• Journal of Conservation Science
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• v.35 no.2
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• pp.131-144
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• 2019

The Seosan Geomenyeo(black submerged rocks), once located at the Cheonsuman bay of Buseokmyeon in Seosan, Korea, is a reef rock now exposed on the land surface. The Geomenyeo can also be found in the ancient geographic maps around the area. The local geographic names, like Buseok and Buseoksa temple are derived from the Geomenyeo. It is composed of ultramafic rocks complex and intrusive felsic igneous rocks. These rocks show diverse facies with various petrographic characteristics caused by geological processes such as intrusion and alteration. Ultramafic rocks complex can be roughly categorized as coarse grained ultramafic rocks and medium grained mafic rocks. Both cases are composed of pyroxene and amphibole, showing the general rock facies of pyroxenite, diabase and lamprophyre. Felsic igneous rocks includes pinkish medium grained granite, porphyritic amphibole granite and aplite with varied mineral compositions. The Geomenyeo is the only ultramafic rocks complex in the Cheonsuman Bay; moreover, it has a distinctive geological and scenic value, as well as a symbolic property. In order to preserve the Geomenyeo, it is necessary to investigate and promote it as a designated heritage site through academic studies, and compensate for the convenience and protection facilities. Additionally, the Geomenyeo should be evaluated as a maritime heritage site, due to the unique local culture as it succeeds the recognition of forefathers which regarded it as a local scenic site with significance.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.6
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• pp.244-250
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• 2020

β-Tricalcium phosphate (β-TCP, Ca3(PO4)2) is a kind of biodegradable calcium phosphate ceramics with chemical and mineral compositions similar to those of bone. It is a potential candidate for bone repair surgery. To improve the bioactivity and osteoinductivity of β-TCP, various ions doped calcium phosphate have been studied. Among them, Iron is a trace element and its deficiency in the human body causes various problems. In this study, we investigated the effect of Fe ions on the structural variation, degradation behavior of β-TCP. Fe-doped β-TCP powders were synthesized by the coprecipitation method, and the heat treatment temperature was set at 925 and 1100℃. The structural analysis was carried out by Rietveld refinement using the X-ray diffraction results. Fe ions existed in a different state (Fe2+ or Fe3+) with different heat treatment temperatures, and the substitution sites (Ca-(4) and Ca-(5)) also changed with temperature. The degradation rate was fastest at Fe-doped β-TCP with heated at 1100℃. The cell viability behavior was also enhanced with the substitution of Fe ions. Therefore, the substitution of Fe ion has accelerated the degradation of β-TCP and improved the biocompatibility. It could be more utilized in biomedical devices.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.715-727
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• 2020

Volcanostratigraphy in Ulleung Island is divided into 4 stratigraphic groups: Dodong Basaltic Rocks, Ulleung Group, Seonginbong Group and NariGroup. The main pyroclastics in them includes lapilli tuff intercalated within the Dodong Basaltic Rocks, lapilli tuff at the top of Sadong Breccia, Sataegam Tuff, Gombawi Welded Tuff, Bongrae Scoria Deposits, Maljandeung Tuff, Nari Scoria Deposits and Jugam Scoria Deposits. Analysing eruption types, The lapilli tuff in the Dodong Basaltic Rocks is derived from Surtseyan eruption, and the Bongrae, Nari and Jugam Scoria Deposits are caused by Strombolian eruptions or/and sub-Plinion eruptions, but the Sataegam Tuff and Maljandeung Tuff are derived from Plinian and phreatoplinian eruptions. Among them the large-scaled eruptions. In particular, the eruptions of Maljandeung were large enough to result in caldera collapse, and had falled out tephras to the eastern Korean peninsula but even Japan Islands. The magma with high potential to be still alive is judged to be trachyandesitic and phonolitic in composition. If the trachyandesitic magma explodes, it will probably result in a strombolian eruption and have a fairly low explosivity, but if the phonolitic magma explodes, it will probably result in a plinian eruption and have a much higher explosivity. If the eruption had a high explosivity, there is a possibility that it could easily be converted into a phreatoplinian eruption due to the influx of groundwater by the easy generation of fractures. These large-scaled eruptions could fall out tephras to the eastern Korean peninsula but even Japan Islands.

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.609-615
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• 2021

The aim of the present study was to investigate the mechanical properties of melt-injected poly lactic acid (PLA) composites with β-tricalcium phosphate (β-TCP). The PLA mixed with calcined PLA/β-TCP powder to be contents of 0, 10, 30, 50 wt%, respectively, was dissolved in chloroform solvent under stirring for 24 h. Then the liquid mixtures were dropped into ethanol to extract solvent. After drying, the well-dispersed PLA/β-TCP composites were granulated and melt-injected to prepare specimens for various mechanical testing. PLA/β-TCP induced the precipitation of an apatite bone-mineral phase on the surface after immersion in a human simulated body fluid (SBF) for 90 days, showing in bioactivity. Mean various mechanical properties PLA/β-TCP composite were increased up to 10-30 wt% with significantly in part and composite were decreased 50 wt% of showing in mechanical properties. In conclusion, Over 30 wt% addition of β-TCP to PLA may be not advisable to improve the mechanical properties of melt-injected polymeric composites. Results indicated that β-TCP can be used considered as potential reinforcing agent for increasing mechanical properties for PLA. Therefore, it was suggest that the additional effects of β-TCP and research on a wide range of substances.

• Korean Journal of Food Science and Technology
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• v.54 no.3
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• pp.264-271
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• 2022

In this study, the nutritional properties of sterilized and non-heat-pressed raw perilla oil (SRPO) were studied and its potential as a functional food was evaluated. The copper, cobalt, and calcium levels were high in sterilized and SRPO. The total polyphenol content and ABTS radical scavenging activity were the highest in SRPO, whereas nitrite scavenging activity was the highest in 45℃ cold pressed perilla oil (CPPO). The above results confirmed that sterilized and non-heat-pressed perilla oil had high mineral and total polyphenol contents, as well as ABTS radical scavenging activity and nitrite scavenging ability. The peroxide value of SRPO decreased as the storage period increased, and the acid value of low-temperature pressed perilla oil over 65℃ (LPPO) significantly increased. This work also provided an opportunity to develop a new method for manufacturing perilla oil, and it is hoped that these experiments will form a basis for the commercialization of perilla oil.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.2
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• pp.162-173
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• 2023

Four roe protein isolates (RPIs) from olive flounder Paralichthys olivaceus roes (OFR) were recovered by isoelectric solubilization (pH 11 and 12) and precipitation (pH 4.5 and 5.5) and investigated for their food characteristics. RPIs contained 4.5-9.6% moisture, 64.1-69.5% protein, 16.1-19.8% lipid, and 1.0-3.9% ash. The protein yields of RPIs ranged from 50.1 to 56.8%, which was significantly different depending on the recovery conditions. A difference was observed in the SDS-PAGE protein band (25-100 kDa) between the alkaline solubilization at pH 11 (RPI-1 and 2) and pH 12 (RPI-3 and 4). The major amino acids of RPIs were Leu, Lys, Asp, Glu and Ala and major mineral components were sulfur, sodium, phosphorus, and magnesium, which were significantly different from OFR (P<0.05). Additionally, the lead and cadmium content was below the chemical hazard standard of the Korean food standards code. The Hunter color and whiteness of RPIs also showed significant differences according to the treatment conditions of the ISP process (P<0.05). This suggests that protein isolates recovered from olive flounder roes have high potential as nutritional supplements.

• The Korea Journal of Herbology
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• v.38 no.5
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• pp.9-19
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• 2023

Objectives : Osteoporosis is a systemic skeletal disorder characterized by reduced bone mineral density and increased risk of fractures. Bisphosphonates and selective estrogen receptors, which are bone resorption inhibitors that are currently widely used as osteoporosis treatments, show serious side effects when administered for a long time. Research on bone resorption inhibitors that complement the problems of existing treatments is needed. The purpose of this study was to investigate the effect of inhibiting osteoclast differentiation and activity on the tuberous root of Ampelopsis japonica (Thunb.) Makino (AM). Methods : After extracting AM using distilled water and ethanol, the inhibitory effects of the two solvents on osteoclast differentiation were compared using the RANKL-induced in vitro experimental model and the TRAP assay kit. The impact of AM on bone resorption was investigated through the pit formation assay, and its effect on F-actin formation was assessed through fluorescent staining. Additionally, protein and mRNA expression levels of osteoclast differentiation markers (NFATc1, c-Fos, TRAP and ATP6v0d2) and resorption markers (MMP-9, CTK, and CA2) were analyzed via western blot and RT-PCR. Results : AM treatment significantly decreased the number of TRAP-positive cells and pit formation area. Furthermore, AM suppressed both the protein and mRNA expression of NFATc1 and c-Fos, key transcription factors involved in osteoclast differentiation and it downregulated the expression of osteoclast-associated genes such as TRAP, CTK, MMP-9, CA2, and ATP6v0d2. Conclusions : These results suggest that AM can inhibit bone resorption and osteoclast differentiation, indicating its potential for use in the treatment and prevention of osteoporosis.

• Economic and Environmental Geology
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• v.57 no.1
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• pp.83-91
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• 2024

According to the IEA (2022), global rechargeable battery demand is expected to reach 1.3 TWh in 2040. EV batteries will account for about 80% of this demand, and used EV batteries are expected to be discharged after 30 years. Used EV batteries can be recycled and reused to create new value. They can also resolve one of the most vulnerable parts of the battery supply chain: raw material insecurity. In this study, we analyzed the amount of used batteries generated by EV in Korea and their potential for reuse and recycling. As a result, it was estimated that the annual generation of used batteries for EV began to increase to more than 100,000 in '31 and expanded to 810,000 in '45. In addition, it was found that the market for recycling EV batteries in '45 could be expected to be equivalent to the production of 1 million batteries, and the market for reuse could be expected to be equivalent to the production of 36 Gwh of batteries. On the other hand, according to the plan standard disclosed by the recycling company, domestic used EV batteries can account for 11% of the domestic recycling processing capacity (pre-treatment) ('30). So it will be important to manage the import and export of used batteries in terms of securing raw materials.

• Microbiology and Biotechnology Letters
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• v.45 no.3
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• pp.250-256
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• 2017

The prevalence of infections due to pathogenic bacteria such as Edwardsiella tarda, Streptococcus parauberis, and Photobacterium phosphoreum in fish farms in Jeju Island and their management by marine-derived biomaterials was studied. In this study, we isolated eight spices type of marine-derived biomaterials from four sea areas of Jeju Island. An antibiotic disc susceptibility test confirmed that the isolated marine-derived biomaterials showed weak resistance only to oxytetracycline and penicillin and sensitivity to the other antibiotics tested, and antimicrobial activity against fish pathogens with the inhibitory zone of 22 mm, 18 mm, and 19 mm for MD-02, MD-04, and MD-06 against E. tarda strains, respectively, and 19 mm, 22 mm, 30 mm, and 29 mm for MD-01, MD-02, MD-04, and MD-06 against S. parauberis strains, respectively, while all the marine-derived biomaterials showed antibacterial activity against P. phosphoreum. Among the eight biomaterials selected, Bacillus subtilis MD-02 displayed the greatest antibacterial activity against the three tested fish pathogens and also displayed susceptibility to antibiotics. The growth of Bacillus subtilis MD-02 was greatest with the carbon source, dextrine; nitrogen source, peptone; and mineral source, $MgSO_4{\cdot}7H_2O$. Hence, the present study confirmed that the isolate B. subtilis MD-02 from Jeju Island could be a potential antimicrobial agent against fish pathogens and a potential pharmacotherapeutic agent.

• Economic and Environmental Geology
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• v.36 no.1
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• pp.27-38
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• 2003

Arsenic contamination around Au-Ag mining areas occurs mainly from the oxidation of arsenopyrite which is frequently contained in mine tailings. In weathered tailings, oxidation of sulfide minerals typically results in the formation of abundant ferric (oxy)hydroxides or (oxy)hydroxysulfates near the tailings surface, and arsenic may be associated with these secondary precipitates. In this study, solid phases of arsenic in weathered tailings of some Au-Ag mines were investigated through the SEM/EDS and sequential extraction analyses. The stability of As solid phases and the leaching potential were assessed with the variation of pH and Eh conditions. Oxidation of sulfides in the tailings samples was indicated by depletion of S molar concentrations compared to As and heavy metals. Under XRD examinations, jarosite as an Fe-oxyhydroxysulfate was found in the tailings of Deokeum, Dongil and Dadeok, and scorodite as an As-bearing crystalline mineral was identified from Dadeok which has the highest concentration of As (4.36 wt.%). Beudantite-like phases and some Pb-arsenates were also found under SEM/EDS analysis, and most of As phases were associated with Fe-(oxy)hydroxides and (oxy)hydroxysulfates despite a few arsenopyrite from Samgwang and Gubong. Sequential extraction analysis also showed that As was present predominantly as coprecipitated with Fe hydroxides from Dongil, Dadeok and Myungbong (72∼99%), and as sulfides (58%) and Fe hydroxide-associated forms (40%) from Samgwang and Gubong. In the tailings leaching experiment, As was released with high amounts by the dissolution of As-bearing Fe(oxy)hydroxysulfates in the lowest pH (2.7) conditions of Deokeum, and by desorption under alkaline conditions of Samgwang and Gubong. Higher leaching rates of arsenite(+3) were found under acidic conditions, which pose a higher risk to water quality. Changes in pH and Eh conditions coupled with microbial processes could influence the stabilities of the As solid phases, and thus, time amendments or landfilling of weathered tailings may result in enhanced As mobilization.