• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.81-87
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• 1991

To examine the effect of the individual operational variables on extrusion process, test trials of the fractional factorial design of the three process variables at three levels, including feed rate, screw speed and die openings, were carried out by using a laboratory scale twin-screw extruder with three different screw configuration for corn grit with the water addition fixed at 15% of the powder feed rate. As the increase of feed rate, while extrusion temperature(ET), specific mechanical energy input (SME), and residence time(RT) were showed the tendency to decrease, extrusion pressure(EP) was increased and as the increase of screw speed, ET, SME and EP were showed the tendency to increase, but RT was decreased. However, as increase the number of die hole, all system parameters were showed the tendency to decrease. The influence of the change in each process parameters was increased as the increase of the number of reverse element in screw configuration. In case of using the screw configuration with increasing number of reverse element at the condition of same process parameters, ET, SME and RT was increased, but EP was decreased. The functional relationships of the system parameters to the process parameters can be quantified by using multiple regression equations(mostly R-sq>0.90) and maped on suface response diagrams to expedite evaluation.

• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.325-329
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• 2008

This study was conducted to compare the postharvest physiological characteristics of 2 paprika cultivars; 'Special', 'Fiesta' grown in 2 regions: Chuncheon(plain region) and Hwacheon(semi-high land region), and by 2 cultural methods; soil and hydroponic(rock wool culture). Respiratory rate of paprika fruit was higher in soil culture, and ethylene production was higher in Chuncheon region of both cultivars. As the thickness of fruit flesh showed thicker in Hwacheon region and hydroponic culture, the firmness of fruit was in proportion to thickness. Vitamin C content was higher in red-cultivar, 'Special'. and in Chuncheon region. Soluble solids was higher in 'Special', but there was no different between cultural regions. The fruit of both cultivars was grown smaller in Chuncheon region, and the fruit shape of 'Fiesta' progressed faster in soil culture. The surface color of fruit was higher in Hwacheon, and although there was no significantly different between cultural method, both cultivars grown by hydroponics was shown vivid color. As above results, for the long term circulation and high quality of fruit, paprika may be cultivated by hydroponics in high-altitude region.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.3
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• pp.565-573
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• 2000

Sewer pipe in Korea is generally constructed with concrete pipes. Moreover, the sewer system is susceptible to the corrosion problem due to the regulation employing anaerobic treatment processes, such as domestic sewage treatment facilities, nightsoil septic tanks and so on. The objective of this study is investigated to experimental test of $H_2S$ production rate affecting corrosion of sewer pipe in Korea. In this study, tube-type and sealed-type reactor were used to examine the reactions in the microorganism suspended growth and biofilm. Furthermore. concentration changes were investigated with COD and sulfate reduction in each reactor. Sulfide production rate was $50.4mg-H_2S/g-VSS{\cdot}d$ in the sealed-type reactor and in the tube-type biofilm reactor was $2.8{\sim}18.8g-H_2S/m^2{\cdot}d$.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.4 s.48
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• pp.471-477
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• 2004

Exposure to elevated temperatures, chemical (active oxigen), or physical stress (UV light) induces immediate physiological response, the expression of heat shock proteins in cells. Thus, cells with elevated Heat Shock Protein levels become more tolerant to stress conditions that are otherwise lethal. First, we studied on the new function of glucuronic acid (GA) as preventive material of skin aging. The application of the GA shows significant induction of Heat Shock Protein 70 kDa (HSP 70 kDa) in contrast to cells without it. GA at the concentration which can induce HSP 70 kDa, protects the cell death induced by second stress (heat shock and hydrogen peroxide) in NIH3T3 cells. Second, we studied on in vitro transdermal permeation characteristic of GA through the excised mouse skin. In this study, we compared the skin permeability of GA in water with O/W emulsion. As a result, skin permeation parameters of GA shows lag time 1.2 h, partition coefficient 0.114, permeation flult rate $0.83114 mg/cm^2/h.$ In case of lag time, O/W emulsion containing GA increase 2.48 h. Also, the total accumulation permeation content decreased in contrast to GA solution after 24 h. But it has long-term permeability of glucuronic acid. These results suggest that glucuronic acid could be a good cosmetic active ingredient.

• Korean Journal of Microbiology
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• v.32 no.1
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• pp.84-90
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• 1994

Kinetic parameters of various substrates and inhibitors were measured to elucidate the binding requirements of the active site of intracellular adenosine deaminase (ADA) in Aspergillus oryzae. 3'-Deoxyadenosine was the best substrate according to the value of relative kcat/$K_m$. Purine riboside was found to be the strongest inhibitor with the $K_i$ value of $3.7{\times}10^{-5}$M. Adenine acted neither as a substrate nor as an inhibitor, suggesting the presence of ribose at N-9 of adenosine was crucial to binding. ADA also catalyzed the dechlorination of 6-chloropurine riboside, generating inosine and chloride ions. Substrate specificity of 6-chloropurine riboside was 0.86% of adenosine. Purine riboside, a competitive inhibitor of ADA, inhibit the dechlorination with similar $K_i$ value, suggesting that the same binding site was involved in deamination and dechlorination. Among the sulfhydryl group reagents, mercurials, pchloromercuribenzoate (PCMB), mersalyl acid and $HgCl_2$ inactivated the enzyme. Mersalyl acid-inactivated ADA was reactivated by thiol reagents, but PCMB-inactivated enzyme was not. When ADA was treated with the mercurial reagents, the inhibition constants and inhibition patterns were determined. Each inhibition was competitive with substrate. The $K_i$ values of these mercurial reagents were lower in 10 mM phosphate buffer than in 100 mM phosphate buffer, showing phosphate dependency.

• Journal of the Korean earth science society
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• v.32 no.6
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• pp.640-653
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• 2011

We simulate the propagation of earthquake waves in the continental margin of Antarctica using the elastic wave modeling algorithm, which is modified to be suitable for acoustic-elastic coupled media and earthquake source. To simulate the various types of earthquake source, the staggered-grid finite-difference method, which is composed of velocity-stress formulae, can be more appropriate to use than the conventional, displacement-based, finite-difference method. We simulate the elastic wave propagation generated by earthquakes combining 3D staggered-grid finite-difference algorithm composed of displacement-velocity-stress formulae with double couple mechanisms for earthquake source. Through numerical tests for left-lateral strike-slip fault, normal fault and reverse fault, we could confirm that the first arrival of P waves at the surface is in a good agreement with the theoretically-predicted results based on the focal mechanism of an earthquake. Numerical results for a model made after the subduction zone in the continental margin of Antarctica showed that earthquake waves, generated by the reverse fault and propagating through the continental crust, the oceanic crust and the ocean, are accurately described.

• Journal of the Korean earth science society
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• v.36 no.1
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• pp.16-26
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• 2015

To investigate the applicability of physical prospecting technique in soft ground assessment, the resistivity monitoring data of 6 months are acquired. The Multichannel Analysis Surface Wave (MASW) has been additionally performed to identify the shear wave velocity and strength distribution of soft ground. Moreover, by using the Cone Penetration Test (CPT) and laboratory tests of drilling samples, a relationship with the physical prospect data is checked and the reliability of the physical prospect data is increased. Through these activities, the behavior patterns of soft soil are identified by long term monitoring, and the significant relationship between the shear wave velocity and laboratory tests has been confirmed, both of which can be useful in the surface wave exploration to evaluate the strength of soft ground. Finally, using the geostatistical method, 3-dimensional soil base distribution images are obtained about the combined physical prospecting data with heterogeneous data. Through the studies, the nature of entire area can be determined by long term resistivity monitoring for the soft ground assessment in wider area. It would be more economic and reliable if additional exploring and drilling samples can be analyzed, which can reinforce the assessment.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1377-1387
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• 2013

Most embankment of the reservoirs (99.1 %) have been constructed in the earth filled type in Korea because the construction of this type is less expensive and simpler than others such as concrete one. However, it has to be reinforced the slope to prevent the breach due to overtopping or piping under unexpected flood conditions. This study has been analyzed the retardation effect using three types (L, T, $L^*$ shape) of stiffener in order to reinforce embankment when they are collapsed by overtopping flow. Experimental results showed that L-type stiffener is the most effective in delaying the breaching of embankment and reducing the soil erosion when compared with others. The reinforced embankment breaching showed that time delay was occurred about 1.73 to 2.29 times and the peak flowrate was reduced compared to non-stiffener embankments due to energy dissipation by collision and less soil erosion. The embankment breaching mostly leads to major damages because of the lack of repair time. Thus, since these stiffeners can resist the rapid breach, it would be possible to earn the time to emergency repair and lifesaving, as well as reduction of damages of embankment in downward region with decreasing peak flowrate. Results from this study would be used for the basis when establishing the emergency action plan for the reservoirs on the verge of hazard.

• Journal of Korean Society of Transportation
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• v.29 no.2
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• pp.37-45
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• 2011

The main objective of this study is two-fold: 1) to analyze the effect of PG technology application on road user's satisfaction and driving speed, and 2) to investigate the relationship between driver's subjective workload level and their reactions related to the PG technology application. Based on the result of field observation, the experimental scenario for driving simulation study was prepared. The experimental results showed that drivers were more satisfied to the road condition with PG technology applied, and even the pattern of speed reduction was more stable than control condition. The pattern of speed reduction along driver's subjective driving workload level were slightly different by physical road condition, and road user's satisfaction was revealed to be negatively correlated with their subjective driving workload level. This result indicates that depending on situation and driver characteristic, information for the drivers could be nothing more than nuisance that just distracts drivers. In order to facilitate the implementation of PG technology in Korea, further study on related human factors, especially for those who are weak in traffic situations, is recommended.

• Journal of Veterinary Clinics
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• v.22 no.4
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• pp.297-301
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• 2005

This study was performed to evaluate the effects of the combination of electroacupuncture (EA) and surgical decompression on paraplegia due to spinal compression in dogs. Ten clinically healthy dogs were assigned into two groups (group A and group B). The one is for the combination of EA and surgical decompression, and the other is for surgical decompression alone. After decompression, neurological function was evaluated daily with modified Tarlov grading system. SEPs were measured as objective evaluation of normal spinal cord function before spinal compression and after neurological recovery. The period of rehabilitation in group A was significantly shorter than that in group B (p<0.05). Conduction velocity of SEPs showed a tendency to return to normal when the dogs got full recovery. According to these results, it was considered that the EA with surgical decompression was more effective than surgical decompression alone for paraplegia resulting from spinal cord injury in dog.