• Journal of Fashion Business
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• v.12 no.6
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• pp.11-22
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• 2008

The goal of this study is to provide beauticians with the fundamental material to use effectively heat permanent wave in beauty industry as well as their customer's satisfaction. It carried out an experiment with damaged hair of a woman in her late twenties to investigate the change of physical and morphological characteristics by its water content when performing heat permanent wave. After spreading 0g, 1g, 2g, 3g, and 4g of water on damaged hair respectively, heat permanent wave was treated and the change of hair was observed. The change of physical characteristic was compared through permanent wave form of hair, tensile strength and elongation. The change of morphological characteristic was observed through Scanning Electron Microscope(SEM) and Transmission Electron Microscope(TEM). The result of experiment on the physical specificity revealed that permanent wave form was the most ideal when the water content was 2g, also 3g. Though the materials with much moisture content formed the results were not satisfied. The material with 0g of water content didn't make the wave. In terms of tensile strength and elongation, tensile strength was generally reduced as per the damaged degree of hair. On the contrary, elongation was increased. It observed the changes of morphological characteristic that the damage on hair cuticle was deepen, as its moisture content was decreased, and cuticle's surface was worn away. The observation of fine structure on hair section by transmission electronic microscope also certainly showed the result that damaged hair having experience with chemical treatment had got much damaged to hair cuticle as well as hair cortex. Generally chemical treatment makes hair damaged. Under consideration of this aspect, the ultimate goal of this thesis is to minimize the damage of hair caused by chemical treatment and get the satisfaction on the hair style. According to the result of experiment, the damaged hair whose moisture content was 3g showed the best permanent wave form.

• Journal of Plant Biotechnology
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• v.39 no.3
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• pp.133-139
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• 2012

The influences of ethylene inhibitors ($AgNO_3$ and silver thiosulfate) and cytokinins (BAP and TDZ) on shoot regeneration from cotyledon and hypocotyl explants of B. napus cv. Youngsan were investigated. The presence of $50{\mu}M$ Silver thiosulfate (STS) in shoot regeneration medium formed shoots at 60-68% after 3-4 weeks of culture, which was enhanced by 2-fold compared to that of Silver nitrate ($AgNO_3$). Moreover, cotyledon explants were more regenerative than hypocotyls; shoots from cotyledon explants began to occur 4-5 days earlier than that of hypocotyl explants. TDZ at a concentration of $8-10{\mu}M$ was effective for shoot regeneration, compared with BAP. Consequently, the optimal shoot regeneration response was observed in medium supplemented with $50{\mu}M\;STS+8{\mu}M\;TDZ$. In transmission electron microscopy (TEM) analysis, higher density of silver nanoparticles was shown to be accumulated widely inside the cell wall and plasmodesmata of regenerating leaf cultured in medium supplemented with $AgNO_3$. By contrast, in the cell cultured in medium with STS, fine-grained deposits were partly observed in the surroundings of the cell wall.

• Korean Journal of Veterinary Service
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• v.40 no.3
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• pp.193-200
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• 2017

This study was carried out to investigate the antimicrobial resistance profiles and resistance genes in 62 Escherichia coli isolated from dogs and cats hospitalized at animal hospitals in Daegu. E. coli isolates showed high resistance to nalidixic acid (46.8%) and ampicillin (45.2%). Resistance to the other antimicrobial agents was less than 30%, and no resistant isolates were detected for imipenem and amikacin. Of the 28 ampicillin-resistant isolates, TEM and CTX-M genes were detected in 16 (57.1%) and 11 (39.3%), respectively. The aadA gene was found in 4 (26.7%) of 15 gentamicin-resistant isolates, and strA-strB gene was found in 10 (66.7%) isolates. The sul I and sul II genes were detected in 11 (61.1%) and 14 (77.8%) of 18 trimethoprim/sulfamethoxazole-resistant isolates, and tetB gene in 9 (81.8%) of 11 minocycline-resistant isolates, and cmlA gene in 2 (22.2%) of 8 chloramphenicol-resistant isolates. The qnrB and qnrS genes were found in 3 (10.3%) and 1 (3.4%) of 28 nalidixic acid-resistant isolates, respectively. Whereas, none of the SHV, CMY-2, tetA, dfr Ia and dfr VII, and qnrA genes were found. Our results show a wide variety of resistance genes in E. coli isolates from dogs and cats. This study also represents the first report of qnrB and qnrS gene producing E. coli isolates from dogs in republic of Korea.

• Korean Journal of Veterinary Research
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• v.33 no.3
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• pp.429-442
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• 1993

The cytotoxic effects of S hyodysenteriae strain B 204 on the mucosal surface were studied in surgically prepared ligated colonic loops in two male convenitonal mixed-breed pigs. In each one of four loops was inoculated with either sterile trypticase soy broth(TSB) of Serpulina, filtrate of Serpulina TSB culture. washed Serpulina cells or whole culture of Serpulina. Mucosal tissues were examined by transmission and scanning electron microscopy 24 and 48 hours after inoculation(p.i.). The filtrate did not induce any significant effect on the mucosal surface. The washed cells produced early lesions similar to those caused by the whole culture. These observations suggest that cytotoxins of the culture do not play a significant role in invasion of the epithelium in this experimental infection. The possible role of toxins associated with the organism at the site of interaction with the epithelial cells was not elucidated.

• Journal of Soil and Groundwater Environment
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• v.20 no.3
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• pp.25-33
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• 2015

In this study, Fe₃O₄-ACCS-Ag nanoparticles (NPs) were successfully synthesized using silica extracted from corn cob ash. The synthesized Fe₃O₄-ACCS-Ag NPs were characterized using X-ray diffraction (XRD), scanning electron microscopyenergy dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM) and fourier transform infrared spectroscopy (FTIR). In addition, the potential application of Fe₃O₄-ACCS-Ag NPs as an antibacterial material in water disinfection was investigated using Escherichia coli ATCC 8739 as model bacteria. The antibacterial activity of synthesized composite material showed 99.9% antibacterial effect within 20 min for the tested bacteria. From this experiment, the synthesized Fe₃O₄-ACCS-Ag nanocomposites also hold magnetic properties and could be easily recovered from the water solution for its reuse. The reused nanocomposites presented the decreasing antibacterial efficiencies with the reuse cycle but the composite used three times still killed 90% of bacteria in 20 min.

• Journal of the Mineralogical Society of Korea
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• v.12 no.2
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• pp.55-65
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• 1999

Spotted cordierite occurs as the result of intrusion of Wolaksan Granite of Cretaceous age in the northern part of the Ogcheon Metamorphic Belt, forming a contact metamorphic zoning in accordance with the distance from the granite body: a cordierite-muscovite-biotite-quartz assemblage and the higher-temperature cordierite-biotite-quartz-(cummingtonite). These quartz-ubiquitous mineral assemblages identified in the cordierite spot seem to reflect Al-deficient condition of the protolith. TEM observations of textural relations between the cordierite and mica within the cordierite spot clearly reflect that cordierite was formed at the expense of micaceous matrix. A structure refinement of the poikiloblastic cordierite was performed by the Rietveld refinement method. Unit cell of the cordierite was determined to be as follows : lower-temperature type: a=17.1480(9)${\AA}$, b=9.7743(6)${\AA}$, c=9.3184(5)${\AA}$, V=1561.9(4)${\AA}$3, higher-temperature type: a=17.136(2)${\AA}$, b=9.751(1)${\AA}$, c=9.322(1)${\AA}$, V=1557.7(4)${\AA}$3. They show a remarkable difference in the unit cell dimension. The refinement results indicate that structural sites of lower-temperature cordierite are wholly occupied by appropriating ions. Compared to this, tetrahedral sites of the higher-temperature type exhibit an order/disorder ranging about 5-8% as the result of substitution between Si4+ and Al3+, except for T26 site occupied wholly by Al3+. These structural differences seem to be related to the formation temperatures of both cordierite types.

• Korean Journal of Materials Research
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• v.5 no.8
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• pp.936-944
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• 1995

The effects of Spinodal decomposition induced phase separated microstructure of InGaAsP/InP heterostructure on photoluminescence(PL) intensity and FWHM(full-width at half maximum) were investigated in this study. Lattice mismatches were measured by double crystal x-ray diffractometer, and the microstructures of phase separated InGaAsP were observed by transmission electron microscopy. It was found that the misfit stress calculated from lattice mismatch was related to the periodicity of Spinodal modulation. Strong dependence of PL intensity and FWHM on the modulation periodicity was also found. For systematic understanding of these observations, the interaction elastic strain energy function induced by misfit stress was proposed. The calculation illustrated that the microstructure of the epilayer such as Spinodal decomposition played an important role in determining the optoelectronic properties such as PL intensity and PL FWHM.

• Korean Journal of Materials Research
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• v.6 no.7
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• pp.692-699
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• 1996

nptype Si(100)웨이퍼를 precleaning하고 HF 용액에 dip etching한 후 E-beam dvaporator에 장착하여 Co 단일막($170\AA$, $340\AA$)과 Co/Ti 이중막($200\AA$/ $(50-100)\AA$)을 성장시켰다. 시편의 RTA 과정에서는 N2분위기에서 direct annealing 방식으로 열처리 온도와 시간을 변화시켜가며 Co-silicidation 공정을 수행하였다. Co 단일막으로 형성된 Co-실리사이드의 면저항은 $500^{\circ}C\leq$T$\leq$$850^{\circ}C$범위에서 열처리 온도와 시간의 변화에 관계없이 거의 일정한 값을 나타내었다. Co/Ti 이중막의 경우 Co-실리사이드의 형성온도가 Co 단일막의 경우에 비해 높게 나타나고 낮은 비저항의 CoSi2를 얻기 위해서는 $800^{\circ}C$이상의 온도로 열처리해야 함을 알 수 있었다. XRD 분석결과, Co 단일막으로부터 얻어진 CoSi2는 (111) 및 (220) 결정상을 나타내었으나, Co/Ti 이중막에 의한 CoSi2는 (200)결정상만이 나타나서 Si(100)기판과 에피층을 이루고 있음을 알 수 있었다. 본 실험에서 CoSi2의 비저항은 약 $18\mu$$\Omega$.cm로 나타났으며, TEM 및 AES 분석으로부터 Co/Ti bilayer-실리사이드가 다량의 Si과 Ti 외에 소량의 Co가 섞여있는 표면 복합층과, Si과 Co만이 존재하는 내부 에피층으로 구성됨을 확인하였다.

• Korean Journal of Materials Research
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• v.25 no.4
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• pp.202-208
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• 2015

Alumina dispersion strengthening copper(ADSC) alloy has great potential for use in many industrial applications such as contact supports, frictional break parts, electrode materials for lead wires, and spot welding with relatively high strength and good conductivity. In this study, we investigated the oxidation behavior of ADSC alloys. These alloys were fabricated in forms of plate and round type samples by surface oxidation reaction using Cu-0.8Al, Cu-0.4Al-0.4Ti, and Cu-0.6Al-0.4Ti(wt%) alloys. The alloys were oxidized at $980^{\circ}C$ for 1 h, 2 h, and 4 h in ambient atmosphere. The microstructure was observed with an optical microscope(OM) and a scanning electron microscope(SEM) equipped with energy-dispersive X-ray spectroscopy(EDS). Characterization of alumina was carried out using a 200 kV field-emission transmission electron microscope(TEM). As a result, various oxides including Ti were formed in the oxidation layer, in addition to ${\gamma}$-alumina. The thickness of the oxidation layer increased with Ti addition to the Cu-Al alloy and with the oxidation time. The corrected diffusion equation for the plate and round type samples showed different oxidation layer thickness under the same conditions. Diffusion length of the round type specimen had a value higher than that of its plate counterpart because the oxygen concentration per unit area of the round type specimen was higher than that of the plate type specimen at the same diffusion depth.

• Korean Journal of Materials Research
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• v.22 no.8
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• pp.403-408
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• 2012

A sample of ultra low carbon IF steel was processed by six-layer stack accumulative roll-bonding (ARB) and annealed. The ARB was conducted at ambient temperature after deforming the as-received material to a thickness of 0.5 mm by 50% cold rolling. The ARB was performed for a six-layer stacked, i.e. a 3 mm thick sheet, up to 3 cycles (an equivalent strain of ~7.0). In each ARB cycle, the stacked sheets were, first, deformed to 1.5 mm thickness by 50% rolling and then reduced to 0.5 mm thickness, as the starting thickness, by multi-pass rolling without lubrication. The specimen after 3 cycles was then annealed for 0.5 h at various temperatures ranging from 673 to 973 K. The microstructural evolution with the annealing temperature for the 3-cycle ARB processed IF steel was investigated in detail by transmission electron microscopy observation. The ARB processed IF steel exhibited mainly a dislocation cell lamella structure with relatively high dislocation density in which the subgrains were partially observed. The selected area diffraction (SAD) patterns suggested that the misorientation between neighboring cells or subgrains was very small. The thickness of the grains increased in a gradual way up to 873 K, but above 898 K it increased drastically. As a result, the grains came to have an equiaxed morphology at 898 K, in which the width and the thickness of the grains were almost identical. The grain growth occurred actively at temperatures above 923 K.