• Journal of Korean Society of Disaster and Security
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• v.17 no.1
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• pp.27-35
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• 2024

This paper presents experimental research results to evaluate the applicability of chemical neutralization reaction and ultrasonic wave to remove cement paste and mortar attached to the surface of recycled aggregate. In order to derive optimal ultrasonic cleaning efficiency and chemical neutralization reaction, experiments were conducted using variables such as ultrasonic frequency and type of chemical solution. As a result, the optimal frequency was found to be 24 kHz, and immersion in a 15% hydrochloric acid solution for 30 minutes of stimulation showed the highest efficiency. In addition, the specific gravity, absorption rate, and wear rate of the quality-improved recycled coarse aggregate were similar to those of general aggregate and were found to satisfy all KS F 2527 standards. Therefore, it is believed that the recycled aggregate whose quality has been improved through the method proposed in this study can be used for concrete.

• Journal of Microbiology and Biotechnology
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• v.34 no.4
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• pp.846-853
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• 2024

Adzuki bean (Vigna angularis), which provides plant-based proteins and functional substances, requires a long soaking time during processing, which limits its usefulness to industries and consumers. To improve this, ultrasonic treatment using high pressure and shear force was judged to be an appropriate pretreatment method. This study aimed to determine the optimal conditions of ultrasound treatment for the improved hydration of adzuki beans using the response surface methodology (RSM). Independent variables chosen to regulate the hydration process of the adzuki beans were the soaking time (2-14 h, X₁), treatment intensity (150-750 W, X₂), and treatment time (1-10 min, X₃). Dependent variables chosen to assess the differences in the beans post-immersion were moisture content, water activity, and hardness. The optimal conditions for treatment deduced through RSM were a soaking time of 12.9 h, treatment intensity of 600 W, and treatment time of 8.65 min. In this optimal condition, the values predicted for the dependent variables were a moisture content of 58.32%, water activity of 0.9979 a_w, and hardness of 14.63 N. Upon experimentation, the results obtained were a moisture content of 58.28 ± 0.56%, water activity of 0.9885 ± 0.0040 a_w, and hardness of 13.01 ± 2.82 g, confirming results similar to the predicted values. Proper ultrasound treatment caused cracks in the hilum, which greatly affects the water absorption of adzuki beans, accelerating the rate of hydration. These results are expected to help determine economically efficient processing conditions for specific purposes, in addition to solving industrial problems associated with the low hydration rate of adzuki beans.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.2
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• pp.183-193
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• 2018

Currently, the Korea Atomic Energy Research Institute (KAERI) is planning to build the Ki-Jang Research Reactor (KJRR) in Ki-Jang, Busan. It is important to safely dispose of low-level radioactive waste from the operation of the reactor. The most efficient way to treat radioactive waste is cement solidification. For a radioactive waste disposal facility, cement solidification is performed based on specific waste acceptance criteria such as compressive strength, free-standing water, immersion and leaching tests. Above all, the leaching test is important to final disposal. The leakage of radioactive waste such as $^{137}Cs$ causes not only regional problems but also serious global ones. The cement solidification method is simple, and cheaper than other solidification methods, but has a lower leaching resistance. Thus, this study was focused on the development of cement solidification for an enhancement of cesium leaching resistance. We used Zeolite and Loess to improve the cesium leaching resistance of KJRR cement solidification containing simulated KJRR liquid waste. Based on an SEM-EDS spectrum analysis, we confirmed that Zeolite and Loess successfully isolated KJRR cement solidification. A leaching test was carried out according to the ANS 16.1 test method. The ANS 16.1 test is performed to analyze cesium ion concentration in leachate of KJRR cement for 90 days. Thus, a leaching test was carried out using simulated KJRR liquid waste containing $3000mg{\cdot}L^{-1}$ of cesium for 90 days. KJRR cement solidification with Zeolite and Loess led to cesium leaching resistance values that were 27.90% and 21.08% higher than the control values. In addition, in several tests such as free-standing water, compressive strength, immersion, and leaching tests, all KJRR cement solidification met the waste acceptance or satisfied the waste acceptance criteria for final disposal.

• Journal of Venture Innovation
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• v.5 no.4
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• pp.135-156
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• 2022

This study attempted to identify the factors affecting entrepreneurial intention and to confirm the moderating effect of social support that plays a positive role in increasing entrepreneurial intention. The subjects of the study were 419 ordinary people, and data were obtained online and analyzed. The analysis method of this study was based on the SPSS statistical program Ver. 24, and a hierarchical regression analysis method was conducted to analyze the moderating effect. The results of hypothesis verification analysis in this study are as follows. First, innovativeness, risk-taking, self-fulfillment, economic motivation, immersion in a drama, drama role model, and indirect experience, all had a significant positive(+) effect on entrepreneurial intention. Second, among the factors affecting entrepreneurial intention, self-fulfillment was found to have the greatest influence. Third, it was confirmed that the moderating effect of social support between various variables and entrepreneurial intention had a significant effect on innovativeness, self-fulfillment, drama role model, and indirect experience, and entrepreneurial intention. The academic value of this study is to confirm the effect of drama characteristic variables on entrepreneurial intention. In addition, it was possible to confirm the moderating effect of social support, which is the total of individual external support. The implication of this study is that the desire for achievement had the greatest influence on entrepreneurial intention. Therefore, it is necessary to develop a desire to achieve in start-up support policies and start-up education. In addition, in light of the ripple effect of TV dramas, drama role model and indirect experience increase entrepreneurial intention, so it was possible to predict its influence on changes in perception of start-ups and entrepreneurs.

• The Korean Journal of Physiology
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• v.8 no.2
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• pp.67-74
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• 1974

The object of this research is aimed to determine the activity of adenyl cyclase in both skeletal muscle sarcolemma and fat cell ghost of epididymal adipose tissue isolated from rats exposed to cold for various length of time in an attempt to evaluate whether the tissue sensitivity to catecholamine is increased when rats are exposed to cold for long periods of time Methods: a)Animals: Albino rats ranging in weight from 150 to 200 gm were used throughout this study. For experimental purposes, the rats are divided into two groups: experimental animals were place4 in a cold room at $4^{\circ}C$, controls being kept at $25^{\circ}C$. At the end of 2, 4, 6, 12, and 16 weeks. exposure to cold the rats were used to measure the adenyl cyclase activity. b) Isolation of plasma membrane from skeletal muscle and adipose tissue: The Plasma membrane of skeletal muscle from hind limbs of rats are prepared by the method employed by Rosenthal et at. and fat cell ghost of epididymal adipose tissue of rats by the method employed by Rodbell. c) Adenyl cyclase assay: Adenyl cyclase activity were measured by the method employed by Marinetti et al. Briefly, plasma membrane was incubated with $3^H-ATP$, various amount of noradrenaline and other incubation mixture at $37^{\circ}C$ for 20 minutes. After stopping the enzyme reaction by immersion in boiling water, carrier 3',5'-AMP was added to the system as a marker and $100\;{\mu}1$ aliquots of incubation mixture were pipetted on $20{\time}20$ Whatman No. 3 MM filter paper for one dimensional chromatography. The cyclic AMP spots were cut off and placed in counting vials containing 10ml of Bray's scintillation cocktail. Radioactivity was determined with a Packard Tri-Carb liquid scintillation counter. The enzyme activity is expressed as nanomoles of cyclic AMP produced per mg of membrane per hour. Result: 1. Average adenyl cyclase activity in the plasma membrane of skeletal muscle before and after noradrenaline administration was significantly higher in the cold-exposed rats as compared to the control. Continuous exposure to cold Produced an increased adenyl cyclase activity before and after noradrenaline administration. Adenyl cyclase activity reached peak levels at the 6 weeks exposure to told and level of adenyl cyclase activity remained high. Noradrenaline administration to the incubation medium induced a significant increase in adenyl cyclase activity and the degree of stimulation were proportional to the hormonal concentration But the rate of inclement in adenyl cyclase activity by noradreasline was the same in both groups. 2. Adenyl cyclase activity in fat cell ghost between cold exposed and control rats showed no significant differences before and after noradreualine administration. In summary, it can be concluded that cold adaptation give rise an increased activity of adenyl cyclase in plasma membrane of skeletal muscle in rats.

• The Journal of Industrial Distribution & Business
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• v.10 no.3
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• pp.73-83
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• 2019

Purpose - This study is to clarify the structural relationship between the direct supervisor and organizational commitment and organizational citizenship behavior through mediation of the Leader-member exchange (LMX) in the hospital organization, and to confirm the mediating effect of the LMX. Through this study, we will provide basic data on the aspects of HR to enhance organizational immersion and organizational civic behavior in hospital organizations, and present suggestions on academic contribution and effective organizational operation measures. Research design, data, and methodology - This study is to investigate the relationship between authentic leadership and OC and OCB of the organization member, which is proposed to secure more active and high competitiveness in the recent changing medical environment, with multi-regression and B&K(1986) method. For this purpose, 653 employees of senior hospitals in Seoul and Kyeong-In area were surveyed using structured questionnaires. Each questionnaire was composed of 7-point scale, and each hypothesis was testified by multiple leaner regression and by BK method for testifying mediator effect. Result - As a result of the analysis, it was found that the male and non-medical staff had higher recognition level than the medical staff in the LMX, organizational commitment and organizational citizenship behavior. In the senior management or more than 5 years' experience group, organizational commitment and organizational citizenship behavior were recognized higher than the group of subordinate managers. Second, authentic leadership has a positive influence on LMX, organizational commitment and organizational citizenship behavior, and LMX has a significant positive impact on organizational commitment and organizational citizenship behavior. In addition, as a result of analyzing LMX mediating effect in the relationship of authentic leadership and organizational effectiveness by BK method, LMX had partial mediating effects between authentic leadership and organizational citizenship behavior, and between authentic leadership and organizational commitment. Conclusion - Results of the study confirmed that all the members of the hospital organization that were lacking served as positive factors for the relationships of authentic leadership and LMX, and authentic leadership and organizational effectiveness. It is expected that the hospital organization will be able to suggest such as the organizational approach to expect high organizational effectiveness centering on authentic leadership ability as psychological capital.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.16-23
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• 2018

In this study, Polydimethylsiloxane (PDMS) was applied to Strain Hardening Cement Composites (SHCC) for penetrating water repellency. The penetration depth of PDMS, strength of SHCC, and chloride ion penetration resistance of SHCC were investigated. As a result of measuring penetration depth of PDMS when applying different application method, it was confirmed that all methods satisfied the requirements of KS F 4930. Although the immersion method showed the largest penetration depth, the spray method was considered to be more appropriate considering the ease of field application. Compressive strength tests showed that the penetration depth of PDMS decreased as the compressive strength of SHCC increased. The compressive strength of M4-A and M4-B specimens with large PDMS penetration depths decreased by 9.6% and 8.0%, respectively, compared with those of M4 specimens produced without PDMS. Compressive strengths of the M1-A and M1-B specimens with small PDMS penetration depths were reduced by 4% and 2.2%, respectively, compared with the M1 specimen. As a result, it can be seen that the strength reduction rate of SHCC increases as the penetration depth of PDMS increases. The chlorine ion penetration tests showed that the chlorine ion penetration resistance increases with the penetration depth of PDMS.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.32 no.5
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• pp.183-190
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• 2022

Diopside (CaMgSi₂O₆) is known to have high bioactivity as well as excellent mechanical properties. In this study, we tried to improve the bioactivity of zirconia ceramics by surface coating of diopside and its bioactivity was investigated through an in vitro test. Surface coating on zirconia substrate was prepared by sol-gel method using a diopside sol which was prepared by dissolving Ca(NO₃)₂·4H₂O, MgCl₂·6H₂O and Si(OC₂H₅)₄ in ethanol with a fixed molar ratio and then hydrolysis. To examine the bioactivity of diopside coating, we examined the surface dissolution and the precipitation of new hydroxyapatite particles through in vitro test in SBF (Simulated Body Fluid) solution. Dense and thick diopside coating layers could be fabricated on zirconia substrate by sol-gel method. Also, we confirmed that they contained high bioactivity from the in vitro test, indicated the precipitation of hydroxyapatite particles after the 14 days immersion in SBF solution. In addition, we checked that the bioactivity of diopside coated layers was dependent on the repeated coating cycle and coating thickness.

• Journal of fish pathology
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• v.35 no.1
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• pp.113-120
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• 2022

Scuticociliatosis caused by Miamiensis avidus is a very important parasitic disease in olive flounder farming industry. The aim of this study was to determine effect of combined treatment with blue LED (light-emitting diode) illumination and formalin on olive flounder (Paralichthys olivaceus) infected with M. avidus. Different intensity of 405 nm LED (20, 40, and 60 μmol·m^-2·s^-1) was illuminated on 2.2×10⁴ cells/well of M. avidus in a 24 well microplate for 24 h. Also, 2.4×10⁴ cells/well of M. avidus were exposed to varying combinations of 60 μmol·m^-2·s^-1 of 405 nm LED and serial 10-fold dilutions of formalin (from 10 to 100 ppm) for 15, 30, 45, and 60 min. Surviving M. avidus were counted using a hemocytometer. For in vivo test, flounder acclimatized at 11-12 practical salinity unit (psu) were challenged with 2×10⁶ cells/ml of M. avidus by immersion method for 1 h. Then, fish were moved and divided into four groups; "F" group, treated with formalin at 50 ppm; "L" group, treated with 60 μmol·m^-2·s^-1 of 405 nm LED; "C" group, treated with combination of the two methods; and the control group. After treatment for 30 min, fish were transferred to new tanks (salinity = 11-12 psu) and observed for 3 weeks. As a result, illumination of 405 nm LED at 60 μmol·m^-2·s^-1 killed 100% of M. avidus after 12 h, while 67% and 90% of the scuticociliate died at 20 and 40 μmol·m^-2·s^-1, respectively, after 24 h exposure. One hundred percent of M. avidus was killed at 90, 80, 80 and 70 ppm after exposure to formalin for 15, 30, 45 and 60 min, respectively. However, combined method (e.g., 60 μmol·m^-2·s^-1 of 405 nm-LED plus 50 ppm formalin) killed the parasite within 30 min. From in vivo test, similarly, survival rates of fish challenged with M. avidus were 100%, 43%, 29% and 0% in the C, F, L, and control groups, respectively. Results obtained in this study demonstrates that the combined treatment method has clear synergistic effect on scuticociliatosis in fish.

• The Journal of the Korea Contents Association
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• v.22 no.5
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• pp.404-415
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• 2022

The purpose of this study is to propose considerations to help actual application based on the characteristics of the online art-based peer supervision execution process. Colleagues in the clinical art therapy doctoral program, including the researcher, attempted to repeatedly identify problems and apply improvements in the implementation process as research participants, and qualitatively analyzed the various data collected in the process. Looking at the characteristics of the analysis results, extensibility of materials and space was confirmed in terms of 'art-based' and initiative, convenience, and speed in terms of 'online'. The considerations identified through this are as follows. First, 'pre-structuring' should be based on clear boundaries and setting, prior consultation of the group, and self-directed preparation and attitude. Second, for the 'structural aspect of art', space and media to help immersion through creation, and stable implementation structure should be established. Third, in the 'technical aspect', it is necessary to apply a method that can deliver a work of art and a method that can communicate the creator's clear intention. Lastly, for the 'ethical aspect', it is necessary to use online software in accordance with the minimum security standards and to make efforts to repeatedly maintain confidentiality. This study is meaningful in that it suggested a practical method for maintaining the professional competence of art therapists and expanding networks among art therapists in various situations including pandemics.