• Journal of the Korean institute of surface engineering
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• v.27 no.3
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• pp.143-148
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• 1994

Effects of process variables of HCD ion plating on the film composition of Ti(C, N) were analyzed. The mole ratio of carbon to nitrogen and that of non-metal to titanium in the film primarily depend on the partial pressure ratio of ($C-2H_2$/ $N_2$) and total reactive gas pressure, respectively. The amount of nonmetallic com-ponents increases in nonlinear fashion as the total gas pressure due to the different reactivity of $C-2H_2$ and $N_2$ gases with Ti. The nonmetallic components was saturated dwith nitrogen when the nitrogen gas was more than 60% of total reactive gas. These two process variables could be related systematically using the concept of effective pressure in which the difference of reactivity of each gas was normalized.

• Journal of the Korean Ceramic Society
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• v.33 no.1
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• pp.41-48
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• 1996

Self-propagating High-temperature Synthesis of Ti+N system has been investigated using the cylindrical high pressure reactor. The nitrogen pressure was varied from 40 to 80 atmosphere and TiNx(x=0.55) powder produced by SHS process was used as a diluent in order to control the reaction. Both the velocity of surface reaction and the ratio of TiN synthesis increased with increasing the nitrogen pressure. As the amount of diluent increases the degree of conversion to titanium nitride increases. Homogenious TiN powder was obtained in the composition 50Ti+50TiN0.94(diluent)

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.263-266
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• 2003

The fine $YBa_2Cu_3O_x$ powder ($0.2{\sim}1.0\;{\mu}m$) is produced by sol-gel method, and electrophoresis deposition is used for the preparation of $YBa_2Cu_3O_x$ thick films which are deposited on Ag wire. The oriented $YBa_2Cu_3O_x$ was tried to be prepared by the zone-melting method under low oxygen partial pressure. The orientation and the phase composition were examined by the X-ray diffraction and the superconductivities were measured by 4 line method. The critical current densities are still quite low, which may be due to unsuitable technical parameters for zone-melting of $YBa_2Cu_3O_x$ thick films. Therefore the heat treatment condition and controlling of low oxygen partial pressure should be improved in the future experiment.

• Korean Journal of Materials Research
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• v.17 no.6
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• pp.308-312
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• 2007

Chromium oxide thin films have been deposited on silicon substrates using a tabletop 9kJ mathertyped plasma focus (PF) device. Before deposition, pinch behavior with gas pressure was observed. Strength of pinches was increased with increasing working pressure. Deposition was performed at room temperature as a function of working pressure between 50 and 1000 mTorr. Composition and surface morphology of the films were analyzed by Auger Electron Spectroscopy and Scanning Electron Microscope, respectively. Growth rates of the films were decreased with pressure. The oxide films were polycrystalline containing some impurities, Cu, Fe, C and revealed finer grain structure at lower pressure.

• Journal of the Semiconductor & Display Technology
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• v.9 no.4
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• pp.77-81
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• 2010

The AZO thin films were deposited on the corning 1737 glass plate by the RF magnetron sputtering and effects of working pressure and oxygen contents on the electrical properties were investigated. XRD spectra showed a preferred orientation along the c-axis and a minimum FWHM for the 70mTorr. From the surface analysis (AFM), the number of crystal grain of AZO thin film increased as working pressure increased. The film deposited with 70mTorr of working pressure showed n-type semiconductor characteristic having suitable resistivity $-1.59{\times}10^{-2}{\Omega}cm$, carrier concentration $-10.1{\times}10^{19}cm^{-3}$, and mobility $-4.35cm^2V^{-1}s^{-1}$ while other films by 7 mTorr, 20 mTorr of working pressure closed to metallic films. The films including the oxygen represent stoichiometric composition similar to the oxide. The transmittance of the film was over 85% in the visible light range regardless of the changes in working pressure and oxygen contents.

• Journal of Sensor Science and Technology
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• v.33 no.1
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• pp.7-11
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• 2024

Soft-pressure sensors have numerous applications in soft robotics, biomedical devices, and wearable smart devices. Herein, we present a highly sensitive electronic skin device with an isotropic wrinkled pressure sensor. A conductive ink for soft pressure sensors is produced by a solution process using polydimethylsiloxane (PDMS), poly 3-hexylthiophene (P3HT), carbon black, and chloroform as the solvents. P3HT provides high reproducibility and conductivity by improving the ink dispersibility. The conductivity of the ink is optimized by adjusting the composition of the carbon black and PDMS. Soft lithography is used to fabricate a conductive elastic structure with an isotropic wrinkled structure. Two conductive elastic structures with an isotropic wrinkle structure is stacked to develop a pressure sensor, and it is confirmed that the isotropic wrinkle structure is more sensitive to pressure than when two elastic structures with an anisotropic wrinkle structure are overlapped. Specifically, the pressure sensor fabricated with an isotropic wrinkled structure can detect extremely low pressures (1.25 Pa). Additionally, the sensor has a high sensitivity of 15.547 kpa^-1 from 1.25 to 2500 Pa and a linear sensitivity of 5.15 kPa^-1 from 2500 Pa to 25 kPa.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.827-832
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• 2012

This study was conducted to develop HTHP ginseng (high temperature and high pressure ginseng) with improved antioxidative activity and phenolic acid composition by high temperature and high pressure process. The HTHP ginseng extract was analyzed for the total phenol content, DPPH radical scavenging activity and phenolic acid composition. The total phenol content was increased in HTHP ginseng (14.76 mg/g) compared to raw ginseng (3.59 mg/g) and red ginseng (3.93 mg/g). DPPH radical scavenging activities of HTHP ginseng, raw ginseng and red ginseng extracts were 4.8~78.4%, 1~47.4% and 1.8~56.5% at $1{\sim}100mg/m{\ell}$ concentration. Also ABTS radical scavenging activities of HTHP ginseng, raw ginseng and red ginseng extracts were 8.9~99.8%, 3.4~96% and 1.2~96.5% at $1{\sim}100mg/m{\ell}$ concentration. In HPLC analysis, amounts of measured phenolic acid of HTHP ginseng greatly increased than raw ginseng and red ginseng, but salicylic acid was not detected in HTHP ginseng. In addition, DPPH radical scavenging activity of phenolic acid from HTHP ginseng was increased. Consequently, we believe high temperature and high pressure process is better method than existing method to increase the bioactivity of ginseng.

• Journal of Korean Medicine Rehabilitation
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• v.25 no.4
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• pp.123-137
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• 2015

Objectives The aim of this clinical study was to find out the changes of vital sign, body composition, skin status before and after combined spa-exercise therapy in participants of middle-aged women. Methods In this study 24 participants of middle-aged women went through 12 weeks of combined spa-exercise therapy. Each week vital sign, body composition, skin status were measured before exercise, which consisted of warming-up, whole body exercise and final exercises bathing in spa ($32{\sim}36^{\circ}C$). Results 1. The average of systolic blood pressure significantly decreased from $126.38{\pm}19.33mmHg$ to $120.46{\pm}11.18mmHg$ after 11 weeks of spa-exercise therapy (p<0.05). 2. The average of moisture of skin significantly increased from $36.83{\pm}3.18$ to $44.21{\pm}7.43$ after 11 weeks of spa-exercise therapy (p<0.05). 3. The average of elasticity of skin significantly increased from $59.75{\pm}3.50$ to $62.63{\pm}2.29$ after 11 weeks of spa-exercise therapy (p<0.05). 4. The average of diastolic blood pressure, pulse, et cetera. didn't significantly change after spa-exercise therapy. Conclusions The results showed that 12 weeks of spa-exercise therapy had significant effect on reducing systolic blood pressure, increasing moisture, elasticity of skin in participants of middle-aged women, which means spa-exercise therapy may be used as a treatment on high blood pressure and cutaneous diseases. Further studies are anticipated to find out other various effects of spa-exercise therapy.

• Journal of the Korean Applied Science and Technology
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• v.39 no.6
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• pp.906-915
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• 2022

The purpose of this study was to investigate the effects of aquatic walking exercise on body composition, hs-CRP, HOMA-IR, and blood pressure in obese elderly women. Twenty, obese elderly women[percent body fat(%BF) < 30%] composed of aquatic walking exercise group(EX, n=10), the control group(CON, n=10). The variables of body composition, hs-CRP, HOMA-IR, and blood pressure were measured in all the subjects pre and post of 12 weeks aquatic walking exercise(RPE 11-14, 3 times per week, 50 mins). The test data were analyzed by paired t-test and repeated ANOVA, and the alpha level of p<.05 was set for all tests of significance. %BF (p<.05), insulin (p<.01), HOMA-IR (p<.01) and SBP (p<.05) were significantly decreased in EX group compared to CON group. These results suggest that 12 weeks of aquatic walking exercise improves %BF, HOMA-IR, and blood pressure. Thus, this proposed aquatic walking exercise modality can be a useful therapy to improve both obese and cardiovascular disease in obese elderly women.

• Journal of the Korean Society of Combustion
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• v.7 no.1
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• pp.15-22
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• 2002

Flame spread experiments of a fuel droplet array were performed using a microgravity environment. N-decane, 1-octadecene, and the blends (50% : 50% vol.) of these fuels were used and the experiments were conducted at pressures up to 5.0 MPa, which are over the critical pressure of these fuels. Observations of the flame spread phenomenon were conducted for OH radical emission images recorded using a high-speed video camera. The flame spread rates were calculated based on the time history of the spreading forehead of the OH emission images. The flame spread rate of the n-decane droplet-array decreased with pressure and had its minimum at a pressure around half of the critical pressure and then increased again with pressure. It had its maximum at a pressure over the critical pressure and then decreased gradually. The pressure dependence of flame spread rate of 1-octadecene were similar to those of n-decan, but the magnitude of the spread rate was much smaller than that of n-decane. The variation of the flame spread for the blended fuel was similar to that of n-decane in the pressure range from atmospheric pressure to near the critical pressure of the blended fuel. When the pressure increased further, it approached to that of 1-octadecene. Numerically estimated gas-liquid equilibrium states proved that almost all the fuel gas which evaporated from the droplet at ordinary pressure consisted of n-decane whereas near and over the critical pressure, the composition of the fuel gas was almost the same as that of the liquid phase, so that the effects of 1-octadecene on the flame spread rate was significant.