• Advances in concrete construction
• /
• v.16 no.3
• /
• pp.155-167
• /
• 2023

The penetrated chloride in concrete has different behavior with mix proportions and local exposure conditions, even in the same environments, so that it is very important to quantify surface chloride contents for durability design. As well known, the surface chloride content which is a key parameter like external loading in structural safety design increases with exposure period. In this study, concrete samples containing OPC (Ordinary Portland Cement), GGBFS (Ground Granulated Blast Furnace Slag), and FA (Fly Ash) had been exposed to submerged, tidal, and splash area for 5 years, then the surface chloride contents changing with exposure period were evaluated. The surface chloride contents were obtained from the chloride profile based on the Fick's 2nd Law, and the regression analysis for them was performed with exponential and square root function. After exposure period of 5 years in submerged and tidal area conditions, the surface chloride content of OPC concrete increased to 6.4 kg/m³ - 7.3 kg/m³, and the surface chloride content of GGBFS concrete was evaluated as 7.3 kg/m³ - 11.5 kg/m³. In the higher replacement ratio of GGBFS, the higher surface chloride contents were evaluated. The surface chloride content in FA concrete showed a range of 6.7 kg/m³ to 9.9 kg/m³, which was the intermediate level of OPC and GGBFS concrete. In the case of splash area, the surface chloride contents in all specimens were from 0.59 kg/m³ to 0.75 kg/m³, which was the lowest of all exposure conditions. Experimental constants available for durability design of chloride ingress were derived through regression analysis over exposure period. In the concrete with GGBFS replacement ratio of 50%, the increase rate of surface chloride contents decreased rapidly as the water to binder ratio increased.

• Nuclear Engineering and Technology
• /
• v.56 no.1
• /
• pp.257-264
• /
• 2024

The sodium cooled fast reactor (SFR) is one of the Gen-IV reactors with the most operating experience accumulated. Although the technology level is the most mature among the Gen-IV reactors, there is still a safety problem that has not been solved, which is the sodium-water reaction. Since sodium and water are separated only by a heat transfer tube with a thickness of only a few mm, there is inherently a risk of a sodium-water reaction (SWR) accident in the SFR. In this study, it is attempted to quantitatively evaluate the resistance of SWR accidents by replacing the shell and tube steam generator with printed circuit steam generator (PCSG) as a method to mitigate the SWR accident. To do this, a CATS-S (Compact Accident Tolerance Steam Generator-SWR) facility was designed and built. And for the quantitative evaluation of accident resistance, a methodology for measuring the impingement wastage rate was established. As a result of this research, the impingement wastage rate caused by SWR generated in a PCSG was measured first time. It was confirmed that the impingement wastage phenomenon was suppressed in the PCSG, and the accident resistance was higher than that of the SWR through comparison with the experimental results performed in the existing shell and tube steam generator. In conclusion, a PCSG is more resistant to impingement wastage as a result of the SWR accident than existing shell and tube steam generators, and it is estimated that a PCSG can mitigate SWR accidents, an inherent problem of SFR.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.26 no.6
• /
• pp.117-133
• /
• 2023

This study assessed the ecological health of border areas using the ecological health index and suggested Indicators for maintaining and promoting ecological values. We analyzed the change trends, pressures, and resilience of ecosystems and services in border areas, and identified their current status and sustainability. The main findings were: (1) ecological assets and ecosystem services in border areas could be compared through ecosystem health assessment; (2) it can be used to set priorities for management and conservation by identifying the relative importance and vulnerability of ecosystems and ecosystem services in each border area; and (3) the index presented in this study can be judged to have explanatory power for the characteristics of border areas and ecosystem health when compared to previous studies. Limitations of this study include the lack of literature and statistical data at the local government level and the resulting limited application of evaluation methods, which limited direct regional comparisons. To overcome the research limitations, further studies are needed, such as establishing ecological information in border areas, mapping and assessment of ecosystem services, and developing and applying assessments that reflect the opinions and participation of various stakeholders. This study was the first attempt to assess the health of ecosystems and ecosystem services in border areas and provided an important baseline for future changes in border areas. In the future, it will be helpful in national and local government policies and ecological assetecosystem management by supplementing insufficient information and presenting clear goals.

• Korean Journal of Environmental Agriculture
• /
• v.21 no.4
• /
• pp.237-242
• /
• 2002

A survey on four tributaries along with Mankyeong River was carried out to get the information far the water quality improvement and control. Typical paddy farming were major agricultural practices in Kosancheon and Soyangcheon. Iksancheon was livestock raising watershed. Chucheon was urban watershed. Water quality in six sites of main stream and four sites of tributaries in Mankyeong River were investigated from May to August in 2001. The concentration of nutrient in main stream of Mankyeong River were in the range of 3.78$\sim$12.68 mg/L for total nitrogen, 0.043$\sim$0.864 mg/L for total phosphorus, 2.59$\sim$13.29 mg/L for BOD and 12.9$\sim$119.5 mg/L for COD, respectively. Water quality of Mankyeong River mostly exceeded the standard water quality criteria of Korea. Major causes of water pollution were evaluated as sewage of swine and urban area. Among the four tributaries, water quality in agricultural practices, Kosancheon and Soyangcheon was relatively less polluted. While, the highest level of water pollution measured in Iksancheon was due to livestock. The water quality of Iksancheon and Chucheon was generally more polluted in the dry period than in rainy period.

• Science of Emotion and Sensibility
• /
• v.14 no.4
• /
• pp.513-524
• /
• 2011

Digital Technology actively utilized in all spheres by rapid changes in information and knowledge demands transformations not only in the sociocultural and educational spheres but also specifically in the field of arts education. Digital Technology becomes a challenging factor for the field of arts education. In this study purposed a new teaching-learning approach method in arts education, called "Music Technology-Based Learning"(hereafter, MTBL), which is to, first, take interdisciplinary approaches combining various subjects in the field of arts education. In the case study was conducted to examine the educational effects of the MTBL approach to the liberal arts course in university: mind maps derived from 2 sessions (pre-class and post-class), evaluation sheets regarding self-directed learning and in-depth interviews with ten voluntary learners after the class were used as methods for data collection. The result of case study shows positive changes in the terms of the degrees of emotional sensibilities of the learners. Moreover, the research confirmed the potential of MTBL as a new teaching and learning methodology in art education.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.8
• /
• pp.1133-1142
• /
• 2014

Interleukin-32 (IL-32) is a cytokine and inducer of various proinflammatory cytokines such as $TNF{\alpha}$, IL-$1{\beta}$, and IL-6 as well as chemokines. There are five splicing variants (${\alpha}$, ${\beta}$, ${\gamma}$, ${\delta}$, and ${\varepsilon}$) and IL-$32{\gamma}$ is the most active isoform. We generated human IL-$32{\gamma}$ transgenic (IL-$32{\gamma}$ TG) mice to express high level of IL-$32{\gamma}$ in various tissues, including immune cells. The pathology of sepsis is based on the systemic inflammatory response that is characterized by upregulating inflammatory cytokines in whole body, particularly in response to gram-negative bacteria. We investigated the role of IL-$32{\gamma}$ in a mouse model of experimental sepsis by using lipopolysaccharides (LPS). We found that IL-$32{\gamma}TG$ mice resisted LPS-induced lethal endotoxemia. IL-$32{\gamma}$ reduced systemic cytokines release after LPS administration but not the local immune response. IL-$32{\gamma}TG$ increased neutrophil influx into the initial foci of the primary injected site, and prolonged local cytokines and chemokines production. These results suggest that neutrophil recruitment in IL-$32{\gamma}TG$ occurred as a result of the local induction of chemokines but not the systemic inflammatory cytokine circulation. Together, our results suggest that IL-$32{\gamma}$ enhances an innate immune response against local infection but inhibits the spread of immune responses, leading to systemic immune disorder.

• Journal of Information Management
• /
• v.38 no.2
• /
• pp.153-173
• /
• 2007

[ $OntoFrame^{(R)}$ ] system provides information dissemination service and inference service, based on Semantic Web framework to fully support R&D activities. Although it is one of state-of-the-art systems in the viewpoint of functionality, we are not able to declare whether it has satisfiable usability because of the omission of usability test in development process. Thus, this research tries to reveal the usability level of the $OntoFrame^{(R)}$, and further to find ways to achieve a user-center system. Both 'theory-based assessment' by a software ergonomics expert and 'user test' by four users are used for evaluating the usability of the $OntoFrame^{(R)}$. We look forward this research to being a basic reference for practical systems aiming at satisfiable usability.

• Journal of Technology Innovation
• /
• v.29 no.3
• /
• pp.33-62
• /
• 2021

This study compares and analyzes the efficiency of R&D activities of technology-innovative small and medium-sized enterprises(SMEs) between industries and proposes ways to improve efficiency. The research samples are 6,708 technology-innovative SMEs, which have received a guarantee by the KIBO from 2008 to 2011. Input variables are the level of R&D personnel, R&D investment, and output variables are patent applications, prototype. Efficiency is measured by the DEA model, and indirect comparisons that are individually measured by industry are performed. As a result of the analysis, the CCR for determining the optimal returns to scale is 0.19, the BCC for determining the optimal input distribution is 0.70, and the SE for determining the optimal output is 0.30. By industry type, the medium and low-tech industries have high CCR and BCC, while the high-end and high-tech industries have high SE. R&D activities need to be operated on an optimal scale through managing R&D performance because there is the inefficiency of scale across the industry. The contribution of the study is to analyze the R&D efficiency of each industry of technology-innovative SMEs by the technology evaluation data of the KIBO.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.52 no.5
• /
• pp.445-451
• /
• 2019

In the industrial production of fish snacks using frozen surimi, molding the surimi mixture requires an expensive automated machine. This study investigated the efficacy of freeze molding without machinery molding in the production of Alaska pollock Theragra chalcogramma surimi snacks. At 90 minutes after deep freezing at $-80^{\circ}C$, the cutting ease and shape retention of the surimi mixture were superior. The freezing-molded surimi snack had a higher TVB-N (total volatile basic nitrogen) level (3.59 mg/100 g) than that (1.50 mg/100 g) of the normally molded surimi snack. Freezing did not affect the microstructure of the surimi snack or its hardness, which is an important physical property of snack products. The freezing-molded and normally molded snacks did not differ significantly in terms of color or appearance, or in any other aspect of the sensory evaluation. Our findings demonstrate that freeze molding does not induce changes in the quality of surimi snacks. Therefore, molding by freezing treatment could be used to produce surimi snacks at small- and mid-sized seafood companies.

• Korean Journal of Food Science and Technology
• /
• v.34 no.4
• /
• pp.617-624
• /
• 2002

Health drinks were prepared with freeze dried powder of 60% ethanol extract (60% EFDP), 60% ethanol extract after hydrolysis with amyloglucosidase (60% AEFDP) and 80% ethanol extract (80% EFDP) from roasted safflower seed. Quality characteristics and antioxidative properties were investigated. Yield of freeze dried powders were ranged in $4.67%{\sim}5.62%$. Brix, pH and titratable acidity of safflower drinks were ranged in $11.4{\sim}14.2%$, $2.83{\sim}3.34$ and $0.09{\sim}0.91%$, respectively. Content of total phenolic compounds was much more in 80% EFDP (117 mg/g) and safflower drink-I (SD-I, 440 ppm) than others. Content of total flavonoid was observed in higher level in 60% EFDP (49 mg/g) and safflower drink-V (SD-V, 138 ppm) than others. Antioxidant compounds such as N-[2-(5-hydroxy-1H-indol-3-yl)ethyl]ferulamide(serotonin-I) and N-[2-(5-hydroxy-1H-indol-3yl)ethyl]-p-coumaramide(serotonin-II) exhibited higher contents of 21.09 ppm, 33.56 ppm in 60% EFDP and of 3.83 ppm, 5.81 ppm in safflower drink-II (SD-II) than others. Content of acacetin was much more in 80% EFDP (13.53 ppm) and safflower drink-IV (SD-IV, 1.14 ppm) than others. From the DPPH test to measure antioxidant activity, it was shown that 80% EFDP and SD-I have stronger scavenging activities of 94.58% and 94.88%, respectively, while BHA standard solution does 93.88%. Among drinks, SD-II was revealed to have highest level on overall acceptance, color and flavor through sensory evaluation. These results induced that safflower seed can be used as natural antioxidant and functional food material.