• The Journal of Korean Academy of Prosthodontics
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• v.53 no.1
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• pp.9-18
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• 2015

Purpose: The purpose of this study is to examine characteristics of implant surface with RBM and anodizing treatments, and to evaluate the responses of osteoblast-like cell (MG-63 cell). Materials and methods: Grade IV titanium disks were fabricated (Diameter 10 mm, thickness 3 mm). Anodizing treatment (ASD) group, RBM and anodizing treatment (RBM/ASD) group, control (machined surface) group were divided. In this study, osteoblast-like cell was used for experiments. The experiments consist of surface characteristics evaluation by FE-SEM images, energy dispersive spectroscopy and stereo-SEM. In order to evaluate cell adhesion evaluation by crystal violet assay and observe cells form by confocal laser microscopy. To assess cell proliferation by XTT assay, cell differentiation by RT-PCR and mineralization by Alizarin red S stain assay. ELISA analyzer was used for Quantitative evaluation. Comparative analysis was run by one-way ANOVA (SPSS version 18.0). Differences were considered statistically significant at P<.05. Results: In ASD group and RBM/ASD group, the surface shape of the crater was observed and components of oxygen and phosphate ions in comparison with the control group were detected. The surface average roughness was obtained $0.08{\pm}0.04{\mu}m$ in the control group, $0.52{\pm}0.14{\mu}m$ in ASD group and $1.45{\pm}0.25{\mu}m$ in RBM/ASD group. In cell response experiments, ASD group and RBM/ASD group were significantly higher values than control group in cell adhesion and mineralization phase, control group was the highest values in the proliferative phase. In RT-PCR experiments, RBM/ASD group was showed higher ALP activity than other groups. RBM/ASD group in comparison with ASD group was significantly higher value for cell adhesion and proliferation phase. Conclusion: In the limitation of this study, we are concluded that the surface treatment with RBM/ASD seems more effective than ASD alone or machined surface on cellular response.

• Journal of the Korean Geosynthetics Society
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• v.14 no.4
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• pp.59-77
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• 2015

In order to meet the new requirements for landfill materials, this study planned a study to apply mixed soil of mixing bottom ash and coastal dredged soil to the dredged ground. Coal ash generated from thermal power plant is divided into fly ash and bottom ash. In the case of fly ash, many studies have been conducted because small particles causes permeability coefficient to be small during recycling so no problem has been raised in the environmental area but the utilization of bottom ash has been limited because environmental problems have been raised during recycling due to its larger particle size and greater permeability coefficient. According to recently published studies, however, the results of the study that conducted the water analysis of leachate generated in the ground improvement section using bottom ash showed that heavy metal contamination levels were found to be within the reference value and no significant environmental problems were found so utilization of bottom ash is evaluated to increase significantly in the future. This bottom ash has the particle size of sand and only transportation costs need to be considered when providing materials because the majority has been disposed and it is judged as the most suitable material in dredging landfill in the economic aspect because most thermal power plants are located in the coast and transportation costs can be reduced by ship. Also, research on mixed soil that can maximize the effect of the construction period and construction cost savings than dredged soil is determined as needed because the demand for coastal dredging reclamation is increasing such as Saemangeum project etc. Therefore, we studied self-weight consolidation characteristics depending on sample processing and mixing method of mixed soil by carrying out interior self-weight consolidation experiments on mixed soil of mixing bottom ash and Kaolinite according to the new development needs of recent coastal reclaimed ground and these result findings are expected to be used as basic data when applying the large coastal dredged ground in the future.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.4
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• pp.288-295
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• 2014

This study was conducted to evaluate the effect of mixing time for TMR (total mixed rations) mixed with corn silage on particle size, peNDF (physically effective neutral detergent fiber), laceration, and ruminal in situ dry matter degradation. The study also aimed to evaluate the effect of consumption of the TMR on the milk yield and milk components of mid-lactational dairy cows. TMRs were mixed for 30 minutes (T1) and 50 minutes (T2) using the same material. All samples were then analyzed with a Penn State Particle Size Separator (PSPS). The particle size of T1 was significantly lower in the bottom pan (8 mm>) than that of T2 (p<0.01). $peNDF_{&gt;8.0}$ was significantly higher in T1 (17.18%) than in T2 (13.85%) (p<0.01). For ruminal in situ dry matter degradation of particle retention (>19 mm), no significant difference was found after 72 hours incubation, although T1 degradation was significantly higher after 24 hours incubation (p<0.01). Milk yield was no different between the groups of cows, whereas the milk fat from T1 fed cows was significantly higher (p<0.01). The results show that feeding TMR mixed for 30 minutes to dairy cows may improve the physical value of forage without negative effects on the milk yield and milk components.

• Journal of the Korea Concrete Institute
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• v.17 no.1 s.85
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• pp.129-137
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• 2005

In Korea, due to the insufficiency of natural aggregates and increasing needs of crushed stones, it is necessary to examine the alkali-silica reaction of the crushed stones. The reaction produces an alkali-silica reaction gel which can imbibe pore solution and swell to generate cracks that are visible In affected concrete. In general, crushed stones are tested by petrograptuc examination, chemical method and mortar-bar method, but the most reliable method Is mortar-bar test. This study tested alkali-silica reactivity of crushed stones of various rock types using ASTM C 227 and C 1260, and compared the results of two test methods. This study also analyzed effects of particle size and grading of reactive aggregate on alkali-silica reaction expansion of mortar-bar. The effectiveness of mineral admixtures to reduce detrimental expansion caused by alkali-silica reaction was investigated through the ASTM C 1260 method. The mineral admixtures used were nv ash, silica fume, metakaolin and ground granulated blast furnace slag. The replacement ratios of 0, 5, 10, 15, 25 and $35\%$ were commonly applied for all the mineral admixtures and the replacement ratios of 45 and $55\%$ were additional applied for the admixtures that could maintain workability. The results indicate that replacement ratios of $25\%$ for ay ash, $10\%$ for silica fume, $25\%$ for metakaolin or $35\%$ for ground granulated blast furnace slag were most effective to reduce alkali-silica reaction expansion under the experimental conditions.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.4
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• pp.311-318
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• 2010

U. S. NRC Regulation Guide 1.52 regulating ESF ACS in nuclear power plants has been revised to revision 3. To apply reduction of operability test time, allowance of alternative challenge agents for in-place leak test of HEPA filters, and upgrade of Methyl Iodide penetration acceptance criterion in activated carbon performance test suggested in Reg. Guide 1.52(Rev.3) on Yonggwang units 5 and 6 ESF ACSes, technical feasibility study was carried out with on-site experiments as well as experiments with a lab-scale model. It was confirmed that the moisture in the system returned to the level before the test in 1 or 4 days even though the moisture was removed during the operability test lasting more than 10 hours. Therefore, it is appropriate to perform monthly operability test in 15 minutes just long enough to check the operability of equipment. To change challenge material for in-place HEPA filter leak test, size of aerosol, production rate, and leak detection capability were compared for DOP and PAO. It was concluded that PAO can be substituted for DOP in nuclear power plants. The upgrade of Methyl Iodide penetration acceptance criterion from 0.175 % to 0.5 % in active carbon filter bed deeper than 4 inches was to conform to the change of activated carbon performance test method to ASTM D3803(1989). It was confirmed that Methyl Iodide penetration acceptance criterion of 0.5 % under $30^{\circ}C$, relative humidity 95 % condition was conservatively good enough for testing performance of active carbon insitu. The licence change of Yonggwang units 5 and 6 has been completed based on this study.

• Applied Biological Chemistry
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• v.38 no.1
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• pp.55-62
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• 1995

To understand the molecular structure of Korean garlic viruses, cDNA cloning of virus genomic RNA was attempted. Virus particles were isolated from virus-infected garlic leaves and a cDNA library was constructed from garlic virus RNA. One of these clones, S81, selected by random sequencing has been identified as a member of potexvirus group other than potyvirus and carlavirus. The clone is 873 bp long contains most of the coat protein (CP) coding region and 3'-noncoding region including poly(A) tail. A putative polyadenylation signal sequence (AAUAAA) and the hexanucleotide motif (ACUUAA), a replicational cis-acting element conserved in the 3'-noncoding region of potexvirus RNAs are noticed. The clone S81 shows about 30-40% identity in both nucleotide and amino acid sequences with CPs of potexviruses. The genome size of the virus was analysed to be 7.46 knt by Northern blot analysis, which was longer than those of other potexviruses. The open reading frame encoding CP was expressed as a fusion protein (S81CP) in Escherichia coli and the recombinant protein was purified by immobilized metal binding affinity chromatography. Polyclonal antibody was raised against S81CP in rabbit to examine the occurrence of garlic potexvirus in Korean garlic plants by immunoblot analysis. Two virus protein bands of Mr 27,000 and 29,000 from garlic leaf extract of various cultivars reacted with the antibody. It was shown that Mr 27,000 band might not be a degradation product of Mr 29,000 band, suggesting that two types of potexvirus different in size of coat protein could exist in Korean garlic plants.

• Journal of Applied Biological Chemistry
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• v.57 no.1
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• pp.65-72
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• 2014

Biochar (BC) from biomass pyrolysis is a carbonaceous material that has been used to remove various contaminants in the environment. The eliminatory action for burcucumber (Sicyos angulatus L.) as an invasive plant is being consistently carried out because of its harmfulness and ecosystem disturbance. In this study, burcucumber biomass was converted into BCs at different pyrolysis temperatures of 300 and $700^{\circ}C$ under a limited oxygen condition. Produced BCs were characterized and investigated to ensure its efficiency on antibiotics' removal in water. The adsorption experiment was performed using two different types of antibiotics, tetracycline (TC) and sulfamethazine (SMZ). For the BC pyrolyzed at a high temperature ($700^{\circ}C$), the values of pH, electrical conductivity, and the contents of ash and carbon increased whereas the yield, mobile matter, molar ratios of H/C and O/C, and functional groups decreased. Results showed that the efficiency of BCs on antibiotics' removal increased as pyrolysis temperature increased from 300 to $700^{\circ}C$ (38 to 99% for TC and 6 to 35% for SMZ). The reaction of ${\pi}-{\pi}$ EDA (electron-donor-acceptor) might be involved in antibiotics' adsorption to BCs. BC has potential to be a superior antibiotics' adsorbent with environmental benefit by recycling of waste/invasive biomass.

• The Journal of the Petrological Society of Korea
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• v.16 no.3
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• pp.116-128
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• 2007

Detailed geological mapping, petrographic study, analyses of geochemistry and magnetic susceptibility, and K-Ar dating were carried out in order to determine the origin, age, and stratigraphic implications of granitic rock fragments in the pyroclastic rocks, SE Jinhae city, southern part of the Gyeongsang Basin. As a result, it was found that the area is composed of volcanics and tuffaceous sediments of the Yucheon Group, Bulguksa granites, pyroclastics bearing granitic rock fragments, $basalt{\sim}basaltic$ andesite, and rhyolite in ascending stratigraphic order. The granitic rock fragments in the pyroclastic rocks are divided into granodiorite and biotite granite, which have approximately the same characteristics as the granodiorite and the biotite granite of the Bulguksa granites, respectively, in and around the study area including color, grain size, mineral composition, texture (perthitic and micrographic textures), intensity of magnetic susceptibility (magnetite series), and geochemical features (calc-alkaline series and REE pattern). This leads to the conclusion that the rock fragments originated from the late Cretaceous Bulguksa granites abundantly distributed in and around the study area, but not from the basement rocks of the Yeongnam massif or the Jurassic granites. Based on relative and absolute ages of various rocks in the study area, the pyroclastics bearing granitic rock fragments are interpreted to have erupted between 52 and 16 Ma, i.e. during the Eocene and early Miocene. These results indicate that the various volcanisms, acidic to basic in composition, occurred after the intrusion of the Bulguksa granites, contrary to the general stratigraphy of the Gyeongsang Basin. Very detailed and cautious mapping together with relative and absolute age determinations are, thus, necessary in order to establish reliable stratigraphy of the Yucheon Group in other areas of the Gyeongsang Basin.

• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.687-693
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• 2006

The Stone Powder Sludge(below SPS) is the by-product from the process that translates stone power of 8mm under as crushed fine aggregate. It is the sludge as like cake that has average particle size of $7{\mu}m$, absorbing water content of 20 to 60%, and $SiO_2$ content of 60% over. Because of high water content of SPS, it is not only difficult to handle, transport, and recycle, but also makes worse the economical efficiency due to high energy consuming to drying. This study is aim to recycle SPS as it is without drying. Target product is the lightweight foamed concrete that is made from the slurry mixed with pulverized mineral compounds and foams through hydro-thermal reaction of CaO and $SiO_2$. Although in the commercial lightweight foamed concrete CaO source is the cement and $SiO_2$ source is high purity silica powder with $SiO_2$ of 90%, we tried to use the SPS as $SiO_2$ source. From the experiments with factors such as foam addition rate and replacement proportion of SPS, we find that the lightweight foamed concrete with SPS shows the same trends as the density and strength of lightweight foamed concrete increases according to decrease of foam addition rate. But in the same condition, the lightweight foamed concrete with SPS is superior strength and density to that with high purity silica. This trends is distinguished according to increase of replacement proportion of SPS, also the analysis of XRF shows that the hydro thermal reaction translates SPS to tobermorite. Although SPS has low $SiO_2$ contents, the lightweight foamed concrete with SPS has superior strength and density, because it reacts well with CaO due to extremely fine particles. We conclude that it is possible to replace the high purity silica as SPS in the lightweight foamed concrete experimentally.

• Korean journal of applied entomology
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• v.18 no.1 s.38
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• pp.1-10
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• 1979

An inclusion forming virus isolated from a fan webworm, Hyphantria cunea, in 1975 was identified as a nuclear polyhedrosis virus. With the virus isolated in Korea, it was considered that the virus would be one of the valuable microorganism in microbial control. In this connection, 1) the shape and size of the virus for identification, 2) susceptibility of the various instar larvae to the virus, 3) the effects of storage condition on the pathogenicity and the cross infection of the virus to the larvae of Bombyx mori were examined. The results are summarized as follows; 1. The polyhedron was tetrahedron or hexahedron of $2\mu$ in size and the rod-shaped virus particles consisting of $2\~14$ rods in a bundle were $330m{\mu}\times35m{\mu}$ in size. 2. The hexagonal nuclear polyhedra were found only in the nucleus of the midgut cells but were variable in size. 3. The $LD_{50}$ values for the various instar larvae of H. cunea were $8.377\times10^4\;PIBs/ml$ for the second, $4.974\times10^5\;PIBs/ml$ for the fifth instar larvae. The $LT_{50}values$ for $10^6\;PIBs/ml$ were 9.6 days for the second, 11.5 days for the third, 12.0 days for the fourth and 17 days for the fifth instar larvae. 4. The susceptibility of H. cunea to the nuclear polyhedrosis virus was greater in the first generation than in the second generation. 5. The effect of the storage conditions on the pathogenicity of the nuclear polyhedra was less in refrigerator $(5^{\circ}C)$ and in freezing $(-80^{\circ}C)$ than in room temperature $(18.5^{\circ}C)$, especially as air-dried polyhedra than as suspension. The pathogenicity of the polyhedra seemed to decrease by sunlight during storage as cadavers, since rather greater decrease in pathogenicity was found in sunny condition than in shady condition. 6. The effective spray concentration was $6.4\times10^7\;PIBs/ml$ in the field and its $LT_50$ values for the third and the fifth instar larvae were 4.8 days and 14.2 days, respectively. 7. No cross infections were found in the nuclear polyhedrosis virus between H. cunea and B. mori. larvae.