• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.2 s.25
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• pp.77-86
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• 2006

Usually, a tracking-gate of the tracker is used to track the target radar signal in the active ECM system. In this paper, we propose the feed-back tracking-gate filtering method. The designed method applies a tracking-gate of the tacker to the ECM system's receiver as a rejection or pass filter selected by the receiver's purpose, and the specific target signals can be passed or rejected though this tracking-gate filter. Thus, the number of input signals within the receiver's search band is minimized owing to this filter except the target signals. In conclusion, the EW equipment's reaction time can be reduced and the error value about the target signals can be lower than the previous methods'.

• Bulletin of the Korean Chemical Society
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• v.11 no.6
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• pp.527-530
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• 1990

The effects of the concentration and the pressure of reactants on laser output were reported in the previous study. The present study is made of the following main parameters on laser characteristics; the initial temperature of the reaction mixture, inert gas (He) added in the reaction mixture, and the level of initiation as a function of time. As the initial temperature of reaction mixture decreases, both the output energy and the duration time increase. Especially, the output energy is linearly proportional to the inverse of the initial temperature. In order to obtain a proper lasing for a given condition, a sufficient amount of He must be added: The optimum ratio of [He] to $[D_2\;+\;F_2\;+\;CO_2]$ is found to be greater than 2. In addition, the time dependence of level of initiation (TDLI) shows no significant difference in total output energy from that of the premixed model, but only the power profile.

• International Journal of Oral Biology
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• v.46 no.3
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• pp.140-145
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• 2021

This study aimed to develop Lautropia mirabilis-specific quantitative real-time polymerase chain reaction (qPCR) primers based on the sequence of DNA-directed RNA polymerase subunit beta gene. The PrimerSelect program was used in designing of the qPCR primers, RTLam-F4 and RTLam-R3. The specificity of the qPCR primers were performed by conventional PCR with 37 strains of 37 oral bacterial species, including L. mirabilis. The sensitivity of the primers was determined by qPCR with the serial dilution of purified genomic DNA of L. mirabilis KCOM 3484, ranged from 4 ng to 4 fg. The data showed that the qPCR primers could detect only L. mirabilis strains and as little as 40 fg of genome DNA of L. mirabilis KCOM 3484. These results indicate that this qPCR primer pair (RTLam-F4/RTLam-R3) may be useful for species-specific detection of L. mirabilis in epidemiological studies of oral bacterial infectious diseases such as periodontal disease.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.2
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• pp.103-110
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• 2019

Cu-Zn-Al catalysts were prepared via co-precipitation method for low-temperature water-gas shift (LT-WGS) reaction under practical reaction condition. Aging time was systematically changed to find optimum point for LT-WGS under practical condition. The Cu-Zn-Al catalyst aged for 72 hours showed the highest CO conversion within low-temperature range as well as very stable catalytic activity for 200 hours despite the practical reaction condition.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1295-1300
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• 2010

The $CO_2-CH_4$ reaction catalyzed by Ni/silicon wafers was kinetically studied by using a photoacoustic technique. The catalytic reaction was performed at various partial pressures of $CO_2$ and $CH_4$ (50 Torr total pressure of $CO_2/CH_4/N_2$) in the temperature range of 500 - $650^{\circ}C$ in a static reactor system. The photoacoustic signal that varied with the $CO_2$ concentration during the catalytic reaction was recorded as a function of time. Under the reaction conditions, the $CO_2$ photoacoustic measurements showed the as-prepared Ni thin film sample to be inactive for the reaction, while the $CO_2/CH_4$ reactions carried out in the presence of the sample pre-treated in $H_2$ at $600^{\circ}C$ were associated with significant time-dependent changes in the $CO_2$ photoacoustic signal. The rate of $CO_2$ disappearance was measured from the $CO_2$ photoacoustic signal data in the early reaction period of 50 - 150 sec to obtain precise kinetic data. The apparent activation energy for $CO_2$ consumption was determined to be 6.9 kcal/mol from the $CO_2$ disappearance rates. The partial reaction orders, determined from the $CO_2$ disappearance rates measured at various $PCO{_2}'S$ and $PCH{_4}'S$ at $600^{\circ}C$, were determined to be 0.33 for $CH_4$ and 0.63 for $CO_2$, respectively. Kinetic data obtained in these measurements were compared with previous works and were discussed to construct a catalytic reaction mechanism for the $CO_2-CH_4$ reaction over Ni/silicon wafer at low pressures.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1045-1052
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• 2003

To develop a burnt beef flavor by reaction flavor technology, hydrolyzed vegetable protein (HVP) was reacted with precursors. Ribose, cysteine, furaneol, thiamin, methionine, garlic powder, and phospholipid were selected as suitable precursors for producing a burnt beef flavor. HVP and the selected precursors were reacted in a high pressure reactor to optimize reaction parameters, such as temperature, time, and water content. Optimum reaction conditions were $130^{\circ}C$, 1 hr, and 7.5% water addition. A burnt beef flavor was generated without pH adjustment. On the basis of an omission test, cysteine, furaneol, thiamin, and garlic powder were evaluated for optimization using response surface methodology. The optimum composition of precursore was determined to be 7.7% cysteine, 7.3% furaneol, 2.1% thiamin, and 6.9% garlic powder. Based on these results, optimum reaction conditions for the production of a burnt beef flavor from HVP were 5% ribose, 5% methionine, 5% phospholipid, 7.7% cysteine, 7.3% furaneol, 2.1% thiamin, 6.9% garlic powder, 7.5% water addition, $130^{\circ}C$ reaction temperature, and 1hr reaction time.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.1
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• pp.89-94
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• 2006

Traditionally fatty acid composition used to be analysed by a GC and the sample preparation process includes lipid extraction from sample and subsequent methyl esters preparation, which are time-consuming and cumbersome. As an alternative, simultaneous extraction/methylation methods are being developed for rapid and simplified sample preparation. To optimize one-step extraction/methylation method for analysis of fatty acid composition in brown rice, various reaction factors such as sample to reaction solution ratio, reaction time and temperature, shaking intensity were changed and resultant fatty acid composition data were evaluated in comparison with previous reports. The ratio of sample weight to reaction solution volume was the most critical factor in that higher sample to reaction solution ratio caused overestimation of palmitic acid and linoleic acid composition, resulting in underestimation of oleic acid. Lower reaction temperature also induced overestimation of linoleic acid and underestimation of oleic acid. Reaction duration and the intensity of shaking prior to and during the reaction, however, caused no significant changes in analysis results. In conclusion, the optimum condition was mixing 5 grains (about 0.2 g) of brown rice with $680{\mu}L$ of extraction/methylation mixture and $400{\mu}L$ of heptane, followed by reaction at $80^{\circ}C$ for 2 hours.

• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.833-841
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• 2021

During the postulated severe accident of nuclear reactor, eutectic reaction leads to low-temperature melting of fuel cladding and early failure of core structure. In order to model eutectic melting with the moving particle semi-implicit (MPS) method, the eutectic reaction model is developed to simulate the eutectic reaction phenomenon. The coupling of mass diffusion and phase diagram is applied to calculate the eutectic reaction with the uniform temperature. A heat transfer formula is proposed based on the phase diagram to handle the heat release or absorption during the process of eutectic reaction, and it can combine with mass diffusion and phase diagram to describe the eutectic reaction with temperature variation. The heat transfer formula is verified by the one-dimensional melting simulations and the predicted interface position agrees well with the theoretical solution. In order to verify the eutectic reaction models, the eutectic reaction of uranium and iron in two semi-infinite domains is simulated, and the profile of solid thickness decrease over time follows the parabolic law. The modified MPS method is applied to calculate Transient Reactor Test Facility (TREAT) experiment, the penetration rate in the simulations are agreeable with the experiment results. In addition, a hypothetical case based on the TREAT experiment is also conducted to validate the eutectic reaction with temperature variation, the results present continuity with the simulations of TREAT experiment. Thus the improved method is proved to be capable of simulating the eutectic reaction in the severe accident.

• Women's Health Nursing
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• v.9 no.3
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• pp.224-234
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• 2003

Purpose: This study was to test the effects of a full body massage on labor pain and delivery stress reaction for primipara during labor. Method: This study employed a quasi- experimental method(nonequivalent control group, pre-post test design). The subjects of this study were 57 primipara hospitalized at the U OB & GYN hospital in Inchon from November 1. 2001 to July 31, 2002. 28 women were assigned to the experimental group and 29 to the control group. The experimental group was given 20 minutes full body massage for each of three delivery phases. The control group was given conventional delivery care. The levels of labor pain were measured by the Visual Analogue Scale and the expression scores of the labor pain and the levels of delivery stress reaction were measured by pulse rate, respiration rate, and blood pressure, and State-Anxiety Scale. Data were analyzed using the repeated measures analysis of covariance(ANCOVA), t-test, $X^2$- test, simple ANCOVA with SPSS program. Result: There was no interaction effect between time and group(F=.370, p=.693), but significant time effects were found for subjective labor pain(F=3.840, p=.028). There was no interaction effect between time and group(F=.112, p=.894), but significant group effects were found for objective labor pain(F=12.299, p=.001). There was no interaction effect between time and group for PR(F=.172, p=.843), RR(F=.626, p=.539), SBP(F=.089, p=.915), DBP(F=.748, p=.479), but significant group effects were found for SBP(F=7.547, p=.008). The level of status anxiety of the experimental group was significantly lower than the control group(F=11.787, p=.001). Conclusion: This study showed that the full body massage has partially positive effect on labor pain and delivery stress reaction. Therefore this study suggested that the full body massage might be used clinically to help primipara during labor.

• Polymer(Korea)
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• v.36 no.3
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• pp.302-308
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• 2012

The objective of this study is to investigate optimum reaction conditions for the grafting of poly($N$-vinyl- 2-pyrrolidone) (PVP) onto the surface of plasma-treated polypropylene film. The plasma treatment conditions were fixed as 200 W rf power, 6 LPM Ar flow rate, 30 sec treatment time, and 5 min exposure time after treatment. For graft copolymerization, we investigated the change of grafting degree with respect to reaction time, reaction temperature and $N$-vinyl-2-pyrrolidone concentration. Maximum grafting degree was obtained at the conditions of 6 h reaction time, $90^{\circ}C$ reaction temperature, and 40% $N$-vinyl-2-pyrrolidone concentration. The introduction of PVP was confirmed by ATR-FTIR, XPS, and SEM analysis.