• Tribology and Lubricants
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• 제28권2호
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• pp.81-92
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• 2012

To product multi-grade oil like engine oil, a sort of mineral base oil is mixed with a fundamental additive liquid package and a polymer liquid as viscosity index improver in order to improve the lubricating property of oil. That is, engine oil is the mixture of more than two fluids. In this paper, it will be systematically organized the governing equation describing non-Newtonian thermo-hydrodynamic lubrication related with the mixture of incompressible fluids based on the principle of continuum mechanics. Then, in order to find how the thermal analysis effect on the bearing performance lubricated with the mixture of multi-fluids, it will be compared to the performances between the mixture of each liquid to be blended and multi-grade engine oil as a single fluid in a high speed journal bearing. It is found that, in the case of lower viscosity oil, the difference of pressure distribution between the above two cases turns out to be existed, even if the load capacity is same level.

• 설비공학논문집
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• 제5권3호
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• pp.217-225
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• 1993

Nonflammable mixtures of flammable and nonflammable refrigerants are possible as substitute refrigerants for use in domestic heat pumps and refrigerators. Refrigerant leakage from such a system is of paramount concern since it is possible that the resulting mixture composition remaining in system will reside in the flammable range. This paper presents a simulation of a leakage process of refrigerant mixtures. Idealized cases of isothermal leakage process are considered in this study representing a slow leak. Simulation is performed for selected composition of binary and ternary refrigerant mixture; R-32/134a and R-32/125/134a. Mixture compositions with respect to percentage leak of original charge are presented. In isothermal leakage process, both vapor and liquid compositions of more volatile refrigerant decrease during vapor and liquid leak, but the total composition of this component decreases during vapor leak and increases during liquid leak. Vapor and liquid compositions are determined depending on the vapor-liquid equilibrium relation of the refrigerant mixture. The refrigerant mixture left in the system can go to a nonflammable direction relying on which component in the mixture is flammable.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.200-202
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• 2007

Improvement of LC mixtures can be realized by the development of new molecules in combination with the identification of advanced mixture concepts. By new high-polar single materials rotational viscosity has recently been improved significantly. Now, a new LC mixture concept for IPS and FFS technology has been identified which additionally improves switching time by up to 10%. This advanced concept is based on a more efficient usage of high-polar materials and Super Low Viscous (SLV) compounds and simultaneous reduction of less efficient materials.

• Nuclear Engineering and Technology
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• 제41권7호
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• pp.979-988
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• 2009

Tensioned metastable fluids provide a powerful means for low-cost, efficient detection of a wide range of nuclear particles with spectroscopic capabilities. Past work in this field has relied on one-component liquids. Pure liquids may provide very good detection capability in some aspects, such as low thresholds or large radiation interaction cross sections, but it is rare to find a liquid that is a perfect candidate on both counts. It was hypothesized that liquid mixtures could offer optimal benefits and present more options for advancement. However, not much is known about radiation-induced thermal-hydraulics involving destabilization of mixtures of tensioned metastable fluids. This paper presents results of experiments that assess key thermophysical properties of liquid mixtures governing fast neutron radiation-induced cavitation in liquid mixtures. Experiments were conducted by placing liquid mixtures of various proportions in tension metastable states using Purdue's centrifugally-tensioned metastable fluid detector (CTMFD) apparatus. Liquids chosen for this study covered a good representation of both thermal and fast neutron interaction cross sections, a range of cavitation onset thresholds and a range of thermophysical properties. Experiments were devised to measure the effective liquid mixture viscosity and surface tension. Neutron-induced tension metastability thresholds were found to vary non-linearly with mixture concentration; these thresholds varied linearly with surface tension and inversely with mixture vapor pressure (on a semi-log scale), and no visible trend with mixture viscosity nor with latent heat of vaporization.

• 한국가금학회지
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• 제45권1호
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• pp.29-39
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• 2018

본 연구는 기존의 춘천닭갈비의 기호도와 저장성을 향상 시키기 위하여 훈연액(0%, 0.05%, 0.1%, 0.2%)과 0.1% 훈연액이 포함된 염지제(0.2%, 0.3%)를 수준별 첨가하여 저장성 실험과 소비자 기호도 평가를 통해 최적의 비율을 확립하고자 하였다. 첫 번째 실험에서 훈연액 첨가는 색도에 영향을 주지 않았으나 pH 값을 다소 증가시켰고, 전자코를 이용한 향기패턴 분석결과, 훈연액 첨가수준에 따라 향의 강도가 증가하여 명확한 차이를 나타냈다. 소비자 기호도 평가 결과, 0.1% 훈연액이 가장 높은 기호도 점수를 받았다. 이를 토대로 두 번째 실험에서 염지제를 수준별 첨가하여 춘천닭갈비의 저장성 실험과 소비자 기호도 평가를 진행하였다. 색도는 양념육류의 특성상 명확한 차이를 확인할 수 없었고, 훈연액과 염지제 첨가는 저장말기에 급격한 pH 값의 감소를 억제하였고, TBARS 및 VBN 측정결과, 훈연액 단독 처리구보다 훈연액 및 염지제 처리구가 더 지방산화 및 단백질 변패를 억제하였으며, 0.3% 염지제 처리구에서 단백질 변패 억제력이 더 높았다. 훈연액 첨가는 대장균군과 일반 세균수의 증가를 억제하였고, 염지제 첨가수준이 증가할수록 더 높은 항균효과를 나타냈다. 하지만 소비자 기호도 평가 결과, 0.3% 염지제 첨가구의 기호도가 0.2% 염지제 첨가구에 비해 낮았다. 그러므로 저장성과 기호도가 향상된 춘천닭갈비를 제조할 때 저장성과 기호도를 고려해 0.1% 훈연액과 0.2% 염지제를 첨가하는 것이 권장된다.

• 한국임상수의학회지
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• 제36권3호
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• pp.159-165
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• 2019

Pimobendan is an inodilator used to treat canine heart failure, and pentoxifylline is reported to be beneficial for microcirculation and heart disease. The purpose of this study was to evaluate the pharmacokinetic and pharmacodynamic profiles of a novel pimobendan-pentoxifylline liquid mixture after oral administration to dogs. Eight healthy Beagle dogs were included in the study. The dogs were divided into the control group (orally administered water; n = 4) and experimental group (orally administered pimobendan-pentoxifylline liquid mixture [pimobendan 0.25 mg/kg, pentoxifylline 15 mg/kg]; n = 4). Plasma samples were obtained and echocardiographic indices were measured for 24 hours after administration. The concentrations of pimobendan and pentoxifylline were quantified by using a liquid chromatography-mass spectrometer (LC-MS). The elimination half-life ($T_{1/2}$) was $32.96{\pm}9.80mins$ for pimobendan and $29.49{\pm}6.67mins$ for pentoxifylline. The time to reach maximum concentration ($T_{max}$) were $52.50{\pm}31.22mins$ for pimobendan and $41.25{\pm}18.87mins$ for pentoxifylline. The maximum blood concentration ($C_{max}$) was $96.92{\pm}75.64ng/mL$ for pimobendan and $7074.07{\pm}3261.1ng/mL$ for pentoxifylline. Of the echocardiographic indices, fractional shortening (FS) and left ventricular internal diameter at end systole (LVIDs) were significantly altered at 1-3 hours after the administration of pimobendan-pentoxifylline liquid mixture. The pimobendan-pentoxifylline liquid mixture was well tolerated by the dogs, with no adverse effects observed during the study.

• 설비공학논문집
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• 제12권6호
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• pp.589-598
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• 2000

The vapor-liquid equilibrium and miscibility measurement apparatus was developed and used to obtain data for refrigerant/oil mixture. The vapor-liquid equilibrium and miscibility data for R-410a/POE32 and R-410A/POE46 oil mixtures are obtained over the temperature range from -20 to $60^{\circ}C\;with\;10^{\circ}C$ intervals and the oil concentration range from 0 to 90 wt%. Using the experimental data, an empirical model is developed to predict the temperature-pressure-concentration relations for R-410A/POE oil mixtures at equilibrium. In the R-410A/POE32 oil mixture, the average root-mean-square deviation between measured data and calculated results from the empirical model is 2.00% and in the R-410a/POE46 oil mixture, that is 3.69%. Flory-Huggins theory is also used to predict refrigerant/oil mixture behavior. Miscibility for R-410A/POE32 oil mixture was observed all over the experimental conditions. Immiscibility for R-410A/POE46 oil mixture was observed at the low oil concentrations(10~30 wt%).

• 한국가시화정보학회지
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• 제15권2호
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• pp.21-25
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• 2017

If a liquid droplet evaporates on a solid substrate, when it completely dries, it leaves a peculiar pattern, which depends on the composition of the liquid. Not only a single component liquid but also complex liquids are studied for a different purpose. In particular, a binary mixture droplet has been widely studied and used for an ink-jet printing technology. In this study, we focus on investigating to visualize the internal flow field of an ethanol-water mixture by varying a concentration ratio between two liquids. We measure the in-plane velocity vector fields and vorticities. We believe that this fundamental study about the internal flow field provides a basic idea to understand the dried pattern of the binary mixture droplet.

• Tribology and Lubricants
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• 제28권2호
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• pp.47-55
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• 2012

Generally, to product multi-grade oil like engine oil, a sort of mineral base oil is mixed with a fundamental additive package liquid and a polymer liquid as viscosity index improver in order to improve the lubricating property of base oil. That is, engine oil is the mixture of more than two fluids. Specially, a polymeric type liquid cannot be seen as the linear viscosity like Newtonian fluids. In this research, by using the governing equation describing non-Newtonian hydrodynamic lubrication related with the mixture of incompressible fluids based on the principle of continuum mechanics, it will be compared the bearing performance between the mixture of each liquid to be blended and multi-grade engine oil as a single fluid in a high speed hydrodynamic journal bearing. Further, it is to be found the way estimating the performance of the blended multi-grade engine lubricant in a journal bearing in advance before blending by using the physical properties of mineral base oil, fundamental additive liquid and polymer liquid of viscosity index improver. So, it can be reduced the number of trial and error to get the wanted lubricant by selecting the proper volume fraction of each liquid to satisfy the expected performance and estimating in advance the performance of various multi-grade oils before blending. Therefore, it can be shorten the developing time and saved the developing cost.

• 대한금속재료학회지
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• 제56권12호
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• pp.870-877
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• 2018

Cyanex 272 shows the highest separation factor for the rare earth elements from hydrochloric acid solution among the organophosporus acidic extractants, D2EHPA and PC 88A. Solvent extraction of Tb(III) from weak hydrochloric acid solution with an initial pH 3 to 6 was compared with Cyanex 272, its mixture with Alamine 336, and ionic liquid with Aliquat 336. The solvent extraction reaction of Tb(III) using Cyanex 272 was the same as that of light rare earth elements. Synergism was observed for the extraction of Tb(III) by the mixture with Alamine 336 when the initial concentration ratio of Cyanex 272 to Alamine 336 was higher than 5. Use of the ionic liquid led to a great increase in the extraction percentage of Tb(III) from the same initial extraction conditions. While the equilibrium pH of the mixture was always lower than the initial pH, under some conditions extraction with the ionic liquid resulted in a higher equilibrium pH than the initial pH. The loading capacity of the mixture and the ionic liquid was the same and 2.6 times larger than that using Cyanex 272 alone. Ionic liquid was recommended as a suitable extractant for the extraction of Tb(III) from hydrochloric acid solution based on the ease of handling and higher extraction percentage.