• Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.16.1-16.8
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• 2016

To culture germline stem cells in vitro, establishment of the cell lines that can be used as the feeder cells is a prerequisite. In this study, we tried to establish gonad-derived cell lines in Siberian sturgeon (Acipenser baerii). Five 1-year-old A. baerii were used as a donor of gonad tissues, and gonad-dissociated cells were cultured in vitro. Subsequently, determination of growth conditions, long-term culture, characterization, and cryopreservation of the cell lines were also conducted. Five gonad-derived cell lines were stably established and cultured continuously over at least the 73th passage and 402 culture days under the media containing 20 % fetal bovine serum at $28^{\circ}C$. All cell lines consisted of two main cell types based on morphology even if the ratio of the two cell types was different depending on cell lines. Despite long-term culture, all cell lines maintained diploid DNA contents and expression of several genes that are known to express in the A. baerii gonad. After freezing and thawing of the cell lines, post-thaw cell viabilities between 57.6 and 92.9 % depending on cell lines were indentified, suggesting that stable cryopreservation is possible. The results and the cell lines established in this study will contribute to the development of an in vitro system for A. baerii germline stem cell culture.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.39-45
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• 2017

In this study, permeable repair materials mainly composed of silicate - based inorganic materials(SIM), which are easily available domestically, were prepared as a basic study for the development of permeable repair materials using SIM. SIM were compared and examined for their performance as repair materials by selecting a product group which has many cases of use in foreign countries. The SIM used were mainly composed of sodium, potassium and lithium silicate. Performance evaluation of SIM was performed by absorption and penetration, compression and adhesion, rapid chloride ion penetration, rapid freezing and thawing, and chemical resistance test. According to the test results, SIM showed effective performance in all areas, mainly because SIM permeates into the interior of the capillary and has a dense internal microstructure. Therefore, it can be used variously to improve the durability of concrete based on the results of this experiment.

• Clinical and Experimental Reproductive Medicine
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• v.21 no.1
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• pp.69-76
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• 1994

The survival and pregnancy rates were compared between non-frozen embryos and cryopreserved embryos at either pronucleate or 2-4 cell stages using the freezing and thawing techniques being identical in both groups were compared with fresh embryos. 496 embryos were frozen with 1, 2-propanediol and sucrose and 117 2-4 cell stages embryos had been thawed and 79.6 and 66.0% of them respectively were survival. Clinical pregnancy rate was 19.2% for embryos frozen at the pronucleate stage and 19.0% for embryos frozen at the 2-4 cell stages while the pregnancy rate of non-frozen embryos was 21.3%. There were no significant difference in the survival and pregnancy rates of embryos frozen at pronucleate and 2-4 cell stages. The current cumulative pregnancy rate per retrieval in all cycles with frozen zygotes is 35.4 %, consid~ erably higher than observed in single transfers of embryos without cryopreservation(21.3%); predicted pregnancy rate after transfer of all frozen embryos is 43.3 %. It is concluded that firstly, the survival and pregnancy rate of cryopreserved embryos at pronucleate or 2-4 cell stages are very similar to those from their fresh embryos and non-frozen embryos and secondly, cryopreservation substantially enhances pregnancy attainment from in vitro fertilization.

• Journal of Korean Tunnelling and Underground Space Association
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• v.8 no.2
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• pp.165-182
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• 2006

In this study, field test was performed to investigate the strength-improvement effect of shotcrete mixed Micro-silica fume and shotcrete quality was estimated by EFNARC standard. Deterioration test combined the Freezing-thawing and Carbonation was also performed in order to investigate a long-term durability of high-strength shotcrete. As a result of test, the compressive strength of shotcrete using Micro-silica fume was 45.2~55.8MPa and flexible strength was 5.01~6.66MPa, so a promotion ratio of strength was 37~79%, 17~61% respectively. And the strength-improvement effect of strength by silica fume addition ratio of 7.5~10% for cement mass was more superior to the others. Due to relative dynamic modulus, mass decrease rate and carbonation progress of shotcrete mixed Micro-silica fume, it was especially realized that Micro-silica fume reduced deterioration caused by steel fiber and improved a long-term durability of shotcrete.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1242-1248
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• 2005

This study was designed to investigate the in vitro developmental ability and apoptosis of bovine embryos nucleartransferred (NT) with frozen-thawed or cooled donor cells. Cultured adult bovine ear cells were used as donor cells after sub-culturing to confluence (CC), cooling to 4$^{\circ}C$ for 48 h, or freezing-thawing (FT). Apoptotic cells in blastocysts were evaluated for apoptosis by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) method. Fusion, cleavage and blastocyst rates were 69.0 (167/242), 68.8 (115/167), and 29.9 (50/167) with CC cells, 70.4 (88/125), 69.3 (61/88), and 29.6 (26/88) with cooled cells and 66.1 (117/177), 70.1 (82/117), and 13.7 (16/117) with FT cells, respectively. Blastocyst rates of NT embryos derived from FT cells were significantly lower than those from CC or cooled cells (p<0.05). In addition, NT blastocysts produced by using FT cells showed significantly higher apoptosis rates (6.4${\pm}$4.0%) than those produced by CC (2.8${\pm}$1.7%) or cooled (2.3${\pm}$1.3%) cells. However, cooling of donor cells had no significant adverse effect on blastocyst rate as well as apoptosis rate. Therefore, our results suggest that cooled cells may be used as an alternative to freshly cultured confluent culture cells, as donor cells, for the production of Somatic nuclear cloned cattle.

• Tunnel and Underground Space
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• v.21 no.2
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• pp.145-150
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• 2011

Variations of physical properties such as weight loss rate, wave velocity and uniaxial compressive strength after performing freeze-thaw cyclic test were measured in order to define weathering characteristics of sandstone and andesite. Weight change in specimens of the two rocks decreased with increasing the repetition number of freeze-thaw cyclic test. In particular, weight loss of andesite specimens was very irregular. P-wave velocity of sandstone specimens decreased more than 5%. On the other hand, P-wave velocity of andesite specimens do not vary up to 500 cycles and decreased more than 5% after 1000 cycles. This implies that the sandstone are easily weakened and loosened by weathering processes, while the andesite are relatively strong. In addition, the wave velocity changes of the andesite specimens coincident with the weight change. Uniaxial compressive strengths of the sandstone specimens slightly decreased at the early stage of the freezing-thawing cyclic test, then tended to be irregular after 64 cycles. In conclusion, the rock specimens showed smaller weight loss, less had lower strength reduction rate.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.394-400
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• 1998

Cryopreservation of embryos by vitrification is a simple method to preserve bovine embryos for subsequent embryo transfer, but embryonic viability after vitrification has been inconsistent and low compared with conventional slow freezing. The aim of the present study is to examine the effect of serum or serum albumin in a vitrification solution and epidermal growth factor(EGF) or fibroblast growth factor(FGF) on in vitro viability of bovine blastocysts frozen by vitrification. Bovine blastocysts were produced by in vitro maturation, fertilization of follicular oocytes and culture of embryos in a synthetic oviduct fluid medium(SOFM) containing BSA and 19 essential and nonessential amino acids. Blastocysts with excellent or good morphology were selected at 7 or 8 days after culture and utilized for vitrification. In experiment 1, blastocysts were vitrified in a solution containing semi-fetal calf serum(SFCS) or BSA(5 or 10mg/ml) and then their subsequent viabilities were examined by culturing thawed embryos in a SOFM containing BSA and 19 amino acids. Effect of EGF or FGF added to a SOFM containing polyvinyl alcohol(PVA) on the viability of vitrified-thawed blastocysts was investigated in experiment 2. BSA added at 5 or 10mg/ml to a vitrification solution showed significantly higher(p < 0.05) developmental rate to expanded and hatching blastocysts than SFCS, but there was no significant difference in the developmental rate to hatched blastocysts after thawing. Supplementation of a culture medium with EGF and/or FGF significantly increased(p < 0.05) embryo development to expanded blastocysts compared with control but showed no beneficial effect on the development to hatching or hatched blastocysts. Coculture of thawed embryos with granulosa cells in a TCM 199 containing 10% fetal calf serum(FCS) showed the highest developmental rate to expanded, hatching and hatched blastocysts among the groups tested. In conclusion, supplementation of a vitrification solution with BSA at 5mg/ml and culture of thawed blastocysts in a medium containing EGF and/or FGF can improve in vitro viability of bovine blastocysts frozen by vitrification.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.4
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• pp.1095-1104
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• 2014

This paper presents the results of experimental work on both strength characteristics and durability of concrete or mortar having 50% ground granulate blastfurnace slag(GBS) with different fineness levels (4,450, 6,000 and $8,000cm^2/g$). Compressive and split tensile strength test results indicated that the concrete with a higher fineness level of GBS exhibited a better strength development due to the acceleration of latent hydraulic property at the later curing stage compared with ordinary portland cement concrete. Meanwhile, it was found that a higher fineness level of GBS showed some negative effects on the resistance against freezing-thawing action. However, incorporation of GBS to concrete, irrespective of fineness levels, significantly enhanced the chloride ions penetration resistance. The resistance against sulfate attack of mortar with GBS was greatly dependent on the attacking sources from sulfate environments.

• Journal of the Mineralogical Society of Korea
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• v.17 no.1
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• pp.23-35
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• 2004

The weathering characteristics of periodically submerged sedimentary rocks in the Sayeon dam, Ulsan was examined by field work, electron probe micro-analysis, X-ray diffraction, and X-ray fluorescence spectrometry. Analysis of fracture zone and exfoliation showed the submerged sedimentary rocks have undergone severe mechanical weathering. Mechanical weathering in the water-rock interface accelerated chemical weathering, such as dissolution and alteration of the most of minerals except for quartz in the weathering zone. The dissolution of carbonates specially calcite, is remarkable creating the cavities, whereas formation of minerals including clay minerals is not active. The sedimentary rocks have been periodically submerged for a certain period of time, and have repeated freezing and thawing. This mechanical weathering favored infiltration, which accelerated mineral dissolution. The high content of easily soluble carbonate of the sedimentary rocks is likely the major cause of intense chemical weathering. The dissolved elements within the infiltrated water interrupted the occurrence of clay and weathering minerals, and expend fractures by infiltrated water accelerated weathering process.

• Journal of the Korean Geotechnical Society
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• v.27 no.5
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• pp.61-74
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• 2011

This is a fundamental research on use as fill material of lightweight waste such as bottom ash and tire shred. We carried out the test for particle size distribution, specific gravity, density, shear strength, permeability and vertical compression settlement, considering water content change and temperature effect of several waste materials. Bottom ash, which is lighter than soils, has similar permeability and particle size distribution to those of weathered soils. But permeability may differ depending on the particle size distribution. The shear strength aspect of bottom ash and tire shred mixed materials are similar to that of natural fill materials. In the 1-D vertical compression settlement test, we could be assured that bottom ash and tire shred mixed materials showed similar compression settlement to that of sand under actual vertical stress. Furthermore, materials including bottom ash showed smaller compression settlement than that of weathered soils in the long-term settlement test under wetting and freezing-thawing condition.