• 전기학회논문지
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• 제68권1호
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• pp.61-68
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• 2019

Only the power is converted from AC to DC, in accordance with IEC 60587 based test method, in order to develop the LSR(Liquid Silicone Rubber) insulator material for HVDC, the experiment of Inclined Plate Tracking and Erosion Resistance was conducted. A contaminant (2.5 mS/cm: ammonium chloride) was applied at a rate of 0.3 ml/min and a voltage of ${\pm}3.5kV$, and was evaluated on the basis of 60 mA/2s. The samples were prepared by dispersing LSR/Nano silica_25wt% Composites in LSR. The erosion phenomena of surface discharge and tracking due to DC polarity and negative polarity were measured by image, leakage current maximum and thermal camera. The thermal imaging camera measured the surface temperature generated by the joule heat of the leakage current due to the drying discharge and the conductive current. After the measurement, the tracking and erosion mechanisms were evaluated for erosion weight, erosion depth and erosion length. Positive and negative polarity of LSR/Nano Silica_25wt% composite Tracking and erosion results show that positive polarity is more severe than negative polarity.

• 한국염색가공학회지
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• 제30권4호
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• pp.237-244
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• 2018

Three super hydrophobic red fluorescence dyes were selected to dye high molecular weight polyethylene fiber. Their absorbance and emission spectra were obtained and Stokes' shift was measured. Fluorescence emission strength of the dyes on the fiber was investigated and therefore Fluoro Red 3 was determined as the best one among those three dyes in this experiment. Dyeing properties and fluorescence intensities were investigated using the Fluoro Red 3 on high molecular weight polyethylene fiber at various dyeing conditions. The optimum concentration of a dispersing agent was appeared at 10wt% in aqueous solution. The best dyeing was obtained at $125^{\circ}C$ for 1 hour. The color fastnesses to the washing and rubbing were as high as ratings 4~5, however, the fastness to light was exhibited ratings 2~3.

• Metals and materials international
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• 제24권6호
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• pp.1403-1411
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• 2018

Graphene (multilayer graphene) was chosen as an additive to improve the hydrogen uptake and release properties of magnesium (Mg). Five weight percent of graphene was added to pre-milled Mg by milling in hydrogen (reaction-involving milling). The hydrogen uptake and release properties of the graphene-added Mg were investigated. The activation of Mg-5graphene, which was prepared by adding 5 wt% graphene to Mg pre-milled for 24 h, was completed after the second cycle (cycle number, CN=2). Mg-5graphene had a high effective hydrogen-storage capacity (the quantity of hydrogen absorbed for 60 min) of 6.21 wt% at CN=3 at 593 K in 12 bar $H_2$. At CN=1, Mg-5graphene released 0.46 wt% hydrogen for 10 min and 4.99 wt% hydrogen for 60 min. Milling in hydrogen is believed to create defects (leading to facilitation of nucleation), produce cracks and clean surfaces (leading to increase in reactivity), and decrease particle size (leading to diminution of diffusion distances or increasing the flux of diffusing hydrogen atoms). The added graphene is believed to have helped the sample have higher hydrogen uptake and release rates, weakly but partly, by dispersing heat rapidly.

• The Journal of Korean Physical Therapy
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• 제31권1호
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• pp.31-34
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• 2019

Purpose: This study examined the effects of the fascial distortion model (FDM) method on Cobb's angle. Methods: Fourteen subjects participated in this study. The idiopathic scoliosis group performed FDM treatments eight times in four weeks. A Shapiro-Wilks test was used to verify the normality of a group of idiopathic scoliosis patients. A paired t-test was performed to determine the satisfaction with the normality. Results: The difference in Cobb's angle was reduced significantly (p<0.05) by an average of $5.72^{\circ}{\pm}2.24$ from $15.51^{\circ}{\pm}1.81$ before the experiment. Conclusion: This study found that the use of the FDM method was effective in improving the Cobb's angle. The application of a FDM treatment appears to stabilize the fascia with decreased ability to adapt physiologically. The application of the CD and TB method of FDM treatment improved the asymmetry spine by dispersing moisture in fascia and improving the contraction and relaxation ability. The results suggest that the Cobb's angle is reduced when FDM is applied, thereby preventing the progression of curvature and avoiding psychological and physical problems that can arise from improving patients with scoliosis.

• 한국분말재료학회지
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• 제28권5호
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• pp.381-388
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• 2021

Zirconia has excellent mechanical properties, such as high fracture toughness, wear resistance, and flexural strength, which make it a candidate for application in bead mills as milling media as well as a variety of components. In addition, enhanced mechanical properties can be attained by adding oxide or non-oxide dispersing particles to zirconia ceramics. In this study, the densification and mechanical properties of YSZ-TiC ceramic composites with different TiC contents and sintering temperatures are investigated. YSZ - x vol.% TiC (x=10, 20, 30) system is selected as compositions of interest. The mixed powders are sintered using hot pressing (HP) at different temperatures of 1300, 1400, and 1500℃. The densification behavior and mechanical properties of sintered ceramics, such as hardness and fracture toughness, are examined.

• 대한건축학회논문집:구조계
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• 제34권6호
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• pp.29-34
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• 2018

In this research, regarding the cement supplied to ready mixed concrete plant, the feasibility of rapid acquisition test for cement fineness using hydrometer which used for early strength evaluation of concrete was analyzed. Additionally, regarding the rapid test with hydrometer control factors were provided. As a result of analysis, quality control using hydrometer was possible with the regressive equation obtained in five minute between density of suspension and fineness of cement powder. As the control factors, dispersing admixture, replacing kerosene as a medium, and temperature of cement and water were evaluated. According to the control factor evaluation, the tap water was optimum as a medium and calibration of keeping the temperature of water to $20^{\circ}C$ or correction factor was needed for density results. Finally, it is considered that the suggested rapid quality evaluation method using hydrometer is cheaper and easier method than currently used Blaine test.

• 영어영문학
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• 제64권3호
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• pp.483-530
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• 2018

Unpacking and dispersing rights of various kinds formerly enjoyed by a selected few has been the constant motivation behind the democratization and modernization of human society. Human rights and later civil rights have continuously been constituted and reconstituted in response to the demands of the laboring class, slaves, women, subalterns, animals, and things, expanding beyond the boundaries of class, race, nation, sexuality, gender, species and organism. Calling attention to the ways in which literary and cultural texts have narrated rights so as to inscribe these human, nonhuman, and inhuman demands. Narrating rights offer opportunities to interrogate the lasting contributions of English language and literature to questioning, reforming, and practicing rights. The interrogation is particularly pertinent in this age in which revised and dispersed rights are creating new conflicts, requiring them to be narrated differently and imaginatively so as to allow all the parties in conflict to participate in working out the conflicts. With the 2017 theme of "Literature and Human Rights," JELL editorial collective hope to explore the relationship between literature and human rights in its multiple simultaneous, and plural manifestations in an open platform. "Narrating Rights" is a double-edged task that, on one hand, reflects the singular life conditions or contexts of a human, inhuman or nonhuman being and, on the other hand, aspires to the perpetual process of rights' universal application. Eleven out of all the keynote speakers at the 2017 ELLAK Convention were invited to this roundtable on Literature and Human Rights. The following transcription includes the dialogues of the eleven discussants.

• 공업화학
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• 제32권3호
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• pp.348-356
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• 2021

The lignocellulose-based dried watermelon rind (WR) was modified with sulfuric acid, namely SWR for enhancement of methylene blue (MB) adsorption from the aqueous solution. According to FT-IR analysis, after the modification of WR with sulfuric acid, the functional groups of R-SO₃H, COOH and -OH groups was formated or enhanced on the surface of the WR. Moreover, the point of zero charge (pHpzc) was changed from 6.3 to 4.1 after modification, which widened the range for adsorbing of cationic dye MB. The adsorption process of MB onto the SWR was suitable for pseudo-2nd-order and Langmuir model and the maximum adsorption capacity of Langmuir was found to be 334.45 mg/g at pH 7. In adition, the adsorption process occurs through the electrostatic interaction, hydrogen bridge formation, electron donor-acceptor relationship, and 𝜋-𝜋 electron dispersing force between functional groups on the carbon surface with MB molecules. Depending on functional groups available on the SWR surface, the MB adsorption mechanism can occur in combination with various interactions.

• 대한건축학회연합논문집
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• 제21권3호
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• pp.109-116
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• 2019

This study aimed to suggest a quantitative model analyzing overcrowding area under emergency evacuation situation in the outpatient department of hospital. Overall study process included the review on legal conditions of an emergency evacuation, the investigation of precedent research documents and the analysis of spatial configuration. The user movement with considering exit gates and the one without considering exit gates were analyzed for routine activity condition. An agent-based simulation was applied for the analysis. Also, user movement for the emergency condition was tested with evacuation simulation. The variation of simulation conditions revealed the difference between overcrowding spaces from situation change. At all nodes, visit frequencies derived from different conditions and situations were compared. The overcrowding spaces are to increase the risk of delaying emergency evacuation time which is critical for user safety. It suggests the need for dispersing overcrowding spaces under evacuation situation. The suggested analysis model can evaluate overcrowding spaces in the outpatient department of hospital and provide locational data for distributing evacuation design resources.

• 한국기계가공학회지
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• 제20권11호
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• pp.24-29
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• 2021

In this study, the electrical and mechanical properties of carbon polymer composites, which have been gradually increasing in use in various fields, were investigated, and environment-friendly carbon nanofiber/waterborne polyurethane composites were prepared. Carbon nanofibers (diameter = approximately 100-300 mm) were synthesized using a relatively simple CVD process, obtaining a carbon material for application in ultrathin planar heating films and EMP shielding films in the future. The carbon nanofiber was dispersed, and mixed with water-dispersible polyurethane using a dispersing aid. According to the carbon nanofiber mass ratio, 20%-60% polyurethane/carbon nanofiber composites were manufactured. At a concentration of approximately 20%, the percolation threshold was determined, and at a concentration of approximately 50%, an electrical conductivity greater than 0.1 S/cm was determined. Moreover, a sample having a concentration of up to 60% was evaluated to further understand the mechanical properties. It was observed that as the concentration of the carbon nanofibers increased, the elongation decreased.