• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.3
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• pp.234-238
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• 1990

The effects of salt concentration immersion time in a salt solution prior to air dehydration and heating of air temperature during dehydration upon the browning reaction and pyruvic acid content of air dried garlics to a 6.5% moisture content(wet basis) were analyzed by a response surface methodology(RSM), Those values were also predicted by using a second degree polynomial regression model. Heating of air temperature was the most significant factor affecting the both browning reaction and pyruvic acid content. Salt concentration had more influence to browning reaction than immersion time whereas immersion time was more impor-tant factor than salt concentration on a retention of pyruvic acid sugested different processing conditions. While the processing conditions to minimize the browning reaction(O.D=0.009) were 0.3% of salt solution 9 min of immersion time and 5$0^{\circ}C$ of air temperature compared to control(O.D=0.022) of air dehydration at 5$0^{\circ}C$ Pyruvic acid contents were maximized(174 $\mu$mole/g garlic solid) at the 0.1% of salt solution 3 min of immersion time and 5$0^{\circ}C$ of air temperature compared to control(147 $\mu$mole/g garlic solid) of air dehydration at 5$0^{\circ}C$

• Korean Chemical Engineering Research
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• v.56 no.3
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• pp.416-420
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• 2018

A comprehensive kinetic study has been conducted on dimethyl carbonate synthesis by transesterification reaction of ethylene carbonate with methanol. An alkali base metal (KOH) was used as catalyst in the synthesis of DMC, and its catalytic ability was investigated in terms of kinetics. The experiment was performed in a batch reactor at atmospheric pressure. The reaction orders, the activation energy and the rate constants were determined for both forward and backward reactions. The reaction order for forward and backward reactions was 0.87 and 2.15, and the activation energy was 12.73 and 29.28 kJ/mol, respectively. Using the general factor analysis in the design of experiments, we analyzed the main effects and interactions according to the MeOH/EC, reaction temperature and KOH concentration. DMC yield with various reaction conditions was presented for all ranges using surface and contour plot. Furthermore, the optimal conditions for DMC yield were determined using response surface method.

• CELLMED
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• v.6 no.2
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• pp.14.1-14.5
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• 2016

Taemyeongcheong (TMC) is Korean traditional extracted drink with various health ingredients. TMC has been used to treat hepatic damage, obesity, gastritis, and colitis. However, the role of TMC on allergic reaction has not been studied yet. In this study, we investigated the anti-allergic effects of TMC against a compound 48/80-induced systemic anaphylactic reaction and IgE-mediated passive cutaneous anaphylaxis (PCA). TMC significantly inhibited the compound 48/80-induced systemic anaphylactic reaction and IgE-mediated PCA reaction. Furthermore, TMC reduced the levels of interleukin (IL)-1β, IL-4, IL-13, and vascular endothelial growth factor in the serum of mice under PCA reaction. Taken together, these results suggest that TMC can play a useful role as an anti-allergic agent.

• Journal of the Korean Chemical Society
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• v.13 no.4
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• pp.241-247
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• 1969

The catalytic reaction between carbon monoxide and oxygen was investigated with the various nickel oxide catalysts at different partial pressures of carbon monoxide and oxygen and at reaction temperatures in the region of 120$^{circ}$to 250$^{circ}C$. The reaction has the highest rate with the nickel oxide catalyst which is sintered at low temperature. A reaction mechanism to explain the data is derived. From the Arrhenius equation, the activation energies in the region of experimental temperatures are found to be from 5.49 to 9.15 kcal/mole. The concentration of excess oxygen in the nickel oxide seems to vary according to the sintering temperatures and periods and is the controlling factor in determining the type of kinetics followed by the catalytic reaction.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.19 no.2
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• pp.225-231
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• 2021

The reaction between Li₂CO₃ and Cl₂ was investigated to verify its occurrence during a carbon-anode-based oxide reduction (OR) process. The reaction temperature was identified as a key factor that determines the reaction rate and maximum conversion ratio. It was found that the reaction should be conducted at or above 500℃ to convert more than 90% of the Li₂CO₃ to LiCl. Experiments conducted at various total flow rate (Q) / initial sample weight (W_i) ratios revealed that the reaction rate was controlled by the Cl₂ mass transfer under the experimental conditions adopted in this work. A linear increase in the progress of reaction with an increase in Cl₂ partial pressure (pCl₂) was observed in the pCl₂ region of 2.03-10.1 kPa for a constant Q of 100 mL·min^-1 and W_i of 1.00 g. The results of this study indicate that the reaction between Li₂CO₃ and Cl₂ is fast at 650℃ and the reaction is feasible during the OR process.

• The Journal of the Korea Contents Association
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• v.12 no.6
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• pp.371-379
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• 2012

The purpose of this study is to develop basic data in improving quality of life along with the enhancement in oral health, by arranging a plan for being able to reduce dental fear given the dental treatment in the future by grasping the subjective oral health recognition & status, and the dental fear level of the dental treatment field targeting patients of visiting dental clinics in Busan and Gyeongnam area. In the whole items of DFS, a sense of fear was higher in women than men. A factor of avoiding dental treatment stood at 1.72 points in men and 2.10 points(p<0.001) in women. A factor of response to stimulation stood at 2.75 points in men and 3.20 points(p=0.001) in women. A fear level according to dental kind was high in a factor of avoiding implant treatment(p=0.015), a factor of avoiding orthodontic treatment(p=0.002), physiological reaction(p=0.009), a factor of avoiding prosthesis treatment(p=0.014), a factor of avoiding pulpectomy treatment(p=0.005), a factor of physiological reaction(p=0.017), a factor of avoiding periodontal therapy(p=0.013), a factor of physiological reaction(p=0.004), and a factor of avoiding treatment given not receiving regular checkup(p=0.027). In the above results, to reduce dental fear, there will be a need of developing diverse programs and oral health eduction for regular checkup and preventive treatment.

• Journal of the Korean Society of Safety
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• v.27 no.5
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• pp.77-87
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• 2012

Compared to a batch reactor, where all reactants are initially charged to the reactor, the semi-batch reactor presents serious advantages. The feed of at least one of the reactants provides an additional way of controlling the reaction course, which represents a safety factor and increases the constancy of the product quality. The aim of this study was to investigate the characteristics of thermal hazard such as a feed time, catalysis concentration and solvent concentration in methylthioisocyanate(MTI) synthesis reaction process. The experiments were carried out by the Multimax reactor system and Accelerating rate calorimeter(ARC). The MTI synthesis reaction process has many reaction factors and complicated reaction mechanism of multiphase reaction. Through this study, we can use as a tool for assessment of thermal hazard of other reaction processes by applying experiment method provided.

• Journal of the Korean Geotechnical Society
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• v.36 no.11
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• pp.7-20
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• 2020

In this study, the dynamic behavior of a single pile foundation was investigated by using an analytical and numerical studies. The emphasis was given on quantifying a function about the coefficient of dynamic horizontal subgrade reaction from 3D analysis. Based on the numerical analysis, a modified correction factor (α), which is used to obtain the coefficient dynamic horizontal subgrade reaction, was proposed by considering shear wave velocity of soil and confining stress. It was found that the prediction by pseudo-static analysis using the proposed coefficient is in good agreement with the general trends observed by dynamic analysis, and it represents a practical improvement in the prediction of behavior for pile foundations subjected to dynamic loads.

• Journal of Biosystems Engineering
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• v.39 no.1
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• pp.11-20
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• 2014

Purpose: Walking type cultivator used for weeding generated excessive handle vibration as well as bouncing motion depending on the weeding speed. This research was conducted to define a design factor of the rotary weeding blades for reducing soil reaction forces as well as hand vibration. Methods: The motion and forces acting on the rotary blades were reviewed to find out the most influencing parameter on hand vibration. The installation angle (IA) of the blade was selected and analyzed to determine the condition of no reaction force less. For removing the unnecessary upward soil reaction, the design factor theory of weeding blade was suggested based on geometrics and dynamics. For evaluation of design factor theory, the experiment in situ was performed base on ISO 5349:1. The vibration $a_{hv}$ and theoretical value $X_{MF}$ were compared with two groups that one was positive group ($X_{MF}$ > 0) and the other was negative group ($X_{MF}$ < 0). Results: $X_{MF}$ was derived from rotational velocity, forward velocity, disk diameter, weeding depth, blade's width and IA of blade. Two groups had significant difference (p < 0.05). In aspect of the group mean total exposure duration, positive group was 17.53% bigger than negative group. When disk radius 100, 150 and 200 mm, minimum IAs were $4{\sim}27^{\circ}$, $3{\sim}15^{\circ}$ and $2{\sim}10^{\circ}$, respectively. A spread sheet program which calculated XMF was developed by Excel 2013. Conclusions: According to this result, minimum IA of weeding blade for soil reaction reduction could be obtained. For reduction hand-arm vibration and power consumption, minimum IA is needed.

• Applied Microscopy
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• v.44 no.1
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• pp.21-29
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• 2014

Retinal glial responses to hypertensive glaucomatous injury were spatiotemporally surveyed. Retinas as a whole or vertical sections were processed for anti-glial fibrillary acidic protein (GFAP), anti-Iba1, anti-nerve growth factor (NGF), and anti-tumor necrosis factor (TNF)-${\alpha}$ immunohistochemistry for confocal microscopic analyses. The optic nerve head of paired controls was processed for electron microscopy. GFAP positive astrocytes appeared in the nerve fiber layer in the glaucomatous and control retinas, changing from fine protoplasmic to stout fibrous parallel to glaucomatous duration. Iba1 positive microglia appeared in both retinas, and enormous reaction appeared at the latest glaucomatous. M$\ddot{u}$ller reaction detected by GFAP reactivity expanded from the end feet to whole profile following to duration in the glaucomatous. NGF reactivity expended from the end feet to the proximal radial processes of the M$\ddot{u}$ller cells in both retinas according to glaucomatous duration. TNF-${\alpha}$ immunoreactivity in the nerve fiber layer was stronger in both the glaucomatous and controls than in the normal, and exceptionally at the latest glaucomatous was even lower than the normal. The astrocytes in the optic nerve head are interconnected with each other via gap junction. These results demonstrate that astrocyte reaction propagates to the contralateral via physical links, and TNF-${\alpha}$ is correlated with NGF production for neuroprotection in response to hypertensive glaucomatous injury.