• Journal of Welding and Joining
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• v.13 no.4
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• pp.55-64
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• 1995

A study was made to examine the effects of postweld heat treatment(PWHT) on the toughness and microstructures in the weld heat affected zone(HAZ) of Cu-bearing HSLA-100 steel. The Gleeble thermal/mechanical simulator was used to simulate the weld HAZ. The details between toughness and PWHT of HAZ were studied by impact test, optical microscopy(O.M.), scanning electron microscopy (SEM), transmission electron microscopy(TEM) and differential scanning calorimetry(DSC). The decrease of HAZ toughness in single thermal cycle comparing to base plate is ascribed to the coarsed-grain formed by heating to 1350.deg.C. The increase of HAZ toughness in double thermal cycle comparine to single thermal cycle is due to the fine ferrite(.alpha.) grain transformed from austenite(.gamma.)formed by heating to .alpha./.gamma. two phase region. Cu precipitated during aging for increasing the strength of base metal is dissolved during single thermal cycle to 1350.deg.C and is precipitated little on cooling and heating during subsequent weld thermal cycle. It precipitates by introducing PWHT. Thus, the decrease of toughness in triple thermal cycle of $T_{p1}$ = 1350.deg.C, $T_{p2}$ = 800.deg.C and $T_{p3}$ = 500.deg.C does not occur owing to the precipitation of Cu. The behaviors of Cu=precipitates in HAZ is similar to that in base plate. PWHT at 550.deg.C shows highest hardness and lowest toughness, whereas PWHT at 650.deg.C shows reasonable toughness, which improves the toughness of as-welded state.state.

• Journal of the Korean Magnetics Society
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• v.3 no.1
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• pp.7-12
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• 1993

The effects of Mn, Cr or Co addItion on the magnetic properties of Fe-Ni Invar alloys were investigated. The composition range of the three additives is up to 5wt%. In the temperature range of room temperature-$250^{\circ}C$, the variation of specific magnetization with the addition of Mn, Cr or Co in the Fe-Ni alloys except for 5wt% Co shows the phenomenon characteristics of the Invar effect, viz., the specific magnetization decreases very abrubtly with the temperature and the dependence of temperature on the specific magnetization is in the mixed form of $T^{3/2}$ and $T^{2}$. In the room temperature, the amount of increase in the specific magnetization, Curie temperature and coercivity is in order of Co > Cr > Mn. In the case of 5wt% Co an anomalous phenomena were observed due to the occurrance of ferromagnetic $\alpha$ phase which reduces the invar effect.

• Korean Journal of Clinical Pharmacy
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• v.25 no.3
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• pp.171-177
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• 2015

Background: Androgenetic alopecia (AGA), one of alopecias, requires continuous treatment in order to prevent or stop it, and patient's compliance is very important. Currently, only two drugs (finasteride, minoxidil) have been approved for AGA by Food and Drug Administration of United States (US FDA). However, another ${\alpha}-2$ reductase inhibitor, dutasteride, is approved by Korea Ministry of Food and Drug Safety (MFDS) through a phase III trial. For treatment, pharmacotherapy of AGA usually combines topical minoxidil 7% with one of oral <${\alpha}-2$ reductase inhibitor. Objectives: We evaluated the comparative efficacy and adverse effect between topical minoxidil 7%/finasteride 1 mg and topical minoxidil 7%/dutasteride 0.5 mg pharmacotherapy for outpatients with AGA. Also we evaluated the relationship between therapeutic effect and regular hospital visit. Method: This study was performed retrospectively based on electronic medical record (EMR) data of total 98 patients (topical minoxidil 7% with dutasteride 0.5 mg ($Avodart^{(R)}$) or finasteride 1 mg ($Alopecia^{(R)}$, $Propecia^{(R)}$) with diagnosis of AGA from department of dermatology at a secondary hospital from January $1^{st}$, to May $31^{st}$, 2014. Results: The efficacy and adverse event of topical minoxidil 7%/dutasteride 0.5 mg (DUTA group) were 100% and 45.7%, and of topical minoxidil 7%/finasteride 1 mg (FINA group) were 92.1% and 33.3%, respectively. The mean onset time of responses and adverse events in the FINA group were 3.86 months and 4.43 months. Those in the DUTA group were 3.97 months and 5.06 months. Conclusion: Both FINA and DUTA group were highly effective, but the DUTA group showed higher efficacy and adverse effects than those in the FINA group. Dutasteride may be another alternative in AGA treatment.

• Journal of the Korean Ceramic Society
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• v.41 no.2
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• pp.118-124
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• 2004

The properties of AlN made by carbothermal reaction depend on the starting materials, quantity of liquid, the liquid-vapor phase reaction, the N$_2$ flow rate, and the reaction temperature. AlN whisker was synthesized by the VLS and VS methods. Solid ${\alpha}$-A1$_2$O$_3$(AES-11) was carbothermally reduced with carbon black in a high-purity N$_2$ atmosphere with AlF$_3$ to cause whisker grown and additional aluminum liquid to increase whisker yield. Aluminum nitride was perfectly formed at reaction temperatures of 1600$^{\circ}C$. At reaction temperature higher than 1600$^{\circ}C$ the aluminum nitride was completely formed, while the composition remains unaffected. Needle-shaped whiskers formed best at 1600$^{\circ}C$ while higher temperatures disrupted whisker formation. Adding 0 to 15 wt% aluminum to the synthesis favorably affects the microstructure for formation of needle-shaped AlN whisker. Additions over 15 wt% degraded formation of AlN whisker.

• Journal of the Korean Ceramic Society
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• v.40 no.6
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• pp.566-571
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• 2003

Hydroxyapatite (HAp)/Polyacrylic Acid(PAA) homogeneous composites of four different composition ratio were preparation by co-precipitation process with synthetic HAp and PAA as a binder. HAP/PAA composites were molding by cold isostatic pressing and were sintering by various condition in air. Crystallinity and structure of sintered HAp/PAA composites were investigated by XRD and FT-IR. Also, the compressive strength and the fracture surface of sintered specimens were measured by UTM and SEM. HAp/PAA composites were showed phase transformation of partially ${\alpha}$, ${\beta}$-tricalcium phosphate at sintering condition of 1200$^{\circ}C$ and 3 h. The pore size and porosity of sintered body were showed the range of 0.2∼3.0 $\mu\textrm{m}$ and 0.49∼13.43%, respectively. The compressive strength of sintered specimens were appeared the range of 36.6∼58.2 MPa. From these results, the sintered HAp/PAA comosites can be accounted for the microporous HAp having a good compressive strength due to homogeneous pore morphology.

• Composites Research
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• v.25 no.6
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• pp.172-177
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• 2012

For the manufacture of low resistance Si-SiC composite, the properties of reaction sintering in the green body of various mixed ${\alpha}$-SiC powder size with the various carbon contents from 0wt% to 20wt% were investigated. The samples preparation was green body by CIP method under this condition, molten silicon infiltration process was conducted to reaction bonded silicon carbide. the results of sintered density, 3-point bending strength and resistance of analysis showed that varied carbon and silicon melt reacted to convert to fine ${\beta}$-SiC particle and the structure was changed to dense material. The amount of fine ${\beta}$-SiC particle was gradually increased as carbon content increase. According to mixed composite, it's mechanical and specific resistivity properties was strongly influenced by carbon content within 10wt% more then carbon content 10wt% was strongly influenced by phase transition.

• The Journal of Korean Medicine
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• v.39 no.1
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• pp.1-12
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• 2018

Objectives: Astragalus membranaceus has been reported to inhibit immune responses, but its effect on hair loss is not clear. In this study, the effect of A. membranaceus extract (AM) on hair regrowth in C57BL/6 mice with natural hair loss in the telogen phase was investigated. Methods: Mice with natural hair loss were topically treated with 1% AM on the dorsal skin for 2 weeks. Dorsal skin samples were stained with hematoxylin and eosin and probed with an anti-mouse CD8a IgG. The mRNA expression levels of tumor necrosis factor $(TNF)-{\alpha}$, interferon $(IFN)-{\gamma}$ and interleukin (IL)-4 were measured by reverse transcription polymerase chain reaction and quantitative real-time polymerase chain reaction. Results: AM treatment induced hair regrowth in hair loss mice, while control mice suffered continued hair loss. Tapering hair shafts and broken hair follicles were decreased as well as CD8+ T lymphocyte infiltration. In addition, the expressions of $TNF-{\alpha}$, $IFN-{\gamma}$ and IL-4 were reduced by AM treatment. Also, AM treatment significantly increased the KGF expressions in Hs68 fibroblast cells. Conclusion: These results suggest that topical application of A. membranaceus may be an alternative therapy for hair loss.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.15-20
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• 2005

The unstructured model was tested to describe mycelial growth, exopolysaccharide formation, and substrate consumption in submerged mycelial culture of Paeeiliomyees tenuipes C240. The Logistic equation for mycelial growth, the Luedeking-Piret equation for exopolysaccharide formation, and Luedeking­Piret-like equations for glucose consumptions were successfully incorporated into the model. The value of the key kinetic constants were: maximum specific growth rate ${\mu}m,\;0.7281\;h^{-1};$ growth­associated constant for exopolysaccharide production $(\alpha),\;0.1743g(g\;cells)^{-1}$; non-growth associated constant for exopolysaccharide production $(\beta),\;0.0019g(g\;cells)^{-1}\;;$ maintenance coefficient $(m_s),\;0.0572g\;(g\;cells)^{-1}$. When compared with batch experimental data, the model successfully provided a reasonable description for each parameter during the entire growth phase. The model showed that the production of exopolysaccharide in P. tenuipes C240 was growth-associated. The model tested in the present study can be applied to the design, scale-up, and control of fermentation process for other kinds of basidiomycetes or ascomycetes.

• Women's Health Nursing
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• v.16 no.1
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• pp.69-77
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• 2010

Purpose: This study aimed to develop a sexual rights awareness scale for female adults and to further examine the differences after educational sessions for sexual rights awareness with female adults. Methods: Convenient sampling was employed to recruit 152 participants. A self administered questionnaire was developed to explore adult females' understanding of sexual rights awareness. In the next phase, education was provided over 3 consecutive sessions to 28 female university students. Factor analysis and Cronbach's alpha were performed in order to test validity and reliability of the educational sessions. The Wilcoxon rank test was used to identify the differences between pretesting of sexual rights awareness knowledge and post testing after educational sessions was provided. Results: After conducting factor analysis, 5 factors explained 63.3% of the total variance, namely: I) sexuality education, II) prejudice & biasaberration, III) sexual satisfaction, IV) safe & equal sexuality, and V) sexual autonomy. A Cronbach's alpha of 17 items was 0.80. After the education sessions, there was a significant increase in sexual rights awareness. Conclusion: The Sexual rights awareness questionnaire is acceptable as a tool for measuring the level of education in studies. Future research should aim at conducting comparison studies of sexual rights awareness between sexes and cultural differences with larger populations which will further help to develop and to strengthen the rigor with in methodologies.

• Journal of the Korean Magnetics Society
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• v.6 no.4
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• pp.211-217
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• 1996

The effects of Al addition to Fe-B-Nb-Cu alloy for improving the high-frequency magnetic properties and the magnetic properties of ultrathin $Fe_{78}Al_{4}Nb_{5}B_{12}Cu_{1}$ nanocrystalline alloy ribbons with the thickness less than $10\;\mu\textrm{m}$ were investigated. It was found that the effective permeability at frequencies over- 100 kHz was very high and the core loss was very low for the composition $Fe_{78}Al_{4}Nb_{5}B_{12}Cu_{1}$ alloy. Moreover, the reduction of the ribbon thickness below $10\;\mu\textrm{m}$ was very effective in improving their permeability and the core loss characteristics up to the MHz frequency range. The values of effective permeability at 1 MHz and core loss at 0.2 T, 1 MHz were 5,000 and 1.4 kW/kg, respectively. It was considered that these results were due to far refined $\alpha-Fe$ phase structure with grain size less than 10 nm and domain structure modification.