasons to raise the manufacturing cost of HFC. For this reason, new type of manufacturing method of HFC are described using both flowing concrete method and segregation reducing superplasticizer(SRS) in order to gain economical profit and offer the convenience for quality control.. As dosage of melamine based superplasticizer increases, it shows that fluidity and bleeding increase, while air contents and ratio of segregation resistance decrease. It also shows that addition of viscosity agent into superplasticizer reduce bleeding and improve segregation resistance of concrete. Dosage of AE agent into superplasticizer containing viscosity agent recovers loss of air contents during flowing procedure. Combination of proper contents of superplasticizer, viscosity agent and AE agent make possible to develope segregation reducing type superplasticizer. Compressive strength of high fluidity concrete applying flowing method with it is higher than that of base concrete. No differences of compressive strength between compacting methods are found. For the estimation of construction cost of high fluidity concreting using segregation reducing type superplasicizer, under same strength levels, although material cost of high fluidity concrete is somewhat higher than that of plain concrete due to segregation reducing type superplasticizer cost, labor cost and equipment cost of high fluidity concrete is cheaper than that of plain concrete. However, based on the strength differences, high fluidity concrete shows lower material cost, labor cost and equipment cost than that of plain concrete due to decreasing in size of member and re-bar caused by high strength development of concrete.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.355-356
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• 2002

The dielectric permittance and the dielectric loss factor of several lubricating oils were measured at frequencies from 100 Hz to 1.5 MHz. The measurements were carried out under atmospheric pressure as a function of temperature and under fixed temperature as a function of pressure. Temperature and pressure dependence of dielectric relaxation time were investigated. The temperature dependence of relaxation time obeyed the Vogel-Fulcher-Tammann (VFT) law. We modified the VFT equation in order to express the dielectric relaxation time as a function of temperature and pressure. Furthermore. by taking into consideration the similarity of the temperature and pressure dependence between dielectric relaxation and mechanical relaxation. the prediction of high-pressure viscosity were conducted. The predicted results were compared with the viscosity data obtained from the falling-sphere type viscometer.