• Journal of the Korean Society of Safety
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• v.12 no.4
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• pp.214-219
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• 1997

The mechanical seals, which are installed in rotating machines like pump and compressor, are generally used as sealing devices in the many fields of industries. The failure of mechanical seals such as leakage, crack, breakage, fast and severe wear, excessive torque, and squeaking results in big problems. To identify abnormal phenomena on mechanical seals and to propose the proper monitoring parameter for the failure of mechanical seals, sliding wear experiments were conducted. Acoustic emission, torque, and temperature were measured during experiments. Optical microstructure was observed for the wear processing after every 10 minute sliding at rotation speed of 1750 rpm and scanning electron microscopy was also observed. Except for the initial part of every experiment, the variation of acoustic emission was well coincided with torque variation during the experiments. This study concludes that acoustic emission and torque are proper monitoring parameters for the failure of mechanical seals. The intensity of acoustic emission signals is measured in root mean square voltage. Temperature of sealing face will be used as a parallel parameter for increasing the reliability of monitoring system.

• Journal of agriculture & life science
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• v.45 no.6
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• pp.265-278
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• 2011

Effects of the open level of the side window were studied to control the temperature and relative humidity in the fog cooling greenhouse. The greenhouse was cooled by air atomizing spray nozzles of the air and water two-fluid process. The control process includes the measuring of environmental variables, setting and coding of the water balance equations and heat balance in greenhouse, calculating of the roof window open and spray water, and operating of the motor and pump. The target temperature and relative humidity were set at $28^{\circ}C$, 75%, respectively. The three modes of the side window open level were 0%, 50% and 100%. The average dry bulb temperatures of the inside air were 28.2, 27.2 and $26.3^{\circ}C$, respectively and their standard deviation was ranged from $0.4^{\circ}C$to $0.8^{\circ}C$. Also the relative humidity of the 0% mode was the best controlled one with the average of 76.3% and the standard deviation of 2.1%.

• Food Engineering Progress
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• v.22 no.4
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• pp.321-327
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• 2018

The main purposes of this study were to identify the factors affecting the supercooling property and to improve the possibility of supercooling storage of fruits and vegetables. Freezing point and nucleation temperature, moisture content, hardness, sugar content, and pH of nineteen fruits and vegetables were measured and Pearson correlation analysis was performed. Freezing point showed a statistically significant correlation with moisture content and sugar content (p<0.01), while ice nucleation temperature showed a correlation (p<0.05) only for sugar content. In particular, the water content and sugar content did not show any correlation with the freezing supercooling difference (FSD). From the correlation analysis between FSD, aerobic bacteria, lactic acid bacteria, yeast, and mold, FSD showed a correlation (p<0.01) with aerobic bacteria. The experiments of the saline solutions inoculated with aerobic bacteria at different concentrations showed FSDs of about 2 for saline inoculated with 9.4 log CFU/mL and about 6 for saline inoculated lower than 5 log CFU/mL. Therefore, the aerobic bacteria concentration was determined to be a key factor affecting the supercooling storage of fruits and vegetables.

• Science of Emotion and Sensibility
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• v.20 no.3
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• pp.169-180
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• 2017

Individuals with high trait anxiety try to suppress their anger expression, thus there are limits in measuring their anger using subjective behavioral evaluation. In order to overcome this limitation, this study attempted to identify the difference in the autonomic nervous system responses induced by anger in individuals with high trait anxiety. Participants were divided into two groups, anxiety and control groups. Electrocardiogram (ECG), respiration (RESP), electrodermal activity (EDA), and skin temperature (SKT) were measured while participants were presented with an anger-inducing stimulus. Heart rate (HR), standard deviation of NN interval (SDNN), root mean square of successive difference (RMSSD), low frequency (LF), high frequency (HF), LF/HF ratio, respiration rate (RR), skin conductance level (SCL), and maximum skin temperature (maxSKT) were calculated before and after presenting the stimulus. Anxiety group reported greater anger by the anger-inducing stimulus compared to the control group. Anxiety group also showed significant increase in SDNN and LF, and decrease in HF, LF/HF ratio, and RR. These results suggest that the autonomic nervous system responses may be used as objective indicators of anger experiences in individuals with high trait anxiety.

• Applied Biological Chemistry
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• v.48 no.3
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• pp.267-272
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• 2005

trans-Cinnamaldehyde, a major component of Cinnamomum cassia, was quantitatively analyzed using the $^1H-NMR$ spectrometry. Applicability of this method was confirmed through observing the variation of chemical shift in the $^1H-NMR$ spectrum of t-cinnamaldehyde and the integration value according to various sample concentrations or running temperatures. When the $^1H-NMR$ spectrometry was run for t-cinnamaldehyde (7.1429 mg/ml) at 19, 25, 30, 40 and $50^{\circ}C$, the chemical shifts of the doublet methine signal due to an aldehyde group were observed at 9.7202, 9.7184, 9.7169, 9.7142 and 9.7124 ppm, respectively, to imply that the running temperature had no significant variation in the chemical shift of the signal. The integration values of the signal were $1.37\;(19^{\circ}C),\;1.37\;(25^{\circ}C),\;1.37\;(30^{\circ}C),\;1.37(40^{\circ}C)$ and $1.37(50^{\circ}C)$, respectively, to also indicate running temperature gave no effect on the integration value. When the sample solutions with various concentrations such as 0.4464, 0.8929, 1.7857, 3.5714, 7.1429 and 14.286 mg/ml were respectively measured for the $^1H-NMR$ at $25^{\circ}C$, the chemical shifts of the aldehyde group were observed at 9.7206, 9.7201, 9.7196, 9.7192, 9.7185 and 9.7174 ppm. Even though the signal was slightly shifted to the high field in proportion to the increase of sample concentration, the alteration was not significant enough to applicate this method. The calibration curve for integration values of the doublet methine signal due to the aldehyde group vs the sample concentration was linear and showed very high regression rate ($r^2=1.0000$). Meantime, the $^1H-NMR$ spectra (7.1429 mg/ml $CDCl_3,\;25^{\circ}C$) of t-cinnamaldehyde and t-2-methoxycinnamaldehyde, another constituent of Cinnamomum cassia, showed the chemical shifts of the aldehyde group as ${\delta}_H$ 9.7174 (9.7078, 9.7270) for the former compound and ${\delta}_H$ 9.6936 (9.6839, 9.7032) for the latter one. The difference of the chemical shift between two compounds was big enough to be distinguished using the NMR spectrometer with 0.45 Hz of resolution. The contents of cinnamaldehyde in Cinnamomum cassia, which were respectively extracted with n-hexane, $CHCl_3$, and EtOAc, were determiend as 94.2 \;mg/g (0.94%), 137.6 mg/g (1.38%) and 140.1 mg/g(1.40%) t-cinnamaldehyde in each extract, respectively, by using the above method.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.2
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• pp.201-207
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• 2014

The changes of growth characteristics and antioxidant activity for selection of optimum germinated temperature on common bean (Phaseolus vulgaris L.). Common beans (IT100888, IT102849, and IT231267) were cultivated at $20^{\circ}C$, $23^{\circ}C$ and $25^{\circ}C$ during 5 days of germination. The range of whole length, hypocotyls length, thickness, abnormal germination and yield rate of sprouts was 7.27~27.62 cm, 3.10~18.86 cm, 1.80~2.27 mm, 5.54~18.34% and 205.95~ 618.71%, respectively. Antioxidant activities of common beans with germination temperature investigated. Common beans (IT100888, IT102849, and IT231267) germinated at $20^{\circ}C$, $23^{\circ}C$ and $25^{\circ}C$ during 5 days, and then extracted with 80% ethanol, and analyzed for total polyphenol content, DPPH and ABTS radical scavenging activity. Total polyphenol content increased from 474 mg GA eq/100 g sample for IT231267 to 1364 mg GA eq/g sample for $23^{\circ}C$ of germination. DPPH radical scavenging activity of IT102849 increased from 189mg Trolox eq./100 g sample ($20^{\circ}C$) to 1073mg Trolox eq./100 g sample ($23^{\circ}C$) also ABTS radical scavenging activity of IT234267 increased from 479 mg Trolox eq./100 g sample ($20^{\circ}C$) to 1134 mg AA eq/100 g ($23^{\circ}C$). These results suggest that germination temperature for increasing antioxidant activities may be $23^{\circ}C$.

• Science of Emotion and Sensibility
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• v.7 no.3
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• pp.51-56
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• 2004

Arousal level has been well defined by autonomic responses. However, entire emotion including both valence and arousal level is often questioned to be completely described by only autonomic responses. This study is to find the autonomic physiological parameters which were used emotion evaluation, 15 undergraduate students were asked to watch eight video clips from diverse movies and comedy shows for experiencing emotions. The subjectively experienced emotion were grouped by three factors. Two dimensional emotion model having the pleasant-unpleasant and arousal-non arousal factors were mapped with three physiological responses(GSR, PPG, SKT). The results may suggest that PPG and GSR may be used as arousal index while SKT may pleasant index. And the complex relation of physiological responses to emotional experiences are discussed.

• Journal of the Korean Vacuum Society
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• v.15 no.3
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• pp.314-324
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• 2006

The vacuum characteristics of the KSTAR ICRF antenna were experimentally investigated. The fabricated antenna was installed in the RF Test Chamber(RFTC) which has a vacuum system with an effective pumping speed of 1015 l/s. The time variations of RFTC pressure, total gas load and ultimate pressure were measured before the RF test. RF conditioning effect was studied by repeating RF pulses at low power level. A time variation of the RFTC pressure was measured during a RF power was applied to the antenna. Threshold pressure at which a RF breakdown occurs was investigated. Whenever the pressure was higher than $10^{-4}$ mbar, the RF breakdown occurred. During a long pulse testing, the temperature of the antenna and RFTC pressure were measured to investigate long pulse limitation of the maximum available voltage without any cooling, which were compared with testing results with a water cooling of the antenna.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.08a
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• pp.92-96
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• 2002

A silver indium sulfide $(AgInS_{2})$ epilayer was grown by the hot wall epitaxy method, which has not been reported in the literature. The grown $AgInS_{2}$ epilayer has found to be a chalcopyrite structure and evaluated to be high quality crystal. From the photocurrent measurement in the temperature range from 30 K to 300 K, the two peaks of A and B were only observed, whereas the three peaks of A, B, and C were seen in the PC spectrum of 10 K. These peaks are ascribed to the band-ta-band transition. The valence band splitting of $AgInS_{2}$ was investigated by means of the photocurrent measurement. The crystal field splitting, $\Delta_{cr}$, and the spin orbit splitting, $\Delta_{so.}$ have been obtained to be 0.150 eV and 0.009 eV at 10 K, respectively. And, the energy band gap at room temperature has been determined to be 1.868 eV. Also, the temperature dependence of the energy band gap, $E_{g}(T)$, was determined.

• Journal of the Korean Vacuum Society
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• v.11 no.1
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• pp.68-75
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• 2002

It is observed the characteristic of the microwave air plasma in the wide range of the operating pressure, 1 mTorr ~ 760 Torr. The microwave air plasma was generated by an AC-type microwave source manufactured with a magnetron taken from a commertial microwave oven and the input power was fixed at 370 W. Characteristics of the plasmas were observed by an injection Langmuir probe and an OES(Optical Emission Spectroscopy). The breakdown electric field is drastically changed at 500 mTorr. For < 500 mTorr, the ratio of the breakdown electric field and the pressure decreased inversely to the pressure, $5.7\times10^4$V/m-Torr.However, the ratio increased linearly as 43 V/m-Torr for the operating pressure, > 500 mTorr. The minimum breakdown electric field was observed about 12. kV/m at 500 mTorr. It corresponds that the input frequency equals to the collision frequency. The effective collision cross section of the air at this pressure was calculated as $9.23\times10^{-l6}\textrm{cm}^2$.The results of the OES measurement revealed that the main ions were composed of the oxygen, argon, and nitrogen for > 500 mTorr. In contrast, only oxygen and argon ions were dominated for < 500 mTorr. ion temperature of oxygen (O(II)) in the air was decreased from about 1.2 eV to 0.5 eV as the pressure increased. Langmuir probe data shows that the plasma density for < 500 mTorr was higher that for > 500 mTorr.