• Food Engineering Progress
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• v.13 no.1
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• pp.16-23
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• 2009

Onion juices supplemented with different concentrations of puffed red ginseng extract were fermented using Pediococcus pentosaceus KC-007 and their biologically functional properties were investigated. When onion juices were supplemented with puffed red ginseng extract at the concentration of 0.5, 1, 2, and 4% (v/v) each, viable cell number of lactic acid bacteria was the highest at 24 hr of fermentation in all samples. The titratable acidity increased as the fermentation proceeds irrespective of the added amount of red ginseng extract, and the pH of fermentation broth decreased until 36 hr of fermentation. The reducing sugar of fermentation broth decreased until 24 hr of fermentation and did not change thereafter. The electron donating ability and nitrite scavenging ability were highest when red ginseng extract was added at the concentration of more than 1% (w/v). The overall acceptance in sensory evaluation was the best when red ginseng extract was added at the concentration of 1% (w/v). From these results, it is confirmed that the optimum concentration of puffed red ginseng extract for the lactic acid fermentation of onion juice was 1% (w/v).

• Journal of the Korean Geotechnical Society
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• v.25 no.8
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• pp.33-45
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• 2009

The conventional single-core PBDs have been widely used in order to accelerate consolidation settlement of soft grounds. When using the single-core PBD in a thick clay deposit, a delay of consolidation may occur due to high confining pressure in the thick deposit and necking of drains. This study is to compare the performances of soil improvement by the single-core and double-core PBD installed at a site in Busan New Port which exhibits approximately a 40m-thick clay layer. An in-situ test program was performed at the test site where a set of the double-core PBDs and single-core PBDs were installed to compare the efficiency of each drain. In addition, the discharge capacity of each PBD has been measured using the modified Delft Test. A series of laboratory tests for estimating in-situ soil properties have also been performed in order to obtain input parameters for a numerical program ILLICON. The discharge capacity of the double-core PBD is higher than that of the single-core PBD in the modified Delft Test. However it is observed from the comparative in-situ test and numerical analysis that there is no difference in the performance of ground improvement between the two drain systems. This discrepancy comes from the fact that the amount of water released during consolidation in most common field conditions is much smaller than the capacity of even the single core PBD. And thus, considering actual field conditions, it can be concluded that the single-core PBD has enough discharge capacity even in the thick clay deposit such as this test site.

• 대한공업교육학회지
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• v.33 no.2
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• pp.192-217
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• 2008

This paper investigated the perceived criticalities and patterns of Korean Professional Engineer's competency regarding the working activities of automative product development, manufacturing, etc by using questionnaires responded to the survey which were applied to the automotive professors, experts and professional engineers (vocational parties) by e/mail, etc. This research investigated the following questions: First, what are the characteristic patterns, relevancy and perceived criticalities of Korean Professional Engineer's competencies? Second, What are the ranked priority of the Korean Professional Engineers' competencies? Are there any differency for each item, sub group of job, intelectual criterior of the competencies between relevancy and perceived criticalities according to the types of vocational parties, etc.? Accoring to the results; first, Professor group showed highest points among 3 groups per each item of the competencies by vocational parties Second, Chassis design group ranked top position among the 8 sub groups by vocational parties and, third, Problem Solving Knowledge ranked highest points than any others. Korean Professional Engineers are found to be positioned as key members, leaders and managers on surveying market, product planning, designing product & components, developing component parts, establishing shop with production equipment, managing quality control & material handling, organizing relevant meetings, developing human resources by training and learning, to back up finance with law matters, cooperating with concerned parties to achieve organizational goals, and to coordinate projects. etc, identifying ethical issues and business skills in order to survive and win to be competitive in various kinds of the automotive industry battle fields.

• Economic and Environmental Geology
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• v.54 no.4
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• pp.409-425
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• 2021

Carbon dioxide has been known to be a typical greenhouse gas causing global warming, and a number of efforts have been proposed to reduce its concentration in the atmosphere. Among them, carbon dioxide capture and storage (CCS) has been taken into great account to accomplish the target reduction of carbon dioxide. In order to commercialize the CCS, its safety should be secured. In particular, if the stored carbon dioxide is leaked in the arable land, serious problems could come up in terms of crop growth. This study was conducted to investigate the effect of carbon dioxide leaked from storage sites on soil fertility. The leakage of carbon dioxide was simulated using the facility of its artificial injection into soils in the laboratory. Several soil chemical properties, such as pH, cation exchange capacity, electrical conductivity, the concentrations of exchangeable cations, nitrogen (N) (total-N, nitrate-N, and ammonia-N), phosphorus (P) (total-P and available-P), sulfur (S) (total-S and available-S), available-boron (B), and the contents of soil organic matter, were monitored as indicators of soil fertility during the period of artificial injection of carbon dioxide. Two kinds of soils, such as non-cultivated and cultivated soils, were compared in the artificial injection tests, and the latter included maize- and soybean-cultivated soils. The non-cultivated soil (NCS) was sandy soil of 42.6% porosity, the maize-cultivated soil (MCS) and soybean-cultivated soil (SCS) were loamy sand having 46.8% and 48.0% of porosities, respectively. The artificial injection facility had six columns: one was for the control without carbon dioxide injection, and the other five columns were used for the injections tests. Total injection periods for NCS and MCS/SCS were 60 and 70 days, respectively, and artificial rainfall events were simulated using one pore volume after the 12-day injection for the NCS and the 14-day injection for the MCS/SCS. After each rainfall event, the soil fertility indicators were measured for soil and leachate solution, and they were compared before and after the injection of carbon dioxide. The results indicate that the residual concentrations of exchangeable cations, total-N, total-P, the content of soil organic matter, and electrical conductivity were not likely to be affected by the injection of carbon dioxide. However, the residual concentrations of nitrate-N, ammonia-N, available-P, available-S, and available-B tended to decrease after the carbon dioxide injection, indicating that soil fertility might be reduced. Meanwhile, soil pH did not seem to be influenced due to the buffering capacity of soils, but it is speculated that a long-term leakage of carbon dioxide might bring about soil acidification.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.10
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• pp.1500-1509
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• 2014

The object of this study was to investigate the inhibitory effects of chios mastic gum (MG) on gastric acid secretion in an ethanol-induced SD rat model and primary parietal cells. Rats were randomly divided into four groups: Vehicle (normal group), Control (treated with ethanol), MG50 (treated with ethanol and mastic gum at 50 mg/kg b.w), MG100 (treated with ethanol and mastic gum at 100 mg/kg b.w). Groups treated with both MG50 and MG100 showed attenuation of gastric mucosal injury, sub-epithelial loss, hemorrhaging, and gastric juice secretion. We also examined the acidity of gastric juice during gastric injury. Oral administration of both MG50 and MG100 significantly decreased acidity of gastric juice by % and %, respectively. To examine the stimulatory factors related to gastric acid secretion, mRNA expression levels of H2r, M3r, CCK2r, and $H^+/K^+$ ATPase were measured by real-time PCR. Compared with a vehicle group, mRNA expression levels of H2r, CCK2r, and $H^+/K^+$ ATPase clearly increased in the control group. However, levels of H2r, CCK2r, and $H^+/K^+$ ATPase slightly but significantly decreased in MG-treated groups compared with control. Blood level of histamine significantly decreased in MG-treated groups, which indicates the involvement of MG on in histamine-related acid secretion. To identify the mode of action of MG in regulating histamine-related pathways, intracellular level of cAMP and mRNA levels of H2r, M3r, CCK2r, and $H^+/K^+$ ATPase were measured in primary parietal cells. While mRNA levels of M3r and CCK2r remained unchanged, levels of H2r and $H^+/K^+$ ATPase significantly decreased upon MG treatment. Subsequently, intracellular levels of cAMP decreased. These results suggest that mastic gum has the ability to inhibit gastric acid secretion by regulating a histamine-related pathway.

• Economic and Environmental Geology
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• v.55 no.4
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• pp.377-388
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• 2022

Laboratory-scale experiments were performed to identify the As removal mechanism of the residual slag generated after the mineral carbonation process. The residual slags were manufactured from the steelmaking slag (blast oxygen furnace slag: BOF) through direct and indirect carbonation process. RDBOF (residual BOF after the direct carbonation) and RIBOF (residual BOF after the indirect carbonation) showed different physicochemical-structural characteristics compared with raw BOF such as chemical-mineralogical properties, the pH level of leachate and forming micropores on the surface of the slag. In batch experiment, 0.1 g of residual slag was added to 10 mL of As-solution (initial concentration: 203.6 mg/L) titrated at various pH levels. The RDBOF showed 99.3% of As removal efficiency at initial pH 1, while it sharply decreased with the increase of initial pH. As the initial pH of solution decreased, the dissolution of carbonate minerals covering the surface was accelerated, increasing the exposed area of Fe-oxide and promoting the adsorption of As-oxyanions on the RDBOF surface. Whereas, the As removal efficiency of RIBOF increased with the increase of initial pH levels, and it reached up to 70% at initial pH 10. Considering the PZC (point of zero charge) of the RIBOF (pH 4.5), it was hardly expected that the electrical adsorption of As-oxyanion on surface of the RIBOF at initial pH of 4-10. Nevertheless it was observed that As-oxyanion was linked to the Fe-oxide on the RIBOF surface by the cation bridge effect of divalent cations such as Ca²⁺, Mn²⁺, and Fe²⁺. The surface of RIBOF became stronger negatively charged, the cation bridge effect was more strictly enforced, and more As can be fixed on the RIBOF surface. However, the Ca-products start to precipitate on the surface at pH 10-11 or higher and they even prevent the surface adsorption of As-oxyanion by Fe-oxide. The TCLP test was performed to evaluate the stability of As fixed on the surface of the residual slag after the batch experiment. Results supported that RDBOF and RIBOF firmly fixed As over the wide pH levels, by considering their As desorption rate of less than 2%. From the results of this study, it was proved that both residual slags can be used as an eco-friendly and low-cost As remover with high As removal efficiency and high stability and they also overcome the pH increase in solution, which is the disadvantage of existing steelmaking slag as an As remover.

• Journal of the Korean Applied Science and Technology
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• v.41 no.1
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• pp.9-18
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• 2024

Smilax china is known for its excellent antimicrobial, antioxidant, and anti-inflammatory properties. As a foundational study for applying the functionality of Smilax china extracts to cosmetics, it is necessory to investigate the concentration-dependent skin permation characteristics of the flavonoids in the extract, namely quercetin, catechin, and naringenin. Therefore, it serves as a crucial method for conducting this basic research on the functional aspects fo Smilax china extracts for cosmetic applications. This investigation focused on examining the percutaneous permeability characteristics of flavonoids originating from Smilax china. Applying Marzulli's definition, the Kp value of quercetin was categorized as "fast" at 0.1 mg/mL and "moderate" at 0.2 and 0.4 mg/mL. Notably, the permeation rate exhibited a decline with increasing concentration. For naringenin, Flux values were 0.69, 1.07, and 1.42 ㎍/hr/cm² at concentrations of 0.1, 0.2, and 0.4 mg/mL, respectively, with corresponding Kp values of 6.95, 5.34, and 3.56. Naringenin's Kp value fell into the "moderate" category across all concentrations, and as observed with quercetin, the permeation rate decreased with higher concentrations. Likewise, for catechin, Flux values were 0.75, 1.09, and 1.66 ㎍/hr/cm², and corresponding Kp values were 7.55, 5.46, and 4.16. Catechin's Kp value was consistently classified as "moderate" across all concentrations. The efficacy of quercetin, catechin, and naringenin, active ingredients in high-performance and anti-inflammatory Smilax china extracts, was found to exhibit skin penetration properties above the average. This confirms their suitability as excellent natural materials for use in functional cosmetics, given their outstanding capabilities in preventing acne and reducing inflammation.

• Korean Journal of Food Science and Technology
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• v.41 no.5
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• pp.541-546
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• 2009

The objectives of this study were to evaluate the physico-chemical and sensory characteristics of a Korean traditional alcoholic beverage (yakju) prepared using different nuruk (Korean-style koji) concentrations and yeasts such as the fusant FA776 and Saccharomyces cerevisiae KOY-1, respectively. The fusant FA776, which has alcohol-fermenting and starch-utilizing properties, was formed by Saccharomyces cerevisiae KOY-1 and Saccharomyces diastaticus KCTC1804. The fermentation trial was conducted in a 5 L lab-scale jar at $25^{\circ}C$. The maximum alcohol production of the K-100 and F-50 reached levels of 135.0 mg/mL and 119.4 mg/mL, respectively. The pH values were in a range of 4.3-4.5. Total acidity was in a range of 0.47-0.60%. Organic acids and amino acids were analyzed in order to evaluate variations in its composition and content via HPLC analysis. Organic acids including lactic acid, citric acid, malic acid, and pyruvic acid, and 16 kinds of amino acids, including aspartic acid, were detected in all treatments. K-100 showed the highest amino acid contents, whereas F-50 exhibited the lowest amino acid contents. Volatile flavor components such as phenylethyl alcohol, isoamyl alcohol, 2-methylthiophane, isobutyl alcohol, and ethyl succinate were detected as a major component in all treatments, as determined via gas chromatography. The results of our sensory evaluation demonstrated that Yakju fermented by the FA776 fusant yielded more favorable results than S. cerevisiae KOY-1.

• The Journal of the Petrological Society of Korea
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• v.9 no.2
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• pp.70-83
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• 2000

The purpose of this study is to identify the petrographic and geochemical characteristics of four granitic masses and clanfy for the origin and relationship among the masses. These granitic rocks are distributed in the eastern part of Yangsan fault in the Kyongsang basin, southeastern part of Korea. Based on the mineralogy and texture, the granitic rocks are divided into three facies; granodiorite, porphyritic fine-grained granite, and equigranular granite. According to the result of modal analysis, northern part and most of the southern part of Daebon granitic rocks are plotted in granodiorite field and the rest part of the xocks are plotted in granite field. These granitic rocks belong to the sub-alkaline series, and are subdivided into calc-alkaline series. The rare earth elements normalized bv chondrite show LREE is more enriched than HREE and the lowest values in O-w m- i t e and Daebon equigranular granite. The crystallization pressures and temperatures of minimum melt compositions of granitic rocks estimated from the study area are about 0.5-1 kbar and $700~820^{\circ}C$, respectively. Referring to the petrographic characteristics, geochemical data and radiogenic age data, Oyu granite was emplaced in the Paleocene, but Daebon granodiorite, Sanseo porphyritic granite, and Hoam equigranular granite are co-magmatic differentiation products, were emplaced in the Eocene.

• Progress in Medical Physics
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• v.11 no.1
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• pp.39-47
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• 2000

In Stereotactic Radiosurgery (SRS), there are three imaging methods of target localization, such as digital subtraction Angiography (DSA), computed tomography (CT), magnetic resonance imaging (MRI). Especially, DSA and MR images have a distortion effect generated by each modality. In this research, image properties of DSA were studied. A first essential condition in SRS is an accurate information of target locations, since high dose used to treat a patient may give a complication on critical organ and normal tissue. Hut previous localization program did not consider distortion effect which was caused by image intensifier (II) of DSA. A neurosurgeon could not have an accurate information of target locations to operate a patient. In this research, through distortion correction, we tried to calculate accurate target locations. We made a grid phantom to correct distortion, and a target phantom to evaluate localization algorithm. The grid phantom was set on the front of II, and DSA images were obtained. Distortion correction methods consist of two parts: 1. Bilinear transform for geometrical correction and bilinear interpolation for gray level correction. 2. Automatic detection method for calculating locations of grid crosses, fiducial markers, and target balls. Distortion was corrected by applying bilinear transform and bilinear interpolation to anterior-posterior and left-right image, and locations of target and fiducial markers were calculated by the program developed in this study. Localization errors were estimated by comparing target locations calculated in DSA images with absolute locations of target phantom. In the result, the error in average with and without distortion correction is $\pm$0.34 mm and $\pm$0.41 mm respectively. In conclusion, it could be verified that our localization algorithm has an improved accuracy and acceptability to patient treatment.