• Tribology and Lubricants
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• v.16 no.5
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• pp.332-340
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• 2000

The reduction of sulfur content in the diesel fuel has caused the poor lubricity of diesel fuel in the distributor type injection pumps of diesel engines that use the diesel for lubrication of their moving parts. To investigate the reason for poor lubricity of low sulfur diesel fuels, the wear scar diameters by HFRR (High Frequency Reciprocating Rig) were measured on the diesel fuels from Korean markets and the results were compared with their physical and chemical properties. Also, the lubricity change and the improvement effects on lubricity additives for the ultra low sulfur diesel fuel, were made experimentally, that will be regulated to a maximum of 0.005 wt% from about 2005 were evaluated. As a result, a good correlation was found between the wear scar diameter and the polyaromatic compound which includes heterocyclic compound in the diesel fuel. It was also found that the content of polyaromatic compound including heterocyclic compound was affected by the amount of desulfurization treatment fraction. And the lubricity additives with ester base were more effective than that with acid base on the ultra low sulfur diesel fuel. Therefore, it is suggested that the factors affecting the lubricity stated above should be taken into account to improve the lubricity property of the diesel fuel in the refining process.

• Journal of Conservation Science
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• v.2 no.2 s.2
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• pp.15-24
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• 1993

To understand the morphological change of ancient woods, samples classified by cell type, burial environment and species were collected and observed using microscopy. Decay of wood by cell type could classified into two types. First, degraded secondary wall was formed granular residues in $S_2$ layer and was remained $S_3$ layer and compound middle lamella. Second, the cell wall was slightly degraded and cracked in secondary wall. A gradual thinning of cell wall was occured. The compound middle lamella was separated from secondary wall. The resistance of degradation is increased at vessels, parenchyma, and tracheid and wood fiber in the order named. The type of degradation by species could be classified into four types. Overall degradation type; the degradation of cell wall is usually heavy and the extent of degradation Varies by part of the same sample. Partial degradation type ; this type shows severely different decay type by part of the sample. Nondegraded cells were mixed with degraded cells on the same sample. Erose degradation type ; thinning of the cell wall was occoured and the degradation type was different by part. Slight degradation types ; secondary wall was slightly degraded, cracked and separated from compound middle lamella. Considering different type of burial environment, dry wood was similiar to sound wood and slightly decayed. Waterlogged and peat burial wood was heavilydecayed. Between species of under the same environment, decay type and extent were diferentiated from each other.

• Journal of the Korean Society of Costume
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• v.55 no.5 s.95
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• pp.65-77
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• 2005

This stuffy is to understand the symbolic meaning of Korean traditional animal Patterns, to analyze their figurative characteristics focusing on fabric relics of Chosun Dynasty, and to search their internal beauty as well as their external beauty. Animal patterns can be classified as Individual type, the type that only animal patterns are used, and Compound type, the type that animal patterns are used with other patterns. The Individual type was not found at all. Only the Compound type, compounded with two or three other patterns, were found. Among the other patterns used in the Compound type, botanical patterns and heaven-and-earth-shaped patterns were the majority while letters patterns were rarely used. Bird patterns take enormously large part of the animal patterns. In terms of the arrangement, animal patterns are classified as Dense type, Sparse type, and Picturesque type.'rho three types are almost equal in their quantity. Picturesque type is found comparatively a lot. Animal patterns are much more frequently used in female clothes than in male clothes. For female clothes, they are mostly used in some parts of the clothes with ornamental effect. But, for male clothes, they are mainly used all over the fabric by weaving animal patterns on it. Not just their external beauty, animal patterns have also internally beautiful characteristics, such as keeping away from wicked ghosts, hoping for good luck, emblematic features, having ideological meanings, and so on.

• Journal of the Korean Chemical Society
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• v.38 no.12
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• pp.864-872
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• 1994

Absorption spectra of thermochromic spiropyran and spirooxazine derivatives were investigated. The effects of solvent polarity on the absorption spectra indicate that the merocyanine-like form of non-substituted spiro compound is likely to the quinoid type. However, the merocyanine-like form of electron-withdrawing substituted spiro compound is likely to the zwitter-ion type. The enthalpy changes between the closed and merocyanine-like forms were measured. The enthalpy change of spiro compound decreases as the solvent polarity increases. The UV-Vis spectrum of merocyanine-like form was resolved into three Lorentzian-Gaussian product bands. The solvent dependence of the amount of the three band was also examined.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.1
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• pp.111-116
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• 2002

This report describes an inhibitory effect of Tongku-tang(TKT) on mast cell-mediated immediate-type allergic reactions. TKT is an Oriental herbal prescription, which has been successfully applied for the treatment of allergic disorders, mainly skin anaphylactic diseases in eastern medicine. TKT has concentration-dependently inhibited the ear swelling response induced by intradermal injection of non-specific mast cell degranulator compound 48/80 in mice. TKT also inhibited mast cell-dependent passive cutaneous anaphylaxis activated by dinitrophenyl (DNP)-IgE antibody in rats. I studied the effect of TKT on the histamine and β-hexosaminase release from the rat peritoneal mast cells by compound 48/80. TKT did not inhibit significantly the histamine and β-hexosaminase release from the rat peritoneal mast cells by compound 48/80. However, TKT inhibited both TNF-α and IL-1β secretion induced by phorbol 12-myristate 13-acetate and A23187 respectively. These results provide evidence that TKT may be beneficial in the treatment of immediate-type allergic reaction.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.1 s.178
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• pp.129-135
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• 2006

In this study, a two-axis ultra-precision stage driven by piezoelectric elements is presented. The stage has a flexure-type parallel linear guide mechanism consisting of quad-symmetric simple parallel linear springs and quad-symmetric double compound linear springs. While the simple parallel linear springs guide the linear motion of a moving plate in the stage, the double compound linear springs follow the motion of the simple parallel linear spring as well as compensate the parasitic motions caused by the simple parallel linear springs. The linear springs are designed by rectangular beam type flexures that are deformed by bending deflection rather than axial extension, because the axial extension is smaller than the bending deflection at the same force. The designed guide mechanism is analyzed by finite element method(FEM). Then two-axis parallel linear stage is implemented by the linear guide mechanism combined with piezoelectric elements and capacitance type displacement sensors. It is shown that the manufactured ultra-precision stage achieves 3 nm of resolution in x- and y-axis within 30 ${\mu}m$ of operating range.

• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.819-822
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• 2003

Polyketides are an extensive class of secondary metabolites with diverse molecular structures and biological activities. A plasmid-based minimal polyketide synthase (PKS) expression cassette was constructed using a subset of actinorhodin (act) biosynthetic genes (actI-orfl, actI-orf2, actI-orf3, actIII, actⅦ, and actIV) from Streptomyces coelicolor, which specify the construction of an orange-fluorescent anthraquinone product aloesaponarin II, a type II polyketide compound derived from one acetyl coenzyme A and 7 malonyl coenzyme A extender units. This system was designed as an indicator pathway in S. parvulus to generate a hybrid type II polyketide compound via gene-specific replacement. The act ${\beta}-ketoacyl$ synthase unit (actI-orfl and actI-orf2) in the expression cassette was specifically replaced with oxytetracycline ${\beta}-ketoacyl$ synthase otcY-orfl and otcY-orf2). This plasmid-based hybrid PKS cassette generated a novel orange-fluorescent compound structurally different from aloesaponarin II in both S. lividans and S. parvulus. In addition, several additional distinctive blue-fluorescent compounds were detected, when this hybrid PKS cassette was expressed in S. coelicolor B78 (actI-orf2 mutant), implying that the expression of plasmid-based hybrid PKS cassette in Streptomyces species should be an efficient way of generating hybrid type II polyketide compounds.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.13 no.1
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• pp.116-128
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• 2000

Anal therapy is another way of taking medicine It is a traditional pathway but not available in common situation. Nevertheless. It has many benefit and usefulness, it has not treated so much. The dried immature fruit of Poncirus trifoliata L(Ji-Sil) is widely used to treat urticaria, itch and indigestion in traditional Korean Medicine. So this study was carried out to examine the effect of an aqueous extract from immature fruit of Poncirus trifoliate L. on immediate-type allergic reaction by anal administration. Anal administration of Poncirus trifoliata L. showed a marked inhibition rate in systemic immediate-type allergic reaction with a dose of 0.1 - 1 g/kg 1 hr before intraperitoneal injection of compound 48/80. Anal administration of Poncirus tnjoliata L. (0.1 -1 g/kg) significant1y reduced plasma histamine contents induced by compound 48/80. Anal administration of Poncirus trifoliata L. (10 g/kg) also inhibited to $44.6\%$ (P<0.01) local allergic reaction activated by anti-dinitrophenyl (DNP) IgE. In addition, Syzygium aromaticum dose-dependently inhibited the histamine release from the peritoneal mast cells by compound 48/80 or anti-DNP IgE. These results provide evidence that anal therapy of Poncirus trifoliata L. may be beneficial in the treatment of systemic and local immediate-type hypersensitivity by inhibition of histamine release from mast cells in vivo and in vitro.

• Journal of the Korean Statistical Society
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• v.25 no.4
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• pp.545-556
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• 1996

In this paper, we introduce a new concept of partial ordering which permits us to compare pairs of the dependence structures of a new hitting times for POD multivariate vector process of interest as to their degree of POD-ness. We show that POD ordering is closed under convolution, limit in distribution, compound distribution, mixture of a certain type and convex combination. Finally, we present several examples of POD ordering processes.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.201.2-201.2
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• 2003

A novel lanostane-type triterpene, (24E)-3,4-seco-9${\beta}$H-lanosta- 4(28),7,24- triene- 3,26- dioic acid was isolated from Abies koreana (Pinaceae) which is a tall evergreen tree grown indigenously in southern Korea. The structure of this compound was characterized by spectroscopic methods. Cytotoxicity of the compound was evaluated in vitro using the SRB method, and it showed marginal activity against human cancer cell lines.