• Korean Journal of Materials Research
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• v.8 no.4
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• pp.328-336
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• 1998

In metal-carbon system with no mutual solubility between matrix and alloying elements as solid or liquid phases, Cu-C-X nanocomposite metal powders were prepared by high energy ball milling for solid-lubricating bronze bearings. Elemental powder mixtures of Cu-lOwt.%C- 5wt. %Fe and Cu- lOwt. %C- 5wt. %Al were mechanically alloyed with an attritor in an argon atmosphere, and then microstructural evolution of the Cu-C-X nanocomposite metal powders was examined. It has been found that after 10 hours of MA, the approximately 10$\mu\textrm{m}$ sized Cu-C- X nanocomposite metal powders can be produced in both compositions. Morphological characteristics and microstructural evolution of the Cu-C-X powders have shown a similar MA procedure compared to those of metal-metal system. As a result of X - ray diffraction analysis, diffraction peaks of Cu and C were broaden and peak intensities were decreased as a function of MA time. Especially, the gradual disappearance of C peaks in the X- ray spectra is proved to be due to the lower atomic scattering factor of C. The calculated Cu crystallite sizes in Cu- C- X nanocomposite metal powders by Williamson- Hall equation were about lOnm size, on the other hand, the observed ones by TEM were in the range of 10 to 30nm.

• Korean Journal of Materials Research
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• v.4 no.7
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• pp.775-782
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• 1994

Influence of $TiO_{2}$ addition on sintering behavior and microstructure of MgO-$ZrO_{2}$ composites was studied. $ZrO_{2}$ containing 3mol%Y203 was existed as a c-$ZrO_{2}$ phase due to the formation of solubility of MgO, $TiO_{2}$ and $ZrO_{2}$ when sintered $1400^{\circ}C$ for 2h. All the compositions employed exhibited a similar shrinkage behavior with an end-point shrinkage between 8.58 and 11.00%. The additlon of $TiO_{2}$ promoted densification and the bulk density of specimen containing 1.67wt% $TiO_{2}$ was 3.75g/$\textrm{cm}^3$(98% TD) when $1600^{\circ}C$ for 2h. The amount of solubilities of MgO and TiOz in $ZrO_{2}$ were 5.ti7wt% and 2.62wt%,respectively. They were partially segregated near $ZrO_{2}$ grain boundary in the form of Ti-compounds during cooling. This segregation resulted in the formation microcracks which decreased the bending strength.

• Korean Journal of Materials Research
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• v.3 no.3
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• pp.261-271
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• 1993

Functionally Gradient Materials(FGM) of 4.5Pb($Ni_{1/3}Nb_{2/3})O_3$-55PZT and PLZT(lO/70 /30, 11/60/40) were prepared. Its dielectric and piezoelectric strain properties were investigated. The FGM were pressed into A/B/ A configuration using two kinds of films, one layer(A) was eliminated from FGM by polishing after sintering at $l250^{\circ}C$, 2 hrs. The acrylic binder system was successfully applied for crack free film through doctor blade method. The thickness of gradent layer in FGM was about 30${\mu}$m. Dielectric properties of FGM show the average value of each side layer. The strain-electric field characteristics of FGM were significantly improved comparison with the other single compositions. The prepared FGM piezoelectric actuator shows about 3${\mu}$m/IOOV displacement.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.4
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• pp.415-423
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• 2015

Purpose: We conducted a study on the brand name types of optical shop in the region of Daegu to exploit the data necessary for a new brand naming. Methods: The characteristics of the names including the concept and function, phrasing compositions - whether the names are Korean words, English words or combination of the two, or others, and whether the names are descriptive, allusive or coined, alternative names, and most frequently used names were studied and analyzed. Results: For those in Korean words, the most frequently appeared consonant was 'ㅇ' then 'ㅅ'. In combination words, either in Korean and English combination or others, 57.1% of the names were in Korean, or 32.7% of the names were in English. As for number of syllables, 3 syllables consumed 30.4% and 2 and 4 syllables were in similar proportions of 29.7% and 25.0%, respectively. The proportions of allusive and descriptive names were 17.0% and 13.3%, respectively. As for alternative creation type, the type with combination of words came first, and then use of symbols came second. For other types, there were high number of brand names that contained the names of other business types and names of the districts in which the stores were located. Lastly, the most frequently used keyword was 'eye', which was used 45 times, and then came 'dang' and 'angyeong'. Conclusions: When starting a business and making an appropriate brand name, it must be easy to say and remember as well as meaningful. As such, a brand name for an optical shop should not only be creative, but also be associated with the business and emanate favorable impression.

• Korean Journal of Pharmacognosy
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• v.36 no.3 s.142
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• pp.164-170
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• 2005

In the present study, we investigated the mineral and metabolite composition and antioxidant activities in the flower, stem and root of Aster ciliosus Kitamura in order to detect biologically active substances and develop novel functional resources. The mineral and metabolite compositions differ significantly among the organ of Aster ciliosus Kitamura. The flower is composed of K as 827 mg/100g. while the stem and root are composed of Na as 654.64mg/100g and 771.70mg/100g, respectively. Contents of unsaturated fatty acids, such as oleic, linoleic, and linolenic acid, were higher than those of saturated fatty acid, such as palmitic acid in flower. The contests of phenolic compounds were measured at 285 nm using different solvents: 2.53 and 2.03 optical density (OD) in chloroform and 1.864 and 1.715 in ethanol extracts for the stem and root, respectively. Antioxidant activity was measured in 75% ethanol extracts: 41.3, 42.0 and $45.2\;{\mu}g/ml$ in stem, root and flower at $IC_{50}$ value, respectively. These results suggest that extracts from Aster ciliosus Kitamura can be potentially used as novel resources for antioxidant and biological active substances.

• Journal of Life Science
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• v.13 no.4
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• pp.529-534
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• 2003

This study was done to investigated the phytosterol compositions of safflower (Carthamus tinctorius L.) seed. The phytoestrogen activity was also determined using CAT-ELISA Kit in ethanol extract of safflower seed. The phytosterol of safflower seeds was identified using gas chromatography-mass spectrometry after saponification of the oils. The phytosterol content and composition of safflower seed oils were 4% and identified stigmast-5-en-3-ol (3$\beta$, 24S)-form, ${\gamma}$-sitosterol (clionasterol) with Wiley MS spectrum library. The synergistic effect of human estrogen receptor (hER) has been investigated using a minimal chimeric promoters composed of the TATA region of the adenovirus-2 major late promoter (A22MLP) and two consensus perfectly polindromic Xenopus vitellogenin A2 gene estrogen responsive elements (XVEREl19). Transient transfection experiments in tile human breast adenocarcinoma cell line MCF-7, which is known to express the estrogen receptor endogenously, revealed that phytoestrogen from Carthamus tinctorius L. acts as estrogen. We have observed the transcriptional activities stimulated methanol and ethanol extract of safflower seed in MCF-7, were 0.43 and 0.37 respectively, compared to that by $\beta$-estradiol as 1.0. Our data showed that safflower seeds have estrogenic activity methanol and ethanol extracts and ethanol lower than that of $\beta$-estradiol. This result provides the first evidence that the beneficial effect of safflower seeds may be mediated, at least in part, by the stimulating effect of phytoestrogen ell bone-protecting.

• Journal of Life Science
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• v.26 no.2
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• pp.247-252
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• 2016

Cultivated wild ginseng is a widely used dietary supplement and medicinal herb. The aim of this study was to optimize the ginseng using high performance liquid chromatography (HPLC)- charged aerosol detection (CAD) for ginsenoside analysis. CAD measures the physical property of an analyte and responds to almost all non-volatile species, independent of their nature, spectral properties, or particle size. It has become widely employed in pharmaceutical analysis. The cultivated wild ginseng extracts were analyzed for compositions of ginsenosides Rb1, Rd, Rg1, Rf, Re, and Rh1. The optimal analysis condition was set up from an experiment using a gradient. Ten grams of cultivated wild ginseng were extracted with 95% EtOH 100 ml for 24 hr at 80℃. The contents of the 6six major ginsenosides in the cultivated wild ginseng extract were Rb1 (5.48±0.12 mg/g), Rd (5.33±0.14 mg/g), Rg1 (12.80± 0.05 mg/g), Rf (19.08±0.68 mg/g), Re (19.87±0.05 mg/g), and Rh1 (16.47±0.16 mg/g), respectively. HPLC showed that the protopanaxatriol group (Rg1, Rf, Re, Rh1) had more content than the protopanaxadiol group (Rb1, Rd) in cultivated wild ginseng extract. In summary, the ginsenosides were identified with HPLC-CAD analysis, and their presence and quantity imply the importance of quality control, as well as the pharmacological activity of the ginseng root.

• The Journal of Korean Medical History
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• v.28 no.2
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• pp.37-45
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• 2015

Objectives : A quantitative analysis on the vocabulary in the English translation version of Donguibogam. Methods : This study quantitatively analyzed the English-translated texts of Donguibogam with the Corpus-based analysis, and compared the quantitative results analyzing the texts of original Donguibogam. Results : As the results from conducting the corpus analysis on the English-translation version of Donguibogam, it was found that the number of total words (Token) was about 1,207,376, and the all types of used words were about 20.495 and the TTR (Type/Token Rate) was 1.69. The accumulation rate reaching to the high-ranking 1000 words was 83.54%, and the accumulation rate reaching to the high-ranking 2000 words was 90.82%. As the words having the high-ranking frequency, the function words like 'the, and of, is' mainly appeared, and for the content words, the words like 'randix, qi, rhizoma and water' were appeared in multi frequencies. As the results from comparing them with the corpus analysis results of original version of Donguibogam, it was found that the TTR was higher in the English translation version than that of original version. The compositions of function words and contents words having high-ranking frequencies were similar between the English translation version and the original version of Donguibogam. The both versions were also similar in that their statements in the parts of 'Remedies' and 'Acupuncture' showed higher composition rate of contents words than the rate of function words. Conclusions : The vocabulary in the English translation version of Donguibogam showed that this book was a book keeping the complete form of sentence and an Korean medical book at the same time. Meanwhile, the English translation version of Donguibogam had some problems like the unification of vocabulary due to several translators, and the incomplete delivery of word's meanings from the Chinese character-culture area to the English-culture area, and these problems are considered as the matters to be considered in a work translating Korean old medical books in English.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.1
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• pp.22-28
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• 2004

Since the used materials of furnace heater tube with different kinds of thermal degradation were not commonly available, the HK-40 steel specimens were heat-treated isothermally at elevated temperature to simulate the microstructure at the service temperature. HK-40 steel specimens with five different aging time were prepared by isothermal heat treatment at $1050^{\circ}C$. The characteristics of the magnetic susceptibility have been investigated for the degradation evaluation of HK-40 steel. The magnetic susceptibility at room temperature increases as the extent of degradation of the materials increases. The variation of magnetic susceptibility was compared with the variation of tensile properties and Vickers hardness. To investigate the effect of the microsturctural change on the characteristics of tensile properties, hardness and magnetic susceptibility, the microstructures were examined by a scanning electron microscope(SEM) and the chemical compositions were analyzed by a energy spectrometer of SEM. As a result, the magnetic susceptibility method can be suggested as one of the nondestructive evaluation methods for the degradation of the HK-40 steel.

• Korean Journal of Organic Agriculture
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• v.18 no.2
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• pp.209-219
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• 2010

This study was carried out to evaluate the effects of applying levels of organic liquid fertilizer (OLF) on growth and fruit quality of hot pepper. The OLF was made with compositions of chicken dung : rice bran : soybean meal (2:1:1). Hot pepper was applied with 5 treatments; control (chemical fertilize), OLF-1.0X (standard applying levels), OLF-0.7X (70% of standard applying level), and OLF-1.3X (130% of standard applying level). The plant height was reduced at 23cm in the OLF-1.0X treatment compared to control of 293cm. The number of hot pepper fruits was significantly increased. The content of capsaicin in the ripened pepper decreased by 23.6% in the OLF-1.0X treatment with $253mg{\cdot}kg^{-1}$ compared with control of $331mg{\cdot}kg^{-1}$, but the content of free sugar increased by 19.5%. The content of capsaicin and soluble solid content in OLF-1.3X treatment were significant different with other treatments. The yield of red pepper in OLF-1.0X treatments increased by 15% with $4,190kg{\cdot}10a^{-1}$ compared to control of $3,643kg{\cdot}10a^{-1}$, and OLF-1.3X and OLF-0.7X treatments showed increase by 10% and 6%, respectively.