• Journal of Powder Materials
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• v.24 no.2
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• pp.133-140
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• 2017

This study investigates the oxidation properties of Fe-14Cr ferritic oxide-dispersion-strengthened (ODS) steel at various high temperatures (900, 1000, and $1100^{\circ}C$ for 24 h). The initial microstructure shows that no clear structural change occurs even under high-temperature heat treatment, and the average measured grain size is 0.4 and $1.1{\mu}m$ for the as-fabricated and heat-treated specimens, respectively. Y-Ti-O nanoclusters 10-50 nm in size are observed. High-temperature oxidation results show that the weight increases by 0.27 and $0.29mg/cm^2$ for the as-fabricated and heat-treated ($900^{\circ}C$) specimens, and by 0.47 and $0.50mg/cm^2$ for the as-fabricated and heat-treated ($1000^{\circ}C$) specimens, respectively. Further, after 24 h oxidation tests, the weight increases by 56.50 and $100.60mg/cm^2$ for the as-fabricated and heat-treated ($1100^{\circ}C$) specimens, respectively; the latter increase is approximately 100 times higher than that at $1000^{\circ}C$. Observation of the surface after the oxidation test shows that $Cr_2O_3$ is the main oxide on a specimen tested at $1000^{\circ}C$, whereas $Fe_2O_3$ and $Fe_3O_4$ phases also form on a specimen tested at $1100^{\circ}C$, where the weight increases rapidly. The high-temperature oxidation behavior of Fe-14Cr ODS steel is confirmed to be dominated by changes in the $Cr_2O_3$ layer and generation of Fe-based oxides through evaporation.

• The Journal of Engineering Geology
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• v.22 no.2
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• pp.233-241
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• 2012

The objectives of this study were to test geothermal conductivity (k), water velocity, water quantity, and pipe pressure from a ground heat exchanger in the field, and then to analyze these data in relation to the effectiveness and economical efficiency for application of geothermal energy. After installation of the apparatus required for field tests, geothermal conductivity values were obtained from three different cases (second, third, and fourth). The k values of the second case (506 m depth) and third case (151 m depth) are approximately 2.9 and 2.8, respectively. The k value of the fourth case (506 m depth, double pipe) is 2.5, which is similar to the second and third cases. This result indicates that hole depth is a critical factor for geothermal applications. Analysis of the field data (k, water velocity, water quantity, and pipe pressure) reveals that a single geothermal system at 506 m depth is more economically efficient than three geothermal systems at depths intervals of 151 m. Although it is more expensive to install a geothermal system at 506 m depth than at 151 m depth, test results showed that the geothermal system of the fourth case (506 m, double pipe) is more economically efficient than the system at 151 m depth. Considering the optional cost of maintenance, which is a non-operational expense, the geothermal system of the fourth case is economically efficient. Large cities and areas with high land prices should make greater use of geothermal energy.

• Horticultural Science & Technology
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• v.34 no.6
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• pp.912-923
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• 2016

Watermelon production is often limited by powdery mildew in areas with a large daily temperature range. Development of resistant watermelon cultivars can protect against powdery mildew; however, little is known about the characteristics of its causal agents. Here, we identified the genus and race of a causal pathogen of powdery mildew in Ansung province of South Korea, and developed molecular markers for the generation of resistant watermelon cultivars. The causal pathogen was determined to be Podosphaera xanthii based on multiple sequence alignments of internal transcribed spacers (ITS) of rDNA. The physiological race was identified as 1W, and the Ansung isolate was named P. xanthii 1W-AN. Following inoculation with the identified P. xanthii 1W-AN, we found inheritance of the resistant gene fitting a single dominant Mendelian model in a segregated population ('SBA' ${\times}$ PI 254744). To develop molecular markers linked to fungus-resistant loci, random amplified polymorphic DNA (RAPD) was accomplished between DNA pooled from eight near-isogenic lines (NILs; $BC_4F_6$), originated from PI 254744 and susceptible 'SBB' watermelon. After sequencing bands from RAPD were identified in all eight NILs and PI254744, 42 sequence-characterized amplifiedregion (SCAR) markers were developed. Overall, 107 $F_2$ plants derived from $BC_4F_6$ NIL-1 ${\times}$ 'SBB' were tested, and one SCAR marker was selected. Sequence comparison between the SCAR marker and the reference watermelon genome identified three Nco I restriction enzyme sites harboring a single nucleotide polymorphism, and codominant cleavage-amplified polymorphic site markers were subsequently developed. A CAPS marker was converted to a high-resolution melt (HRM) marker, which can discriminate C/T SNP (254PMR-HRM3). The 254PMR-HRM3 marker was evaluated in 138 $F_{2:3}$ plants of a segregating population ('SBA' ${\times}$ PI254744) and was presumed to be 4.3 cM from the resistance locus. These results could ensure P. xanthii 1W-AN resistance in watermelon germplasm and aid watermelon cultivar development in marker-assist breeding programs.

• Ecology and Resilient Infrastructure
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• v.6 no.4
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• pp.236-242
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• 2019

In this study, we developed the system that can collect and store environmental disaster data into the database and use it for environmental disaster management by converting structured and unstructured documents such as images into electronic documents. In the 4th Industrial Revolution, various intelligent technologies have been developed in many fields. Environmental disaster information is one of important elements of disaster cycle. Environment disaster information management refers to the act of managing and processing electronic data about disaster cycle. However, these information are mainly managed in the structured and unstructured form of reports. It is necessary to manage unstructured data for disaster information. In this paper, the intelligent generation approach is used to convert handout into electronic documents. Following that, the converted disaster data is organized into the disaster code system as disaster information. Those data are stored into the disaster database system. These converted structured data is managed in a standardized disaster information form connected with the disaster code system. The disaster code system is covered that the structured information is stored and retrieve on entire disaster cycle. The expected effect of this research will be able to apply it to smart environmental disaster management and decision making by combining artificial intelligence technologies and historical big data.

• Journal of the Korean Ceramic Society
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• v.38 no.9
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• pp.799-805
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• 2001

Two commercial alumina powders having different particle size of $0.5{\mu}m$ and 3${\mu}$m were presintered at 1120$^{\circ}$C for 2h and then lanthanum aluminosilicate glass was infiltrated at 1100$^{\circ}$C for up to 4h to obtain the densified glass-alumina composites. The effect of alumina particle size on packing factor, microstructure, wetting, porosity and pore size, and mechanical properties of the composite was investigated. The optimum mechanical properties and compaction behavior were observed for the 3${\mu}$m alumina particle dispersed composite. The 3${\mu}$m alumina particle size and distribution for he preform were within 0.1 to 48${\mu}$m and bimodal and random orientation. The strength and the fracture toughness of the composite having 3${\mu}$m alumina particles were 519MPa and $4.5MPa{\cdot}m^{1/2}$, respectively.

• The Journal of the Korea Contents Association
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• v.20 no.3
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• pp.645-660
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• 2020

This study attempts to look at the role that modern Christianity should play on an educational level in order to effectively prepare for the future society in the era of the fourth industrial revolution. In the coming era, various areas of human life, including human labor, are expected to be replaced by AI robots. As new alternatives, the ability to empathize effectively and educate creatively to help develop personality qualities are proposed in a rapidly changing world of uncertainty. Modern Christianity, however, has the responsibility to help solve the problems facing this era in the public as a member of the community beyond the boundaries of the church. The purpose of this study is to examine what education the modern Christianity can present to the world as a public discourse and how that should be done. This study suggests the following points on the proper education for which Christianity will participate in the era of the fourth industrial revolution. First, it is necessary to emphasize a sense of belonging through a sense of community. Second, serious considerations and preparations for education that develops creativity are needed. Third, it is necessary to establish an educational direction that encompasses the entire generation. Fourth, practical education through digital utilization should be implemented in the local community. Finally, Christianity in the era of the fourth Industrial Revolution needs to be more integrated. As the Christian community recognizes that the agenda of the community is its task, it will be able to create a co-existing and symbiotic society.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.3
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• pp.382-388
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• 2010

This study was aimed to examine the quality characteristics of the bread with the muffin added with the by-product of fermented ethanol from wheat rye that has high $\beta$-glucan contents. In the muffin added with TEFB (Triticale Ethanol Fermentation By-product), the height of the muffin decreased as the additive contents increased. There was no significant difference among the volumes of the muffins added with TEFB 0%, 5%, 10% and 15%. In the muffin added with TEFB, the height of the muffin decreased as the additive contents increased. In the moisture measurement of TEFB muffin, the moisture contents increased as the TEFB additive contents increased. Using SEM, showed that as TEFB additive contents increased, gluten contents was relatively lowered, which led to the reduced gas retention power and generation of rough tissues. In chromaticity, as the TEFB additive contents increased, the brightness decreased and the redness and yellowness decreased as well. The result of texture measurement showed that as the TEFB additive contents increased, hardness increased. springiness decreased gradually as the TEFB additive contents increased. There was no significant difference in cohesiveness (p<0.005). Although there as signigicant difference between the control group and the additive group in gumminess (p<0.005), there was no significant difference for a certain amount of additive contents (p<0.05). While there was significant difference in chewiness between the control group and the additive group (p<0.05). there was no significant difference for a certain amount of additive contents (p<0.05). The result of taste test of TEFB added muffin showed that the preference for the muffins added with 5% or more TEFB decreased. This study found that more than 5% of TEFB additives to muffin decreases the preference level.

• Clean Technology
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• v.26 no.2
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• pp.91-95
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• 2020

A new eco-friendly synthetic method for N-hydroxysuccinimide (NHS), widely used in the pharmaceutical and fine chemical industries, is developed. Conventional synthesis method yields NHS of about 70% after its reaction with NH₂OH to succinic acid. In this method, NHS can be obtained using low-cost succinic acid, but a great deal of solvents are required as an extraction method to purify NHS, while the work-up process is complicated, resulting in low yield. In addition, there is a safety risk due to the high reaction temperature for commercial production, and it is not economical due to the high cost of production from the generation of much waste because of an acid catalyst and the use of various solvents. In order to make up for this shortcoming, this study used succinic anhydride as a raw material under low temperature reaction and developed a new eco-friendly industrial synthesis method using isobutyl alcohol for a single solvent and non-catalytic reaction. The economic evaluation confirms that there is a cost reduction effect of about 20%. In the future, based on this result, studies may establish a commercial production technology through scale-up research and proceed with foreign technology transfer.

• Korean Journal of Poultry Science
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• v.34 no.4
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• pp.287-294
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• 2007

Current study was conducted to identify the effects of dietary supplementation of Aspergillus oryzae ferments (AOF) cultured under normal (NAOF) or nitrogen-deficient (NMAOF) environment on feed efficiency, nutrient digestibility for broiler chicks. Fecal microbes and ammonia gas production were also determined. A total of 168 male Avian chicks, 2-wk-old, were randomly assigned into 56 cages, three chicks per cage. There were seven treatments (Control, NAOF 0.05, 0.1, 0.5%, NMAOF 0.05, 0.1, 0.5%), with 8 replicates (cages) per treatment. There was no significant difference in nutrient digestibility between two AOF groups, but the digestibility was greatly(p<0.05) improved by AOF supplementation. Total microbial account significantly (p<0.05) differed between the treatment groups with the highest number for NNAOF, followed by NAOF and control. In the case of Escherichia coli and Salmonella, the AOF supplementation significantly (p<0.05) reduced their numbers in feces, with a particular reduction in NNAOF group. Levels of ammonia gas generation were in order of control>NAOP>NNAOP. The current data implied that AOF supplementation, particularly grown under nitrogen-deficient environment, would be a feasible way to improve feed efficiency for broiler production, as well as to reduce environmental cost. However, further studies remain for industrial application.

• Journal of Life Science
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• v.23 no.10
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• pp.1223-1229
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• 2013

Ursolic acid (UA) a bio-active ingredient found in a variety of fruits and vegetables, and it has potent antioxidant activity. However, the role of UA in mouse embryonic stem (ES) cells is poorly understood. This study investigated the functional role of UA in regulating the development of mouse ES cells under hypoxia. Hypoxia did not exert a significant effect on the undifferentiated state of mouse ES cells. However, it induced reactive oxygen species (ROS) generation and increased the level of lactate dehydrogenase (LDH) production at 48 h of hypoxic exposure. Conversely, oxidative stress induced by hypoxia was significantly inhibited by UA ($30{\mu}M$) pretreatment. Hypoxia significantly decreased cell survival and the level of [$^3H$] thymidine incorporation, both of which recovered following pretreatment of UA. In addition, UA decreased the apoptotic effect of hypoxia by attenuating caspase-3 cleavage or by recovering cellular inhibition of the apoptotic protein (cIAP)-2 and Bcl-2 expression. We further found that UA decreased senescence-associated beta-galactosidase activity. We suggest that UA is a natural antioxidant and one of the functional modulators of hypoxia-induced survival, apoptosis, proliferation, and aging in mouse ES cells.