• Polymer(Korea)
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• v.26 no.5
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• pp.575-581
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• 2002

Heterogeneous ion exchange membranes were prepared by mixing polyethylene as matrix with bead and fibrous anionic ion exchangers at different mixing ratio. Generally, ion exchange capacities were increased with increasing the ratio of the fibrous ion exchanger content. The highest ion exchange capacity of the membrane was 1.86 meq/g at 30wt% IXF (ion exchange fiber) in the membrane. The water uptake, fixed ion concentration, and ion transport number of the membrane increased with increasing the content of the fibrous ion exchanger. However, the electrical resistivity of the membrane was decreased with increasing the content of the fibrous ion exchanger. The lowest electrical resistivity of 5$\Omega$/$\textrm{cm}^2$ was observed at 30 wt%of IXF.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.12
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• pp.1043-1050
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• 2010

Fuel stratification and thermal stratification occur in the HCCI combustion chamber on a microscopic scale. They affect the ignition and combustion processes. In this study, the effect of the inhomogeneity in the mixture gas on the HCCI combustion process was investigated. Two-dimensional chemiluminescence images were captured using a framing camera to evaluate the flame structure. DME was used as the test fuel. First, the effect of inhomogeneity in the fuel distribution in the premixture was investigated for the four-stroke optically accessible engine. Then, by comparing the combustion of the homogeneous mixture in the rapid compression machine, which does not contain any residual gas, with the combustion in the four-stroke engine, the effect of inhomogeneity in temperature due to the residual gas was analyzed. The results showed that a time lag appears spatially in combustion under inhomogeneous conditions in the four-stroke engine. The spatial variation in the combustion without the residual gas in the rapid compression machine is less than that in the combustion in the four-stroke engine.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2002.05a
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• pp.97-99
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• 2002

• Proceedings of the KSEEG Conference
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• 2001.04a
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• pp.223-224
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• 2001

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.65-72
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• 2019

In this study, heterogeneous ion exchange membranes were prepared by casting method with various mixing ratios of PPO ion-selective solution and ion exchange resin. Then heterogeneous bipolar membranes were prepared by using this. The water content of heterogeneous cation and anion exchange membranes were 60~80% respectively, the ion exchange capacity was 2.81~3.26 meq/g, 2.31~2.74 meq/g and electrical resistances were $1.65{\sim}1.45{\Omega}{\cdot}cm^2$ and $1.55{\sim}1.05{\Omega}{\cdot}cm^2$. The tensile strength of heterogeneous bipolar membrane was lower than that of PPO resin before functionalization ($700Kg_f/cm^2$). The tensile strength of heterogeneous bipolar membrane with catalyst layer was lower than that of non-catalytic heterogeneous bipolar membrane. The water splitting voltage of the heterogeneous bipolar membrane with catalyst layer was low and stable at a minimum of 1.7~1.8 V, maximum 3.9~4.0 V, and the water splitting voltage of the non-catalytic heterogeneous bipolar membrane was constant at 3.8~4.0 V.

• The Journal of the Petrological Society of Korea
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• v.9 no.3
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• pp.142-168
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• 2000

The granites distributed in the Kyongsang basin contain the rocks which are different from the host rocks, and they are known as magic microgranular enclaves. The genesis of the magic micro-granular enclaves can be divided into four types: (1) rock fragments from country rocks; (2) cumulation of the early crystals in host magma or disruption of early chilled borders; (3) magma mingling; and (4) restite. These enclaves can be easily found in the granites around Mt. Wonhyo, Yangsan city. They are ellipsoidal in shape, and have phenocrysts might be originated from the host rocks and sharp contacts with the granites. Under the microscope, textures such as oscillation zoning, horn-blende-mantled quartz, rapakivi texture, and acicular apatite are observed, and these indicate that the enclaves were originated from magma and then produced by chilling. The evidences showing that the enclaves were formed by magma mingling are: (1) petrographical characteristics; (2) similarity of the compositions between the rim of plagioclase in the enclave and plagioclase in the granite; (3) linear trends of the major elements; (4) total REE content of the enclaves; and (5) Textural and compositional variations from rim to core in zoned enclaves. The magic end member of the enclave is regarded as the aphyric basaltic andesite in Mt. Sinbul-Youngchui area. The granites around Mt. Wonhyo experienced the magma mingling process which was produced by the injection of mafic magma at about 70 Ma, during the crystal differentiation, and then continued the crystallization. The equigranular granites and the micrographic granites in the study area are considered as the results after the magma mingling process.

• The Journal of the Petrological Society of Korea
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• v.14 no.1
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• pp.12-23
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• 2005

Cretaceous granitic rocks in the Waryongsan area occur as a stock and show compositional changes with altitude. They include mafic microgranular enclaves (MME) with various sizes and types. The MMEs present clear evidence of magma mingling such as supercooling zone, mantling texture and back veining. The granitic rocks are divided into porphyritic granite, porphyritic granodiorite and fined-grained granite by their petrographic characteristics and modal compositions. The MMEs are discriminated to quartzdioritie, quartzmonzodiorite and tonalite. They have varying areal proportions in each granitic rock-type: 10∼l5% in the porphyritic granite, about 50% in the porphyritic granodiorite, and about 20% in the fined-grained granite. SiO₂ contents shows compositional change of 61.2∼72.0wt.%. Mean SiO₂ contents have 61.7wt.% in the porphyritic granodiorite, 68.6wt.% in the porphyritic granite. and 71.9wt.% in the fined-grained granite, respectively. Major oxide contents of the granitic rocks linearly vary with SiO₂ contents from the porphyiritic granodiorite to the fine-grained granite on Harker diagrams. Linear compositional variations seem to have been caused by differential degrees of mingling between mafic magma and host granite. Where larger amount of mafic magma was injected into the host granitic magma, the two magmas reached to thermal equilibrium more quickly and eventually chemical mixing occurred to produce the composition of the porphyritic granodiorite. On the other hand. less amount of injected mafic magma would have been responsible for mechanical mixing to produce the compositions of the porphyritic granite and the fined-grained granite. Therefore, it is considered that the granitic rocks in the Waryongsan area experienced magmas mingling resulting from the injection of more mafic magma into differentiating granitic magma, and that the compositional changes of the granitic rocks were ascribed to the degree of mingling between the two magmas.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.342-346
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• 2002

불포화 층상 해안 대수층 내에서의 밀도 의존적 지하수 유동 및 염분 이동에 대한 연구를 위해 하나의 지하수 유동-용질 이동 연동 수치 모델이 제시되었다. 이 수치 모델은 밀도 의존적 지하수 유동 지배 방정식, 염분 이동 지배 방정식 및 농도와 밀도의 관계식, 그리고 유한 요소법에 기초하여 개발되었다. 서로 다른 두가지 성질의 불포화 대수층이 고려되었다. 하나는 사질토층 위에 점토층이 존재하는 층상 대수층이고, 다른 하나는 사질토층과 점토층이 혼합된 두가지 물질로 구성된 균질화된 대수층이다. 수치모델의 결과는 층상 불균질성 (layered heterogeneity)가 해안 대수층 내에서의 밀도의존적 지하수 유동과 염분 이동에 있어서 매우 중요한 역할을 하고 있음을 보여준다. 그러한 층상 불균질성의 효과는 사질토층과 점토층과의 현저한 수리학적 및 수리역학적 성질의 차이에 기인한다 따라서 실제 해안 대수층 내에서 관찰되는 점토층을 적절히 고려하는 것이 보다 합리적고 타당한 해안 대수층내에서의 밀도 의존적 지하수 유동 및 염분 이동 해석을 가능하게 할 것이다.

• The Journal of the Petrological Society of Korea
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• v.9 no.3
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• pp.187-203
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• 2000

Mafic microgranular enclaves (MME) occur in the granites from the Bohyunsan area. The host granites are generally of granodioritic and granitic compositions. The MME can be divided into magic mineral clusters, quartz diorite and diorite according to their occurrence. Halter variation diagrams show linear trends between the MME and the host granites. Though the rim compositions of plagioclase in the host granites and the MME are similar the core compositions of plagioclase in some host granites show abnormally high An content. The Mg/(Mg+Fe) ratio of hornblende in the host granites gradually increase from the core to the rim. The chemical composition of minerals in the host granites had been affected by more marc magma composition. The modelling of major elements of the MME and hybrid host granites also indicate that they result from simple mingling/mixing between a dioritic magma and the host granite magma. The MME are thus interpreted to be globules of a more mafic magma which intruded the granite magma. Partial equilibration has been achieved between the MME and the host granites after they were commingled with each other.

• Membrane Journal
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• v.26 no.2
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• pp.97-107
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• 2016

This study was carried out to prepare a heterogeneous cation exchange membrane by mixing polyvinylidene fluoride (PVDF), commercial cation exchange resin and sulfonated poly(phenylene oxide)(SPPO) in order to propose an optimum condition for the preparation, and to compare its properties with commercial membrane. Study results show that the ion exchange capacity and electrical resistance were outstanding when the ratio of polymer matrix was less than 30% comparing between PVDF-IER, PVDF-SPPO and PVDF-SPPO-IER. The tensile strength was confirmed that seemed a hard look was five times greater compared to the commercial heterogeneous membrane, despite the weak durability of PVDF resin. Therefore, when chemical and mechanical properties are considered, the optimum mixing ratio between PVDF, IER and SPPO was 30 : 70, at which electric resistance was measured as $3{\sim}5{\Omega}{\cdot}cm^2$, ion exchange capacity as 0.6~1.0 meq/g, while mechanical strength was in a range of $12{\sim}15kgf/cm^2$.