• Applied Chemistry for Engineering
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• v.20 no.5
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• pp.479-485
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• 2009

In this study, basic physical properties were measured for ASCO EQ85 cationic surfactant of triethanolamine-ester quaternary ammonium salt and effect of pH on softening performance on fabrics was investigated using zeta potential measurement and adsorption experiment by quartz crystal microbalance. The CMC of the surfactant was near $3{\times}10^{-3}mol/L$ and the surface tension at CMC was about 40 mN/m. The interfacial tension measurement between 1 wt% aqueous solution and n-dodecane measured by spinning drop tensiometer showed that interfacial tension slightly increased with an increase in pH but the equilibration time was not affected by pH. The surfactant adsorption was found to increase with an increase in surfactant concentration and was also affected by pH of surfactant solution. The friction factor for fabrics treated with ASCO EQ85 surfactant was shown to increase with pH and better softening effect was found under acidic conditions. Half-life for foams generated with ASCO EQ85 surfactant solution increased with pH, which indicated an increase in foam stability with pH.

• Korean Chemical Engineering Research
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• v.46 no.2
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• pp.436-442
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• 2008

Organic-inorganic hybrid mesoporous anion-exchange resins were prepared for the adsorption of anions from aqueous solutions. The prepared samples were characterized using nitrogen adsorption-desorption measurements, Fourier transform infrared (FTIR) spectroscopy, and elemental analyses. Batch and kinetic experiments were performed to examine the anion-exchange performances of the prepared samples. Among the prepared samples, the hybrid mesoporous anion-exchange resins functionalized with tributylammonium groups showed higher adsorption capacities for perrhenate ions than did the resin functionalized with trimethylammonium groups. The surfactant, hexadecylamine, which had hydrophobic alkyl chains, also showed affinity for hydrophobic perrhenate anions.

• Journal of the Korean institute of surface engineering
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• v.39 no.6
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• pp.245-249
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• 2006

In this study, ternary Ti-Mo-N and new quaternary Ti-Mo-Si-N coatings were synthesized on steel substrates(AISI D2) and Si wafers by a hybrid coating system of arc ion plating (AIP) using Ti target and d.c. magnetron sputtering technique using Mo and Si targets in $N_2/Ar$ gaseous mixture. Ternary Ti-Mo-N coatings were substitutional solid-solution of (Ti, Mo)N and showed maximum hardness of approximately 30 GPa at the Mo content of ${\sim}10$. %. The Ti-Mo-Si-N coating with the Si content of 8.8 at. % was a composite consisting of fine (Ti, Mo)N crystallites and amorphous $Si_3N_4$ phase. The hardness of the Ti-Mo-Si(8.8 at. %)-N coatings exhibited largely increased hardness value of ${\sim}48$ GPa due to the microstructural evolution to the fine composite microstructure and the refinement of (Ti, Mo)N crystallites. The average friction coefficient of the Ti-Mo-Si-N coatings largely decreased with increase of Si content. The microstructures of Ti-Mo-Si-N coatings were investigated with instrumental analyses of XRD, XPS, and HRTEM in this work.

• The Korean Journal of Quaternary Research
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• v.17 no.1
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• pp.17-26
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• 2003

A hierarchy is defined as a system wherein its parts are interconnected with one another and the lower levels are constrained by the higher levels to various degrees, depending on the time constraints of the behavior. We illustrate that the concept of hierarchy is identified in the Baekdoodaegan frame, and that the Korean national area was hierarchically divided into many watersheds in many old maps. The Baekdoodaegan and Jeongmack were consistent with the hierarchy of climatic as well as spatial variables. It is evident from an old map that the concept was coined as early as in 1402. A typical configuration of Korean landscape, which was developed in the arrangement of village and surrounding landscape elements situated in a watershed, may be associated with the hierarchical approach to land and culture. Although current practices based on the concept are meaningful, further diverse studies are needed to improve ideas.

• The Korean Journal of Quaternary Research
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• v.18 no.2 s.23
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• pp.5-16
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• 2004

The geomorphic deformation of the alluvial fans by tectonic movement was investigated along the lineaments of the northem part of the Ulsan(Bulguksa) fault system. Based on the aerial photographs interpretation and field surveys Ulsan fault system was identified as an active reverse fault which has displaced the Quatemary fan deposits. Buguksa fault system strikes for the direction of NW-SE and N-S. These two lineaments of active fault are crossing at Jinty village in Gyeongju city and the fault plane forms here almost vertical dip. The lateral pressures from the two directions have possibly influenced on the formation of the vertical dip at jinty villagy. It should be resulted from that the two pressures responsible for the active reverse fault at which the one with the NW-SE strike thrusts the hanging wall of Tohamsan block southwestward and the other pressure with the N-S strike thrusts it westward over the foot wall of the fan deposits. The marine oxygen isotope stage 8(0.30-0.25 Ma. BP) and stage 6(0.20-0.14 Ma. BP) are presumed to be the ages of high and middle surfaces of the alluvial fan, repectively. The vertical displacements on the high surfaces along the Bulguksa fault system are about 1.05 m at Ha-Dong, 9.5-10.5 m at Jinhyun-Dong, and about 10 m high at Jinty village. And the vertical displacement on the middle surface was measured about 6 m high at Ha-Dong. The average slip rate of vertical displacements is calculated about 0.03-0.43 mm/y.

• Journal of the Korean Geographical Society
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• v.34 no.3
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• pp.231-246
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• 1999

The geomorphic deformation of the alluvial fans by tectonic movement was investigated along the lineaments of the northern part of the Bulguksa fault system. Based on the aerial photographs interpretation and field surveys Bulguksa fault system was identified as an active reverse fault which has displaced the Quaternary fan deposits. Bulguksa fault system strikes for the direction of NW-SE and N-S. These two lineaments of active fault are crossing at Jinty village in Kyungju city and the fault plane forms here almost vertical dip. Thelateral pressures from the two directions have possibly influenced on the formation of the vertical dip at Jinty village. It should be resulted from that the two pressures responsible for the active reverse fault at which the one with the NW-SE strike thrusts the hanging wall of Tohamsan block southwestward and the other pressure with the N-S jstrike thrusts it westwrd over the foot wall of the fan deposits. The marine oxygen isotope stage 8(0.30-0.25 Ma. BP) and stage 6(0.20-0.14 Ma. BP) are presumed to be the ages of high and middle surfaces of the alluvial fan, repectively. The vertical dispiacements on the high surface along the Bulguksa fault system are about 10.5m at Ha-dong, 9.5-10.5m at Jinhyun-dong, and about 10m at Jinty village. And the vertical displacement on the middle surface was measured about 6m high at Ha-dong. The average slip rate of vertical displacements is calculated about 0.03-0.043mm/y.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.284.3-285
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• 2002

Paraquat(methyl viologen) is a bis-quaternary ammonium compound as a wide range herbicide. which was first introduced as an oxidation-reduction indicator dye. When paraquat(fatal dose. 1-2g) was administered to men, the oxido-reduction system of cell was repeatedly acted to perpetuate the cell membrane system, Many death cases had been occurred after ingestion of paraquat around Daejon area for the last six months. (omitted)

• Journal of Pharmaceutical Investigation
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• v.23 no.3
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• pp.41-50
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• 1993

The iontophoretic delivery across rat skin of quaternary ammonium salts (isopropamide: ISP, pyridostigmine: PS), which are positively charged over a wide pH range, was measured ill vitro. The study showed that: (a) iontophoresis significantly enhanced delivery of ISP and PS compared to respective passive transport; (b) delivery of ISP and PS was directly proportional to the applied continuous direct current density over the range of $0-0.69\;mA/cm^2;$ (c) delivery of ISP and PS was also proportional to the drug concentration in the donor compartment over the range of $0-2{\time}l0^{-2}M:$ (d) sodium ion in the donor compartment inhibited the drug transport possibly due to decreasing the electric transference number of the drug; (e) delivery of ISP and PS increased as the pH of the donor solution increased over the pH range 2-7 suggesting permselective nature of the epidermis, and inhibition of the transference number of the drugs by hydronium ion; (f) some organic anions such as taurodeoxycholate, salicylate and benzoate which form lipophilic ion-pair complexes with ISP inhibited the delivery of ISP. The degree of inhibition by the organic anions was linearly proportional to the extraction coefficient $(K_e)$ of ISP from the partition system with each counteranion between phosphate buffer (pH 7.4) and n-octanol. For PS, however, taurodeoxycholate, but not salicylate and benzoate inhibited the iontophoretic delivery. It suggests that not only sodium ion and hydronium ion but also the counteranions which form lipophilic ion-pairs with quaternary ammonium drugs are not favorable components in formulating the donor solution of the drugs to achieve an effective iontophoretic delivery.

• Applied Microscopy
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• v.25 no.3
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• pp.82-89
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• 1995

High resolution transmission electron microscopic observations on quaternary $Zn_{1-x}Mg_{x}S_y$ $S_{1-y}$(x=0.13, y=0.16) on (001) GaAs substrate grown up to $1.2{\mu}m$ with 20nm ZnSe buffer layer at $300^{\circ}C$ by RIBER MBE system which has a single growth chamber were investigated by HRTEM working at 300kV with point resolution of 0.18nm. The ZnSe buffer layer maintains the coherency with the GaAs substrate. The stacking faults had begun at ZnSe buffer/$Zn_{1-x}Mg_{x}S_{y}S_{1-y}$ interface, whose length and spacing became larger than 60nm and wider than 40nm, respectively. The inverse triangular stacking fault was bounded by stacking faults which were formed on {111} planes with different variants. There exists rare stacking faults inside the triangular defect. The epilayer surrounded by the straight stacking faults, which had formed in the same direction, became the columnar structure.

• Journal of The Geomorphological Association of Korea
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• v.17 no.3
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• pp.1-16
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• 2010

Phytoliths, silica microfossil that produced within and between cells and tissues of plants are especially yielded in Gramineae with many different forms and can attribute to the reconstruction of climatic and environmental changes and agriculture activity of the Quaternary. The phytoliths in soil can remain for long periods of time, because of strong resistance to physical and chemical weathering. The spatial range of study is too small due to deposition of phytoliths directly to the soil. There are difficulties of phytoliths identification because of multiplicity and redundancy, so far uniform and exact classification scheme has not been adopted. Therefore we attempted phytolith classification system applied to Korea. The paleoenvironmental reconstruction research using phytholith are applicated in many parts of studies. Also high-resolution paleoclimatic reconstruction expected to be possible using phytolith indices of Iph and Ic as well as climatic indicator of phytolith morphology.