• The Journal of Engineering Geology
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• v.15 no.4 s.42
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• pp.407-421
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• 2005

This study aims to investigate hydrogeological properties of the central area from Yangjeong-Dong to Sujeong-Dong in Busan Metropolitan City. For this study, pumping tests were carried out in the bedrock aquifer of Yangjeong-Dong and the unconsolidated aquifer near Busanjin railway station. The pumping test in the bedrock aquifer containing the Dongrae fault revealed specific hydraulic characteristics with respect to the fault. The pumping test in the unconsolidated aquifer revealed the hydrogeologic properties of both coastal landfill and fine sediments. It was found that the Moench's sphere-shaped dual-porosity model fits the bedrock aquifer, whereas the Neuman's uncofined aquifer model accords with the unconsolidated aquifer. The average transmissivity and storage coefficient of the bedrock aquifer are $2.75{\times}10^{-5}m^2/s\;and\;6.41{\times}10^{-5}$ and those of the unconsolidated aquifer are $8.24{\times}10^{-4}m^2/s\;and\;3.70{\times}10^{-3}$, respectively. On the other hand, slug tests gave average transmissivity and storage coefficient values of $9.84{\times}10^{-4}m^2/s\;and\;1.21{\times}10^{-2}$, respectively.

• Journal of the Korean Society of Food Culture
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• v.12 no.2
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• pp.189-193
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• 1997

A study was conducted to investigate the effects of deodorizing temperature on physicochemical characteristics, fatty acid and triglyceride (TG) composition, and to estabilish the optimal deodorizing conditions in corn oil. Acid value (AV) of $240^{\circ}C$ treating group was showed 0.065 as the lowest level, the AV range was $0.08{\sim}0.09$ at $250{\sim}270^{\circ}C$. Lovibond total color was 24 as the lowest level, peroxide values (POV) were zero at $240{\sim}270^{\circ}C$ range. But POV was showed 0.42 meg/kg oil at $235^{\circ}C$, according to the optimal deodorizing temperature for the complete removal of peroxides was required more than $240^{\circ}C$. On the other hand, inclose of deodorizing temperature was conducted to the increase of saturated fatty acid content as myristic, palmitic, stearic and arachidic acid etc. Change of TG composition at treated group more than $250^{\circ}C$ was reliable, $S_3$ type TG was appeared. As a result, high temperature deodorizing was induced the undesirable influence at the physicochemical properties in deodorized corn oil.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.464-473
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• 2016

The air temperatures of the coast and inland are rising due to an increase in carbon dioxide emissions and abnormal climate phenomena caused by global warming, El Nino, La Nina and so on. The sea levels of the Earth are rising by approximately 2.0 mm per year (global average value) due to the thermal expansion of sea water, melting of glaciers and other causes by global warming. On the other hand, when it comes to designing a hydraulic structure or coastal hydraulic structure, the standard of the design water level is decided by analyzing four largeness tide values and a harmonic constant with the observed tidal water level or simulating numerical model. Therefore, the design tidal water level needs to consider an increasing speed of the seawater level, which corresponds to the design frequency. In the present study, the observed tidal water levels targeting 46 tidal stations operated by the Korea Hydrographic and Oceanographic Administration (KHOA) from the beginning of observations to 2015 per hour were collected. The variation of the monthly and yearly and increasing ratio were performed and divided into 7 seas, such as east and west part of the Southern Sea, south part and middle of the East Sea, south part and middle of the Western Sea, and Jeju Sea. The current study could be used to determine the cause of local seawater rises and reflect the design tidal water level as basic data.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.7
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• pp.38-45
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• 2006

The superconducting fault current limiters(SFCLs) provide the effect such as enhancement in power system reliability due to limiting the fault current within a few miliseconds. Among various SFCLs we have developed a flux-lock type SFCL and exploited a special design to effectively reduce the fault current according to properly adjustable magnetic field after the short-circuit test. This SFCL consists of two copper coils wound in parallel on the same iron core and a component using the YBCO thin film connected in series to the secondary copper coil. Meanwhile, operating characteristics can be controlled by adjusting the inductances and the winding directions of the coils. To analyze the operational characteristics, we compared closed-loop with open-loop iron core. When the applied voltage was 200[Vrms] in the additive polarity winding, the peak values of the line current the increased up to 30.71[A] in the closed-loop and 32.01[A] in the open-loop iron core, respectively. On the other hand, in the voltages generated at current limiting elements were 220.14[V] in the closed-loop and 142.73[V] in the opal-loop iron core during first-half cycle after fault instant under the same conditions. We confirmed that the open-loop iron core had lower power burden than in the closed-loop iron core. Consequently, we found that the structure of iron core enabled the flux-lock type SFCL at power system to have the flexibility.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.2
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• pp.100-109
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• 2018

The emergence and dissemination of multidrug-resistant (MDR) Acinetobacter baumannii isolates have been reported worldwide, with most of these possessing the ability to form biofilms. Biofilm formation is an important virulence factor associated with the resistance to disinfection and desiccation. This study examined the genetic basis of antimicrobial resistance mechanisms of biofilm-forming A. baumannii clinical isolates. Imaging and quantification of biofilms were performed by a crystal violet assay and 46 biofilm-forming A. baumannii isolates were selected. Subsequently, 16 isolates belonging to different clones were identified using REP-PCR, and detection of the antimicrobial determinants in the isolates was carried out. The 16 isolates included 9 non-MDR and 7 MDR isolates. The mean biomass $OD_{560}$ values of the non-MDR (0.96) and MDR (1.05) isolates differed but this difference was not significant. In this study, most biofilm-forming MDR A. baumannii isolates contained various antimicrobial resistance determinants ($bla_{OXA-23}$, armA, and mutations of gyrA and parC). On the other hand, most biofilm-forming non-MDR A. baumannii isolates did not contain antimicrobial resistance determinants. These results suggest that there is little correlation between the biofilm-forming ability and antimicrobial susceptibility in A. baumannii isolates. In addition, the emergence of MDR A. baumannii clinical isolates is generally caused by mutations of the genes associated with antimicrobial resistance and/or the acquisition of various antimicrobial resistance determinants.

• Korean Journal of Food Science and Technology
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• v.4 no.4
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• pp.259-264
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• 1972

Oxidative changes of the Ramyon lipids were studied under three experimental storage conditions. Ramyon was 1) exposed to fluorescent light irradiation at $25^{\circ}C$, 2) incubated in the dark at $40^{\circ}C$ and 3) irradiated with ultra-violet light at $25^{\circ}C$. In the study, changes in acid value, peroxide value, carbonyl value, TBA number, fatty acid composition and iodine value were determined with the lipids extracted from the Ramyon samples in intervals for a period of 20 weeks. Acid value, peroxide value, and TBA number of the samples under fluorescent light irradiation and $40^{\circ}C$ incubation increased slightly during storage, while a sharp increase of those values were noticed with the samples of ultra-violet light irradiation. Especially, the TBA number of the Ramyon lipid under ultra-violet light irradiation markedly increased within 10 weeks and then decreased. With this change in TBA number, however, the bound form of malonaldehyde increased gradually. During the storage under $40^{\circ}C$ incubation, and ultra·violet irradiation for 10 weeks, the content of linoleic and linolenic acids decreased, while palmitic and stearic acids increased. However, only small changes were noticed in iodine value of the samples. On the other hand, oxidative rancid odor appeared at the end of 16 weeks storage under fluorescent light irradiation and $40^{\circ}C$ incubation, while it took only 4 weeks with the sample stored under ultra-violet irradiation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.6 no.1_2
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• pp.65-75
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• 1973

Morphological variations of the Korean Oyster, Crassostrea gigas, were studied on the basis of the oyster samples collected from seven ecologically different areas in May and October of 1972 respectively. The sampling areas were Daecheon and Buan in the west coast, Namseong, Cha-myeon, Imyeong and Chubong in the south coast and Pohang in the east coast. The average sizes of the oysters of the west coast were smaller than those of the south coast as well as those of the east coast. The oysters of the east were largest in size, The oysters from subtidal habitats (Chubong and Pohang) had elongated shells and those from intertidal habitats (Buan, Namseong, Imyeong and Chamyeon) had slanted shells. The samples from subtidal habitats showed size variations depending on cultural methods applied. The oysters from Chubong reared by hanging method had their shells as compared to those from Pohang reared by bottom culture method. The ratio of shell height to shell length showed a great variation froms areas to areas with a significant differences. The fatness (meat weight / shell weight) of all the samples collected in October revealed higher value than those collected in May. The oysters from Chubong showed maximum fatness, and those of Pohang showed minimum fatness. Seasonal variations in fatness was not significant in Chubong. On the other hand, it was relatively significant in the oysters from Pohang, Chamyeon, Imyeong and Buan. Water content of the oyster meat was greater in October than in May. It also showed variations in the sampling areas with higher values in the oyster from Imyeong and Chamyeon than those from Chubong, Pohang and Daecheon.

• Journal of the Korean GEO-environmental Society
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• v.13 no.10
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• pp.69-76
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• 2012

This study focuses both on the quantitative measurement of hydroxyl radicals formed by an electron beam (E-beam) process and on the decomposition of pentachlorophenol(PCP) in the presence of $H_2O_2$ and $Fe^{3+}-EDTA$ as additives. To attain this objective, the quantitative measurement of hydroxyl radical was performed with the hydroylation of benzoic acid (BA), producing hydroxybenzoic acid (OHBA). As a result, the concentrations of hydroxyl radical measured were lower than those of hydroxyl radical predicted. Probably, it indicates that the reactive species generated during E-beam irradiation are able to scavenge the hydroxyl radicals. In particular, the degradation of PCP was promoted by the addition of $H_2O_2$ (< 1mM). On the other hand, its degradation as well as the generation of chloride ions as a by-product was inhibited by the addition of $H_2O_2$ (> 1mM), and thus carbon yield(%) of oxalic acid as a by-product was increased. During E-beam irradiation the addition of $Fe^{3+}-EDTA$ effectively decomposed the PCP, thus increasing the G-values. Considering the formation of OHBA and the decomposition of PCP, these results suggest that the addition of $Fe^{3+}-EDTA$ in the E-beam process can produce the further hydroxyl radicals and enhance the efficiency of PCP decomposition at low dose.

• Journal of the Korean Magnetics Society
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• v.25 no.4
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• pp.117-122
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• 2015

The holes with a diameter of $35{\mu}m$ inside the GMR-SV (giant magnetoresistance-spin valve) film were patterned by using the photolithography process and ECR (electron cyclotron resonance) Ar-ion milling. From the magnetoresistance curves of the GMR-SV film with holes measuring by 4-electrode method, the MR (magnetoresistance ratio) and MS (magnetic sensitivity) are almost same as the values of initial states. On other side hand, the $H_{ex}$ (exchange bias coupling field) and $H_c$ (coercivity) dominantly increased from 120 Oe and 10 Oe to 190 Oe and 41 Oe as increment of the number of holes inside GMR-SV film respectively. These results were shown to be attributed to major effect of EMD (easy magnetic domian) having a region positioned between two holes perpendicular to the sensing current. On the basis of this study, the fabrication of GMR-SV applying to the hole formation improved the magnetoresistance properties having the thermal stability and durability of bio-device.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.2
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• pp.149-155
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• 2017

This study was carried out to investigate the hair protection effect of fermented black soybean extracts. The morphological characteristics, tensile strength and constitutional changes of the hair were analyzed and compared when the hair was chemically oxidized and then treated with fermented black soybean extract. As a result, treatment of oxidizing agent on virgin hair caused damage on the cuticle layer of the epidermis and decreased in tensile strength of hair from $14.32{\pm}0.83g/cm^2$ to $12.32{\pm}0.79g/cm^2$. FT-IR analysis showed the peaks at 1,077, 1,041, and $801cm^{-1}$ of the hair treated with oxidizing agent were increased compared to peak values of virgin hair, indicating that cystein in hair was decreased which is crucial to disulfide bond between keratin. On the other hand, when the damaged hair is treated with the fermented black soybean extract, cracks in the cuticle layer of the epidermis were filled, tensile strength was restored to $14.27{\pm}0.96g/cm^2$ and the ratio of oxidized cysteine in hair was decreased. These results suggest that the fermented black soybean extract is worthy of further investigation as a protective material for hair damaged by oxidizing agents.