• Applied Chemistry for Engineering
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• v.31 no.2
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• pp.164-171
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• 2020

Adsorption characteristics of reactive red 120 (RR 120) dye by a coal-based granular activated carbon (CGAC) from an aqueous solution were investigated using the amount of activated carbon, pH, initial concentration, contact time and temperature as adsorption variables. Isotherm equilibrium relationship showed that Langmuir's equation fits better than that of Freundlich's equation. The adsorption mechanism was considered to be superior to the adsorption of monolayer with uniform energy distribution. From the evaluated Langmuir separation coefficients (R_L = 0.181~0.644), it was found that this adsorption process belongs to an effective treatment area (R_L = 0~1). The adsorption energy determined by Temkin's equation and Dubinin-Radushkevich's equation was E = 15.31~7.12 J/mol and B = 0.223~0.365 kJ/mol, respectively. The adsorption process showed the physical adsorption (E < 20 J/mol and B < 8 kJ/mol). The adsorption kinetics followed the pseudo first order model. The adsorption reaction of RR 120 dye on CGAC was found to increase spontaneously with increasing the temperature because the free energy change decreased with increasing the temperature. The enthalpy change (12.747 kJ/mol) indicated an endothermic reaction. The isosteric heat of adsorption (△H_x = 9.78~24.21 kJ/mol) for the adsorption reaction of RR 120 by CGAC was revealed to be the physical adsorption (△H_x < 80 kJ/mol).

• Korean Journal of Legislative Studies
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• v.23 no.1
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• pp.113-149
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• 2017

This study aims to identify the micro-level, social psychological foundation of regionalism and analyze its change and continuity by comparing 1988, 2003, and 2016 survey results. Drawing on the theory of prejudice and social identity, it clarifies the concept of regionalism and examines its affective, behavioral, cognitive implications. In the empirical analysis, where it takes advantage of relevant questions of the same or similar wording in three nationally representative surveys, the study identifies the changes in regionalism at the individual level focusing on anti-Honam prejudice and discrimination and attribution of regional conflict. First, anti-Honam prejudice has been in decline nationally as well as regardless of where one has grown up, except for Daegu/Kyungpook area. Second, anti-Honam prejudice has been weakened among younger generations while regional party identification now affects the sentiment in the direction of regional cleavage overlapped with ideological leanings. Third, while most respondents do not experience explicit discrimination, Honam natives are still more likely to experience discrimination, especially identity and self-esteem related, due to his or her home town. Fourth, Honam natives have been more likely to attribute regional conflict to an external, structural factor like government economic policy and less likely to a subjective one like regional sentiment, which seems to be consistent with attributional attitudes of the victims of prejudice. The study ends with the discussion of how to reduce further anti-Honam prejudice, which includes contact hypothesis, recategorization, cross-categorization, and de-categorization.

• Journal of the Korean Geophysical Society
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• v.4 no.1
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• pp.57-69
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• 2001

We have carried out a nondestructive close examination for the purpose of the structural safety diagnosis of the Three-Story Pagoda(Seokga Pagoda) in Bulkuk temple in the city of Kyungju, Kyungbuk, Korea. Ultrasonic wave velocities were measured at 456 points of the pagoda comprising 44 blocks to estimate the mechanical properties of rock blocks constituting the pagoda. The measured velocities have the range of 1217 to 4403 m/sec with the average of 3227 m/sec. The empirical relationship between the ultrasonic velocity and the uniaxial compressive strength yielded the estimation of strength of each block, ranging from 134 to 844 kg/cm^2 and averaging 463 kg/cm^2. With an assumption that the strength of each block is described as a random variables having a normal distribution, we calculated the probability of failure of rock blocks of the pagoda. Our investigation revealed that the probability of the structural failure due to the weight of higher blocks is very low. However, the probability of partial failure around contact area is substantial, which is consistent with the appearance that edges and the corners of some blocks were broken off. The platform under the body of the pagoda appeared to be structurally weak as the probability of tensile failure of the lower platform is up to 18%, and diagonal fractures are shown where the probability of failure is high.

• The Korean Journal of Franchise Management
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• v.12 no.3
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• pp.7-19
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• 2021

Purpose: The hotel industry needs a leader who can actively demonstrate leadership to respond to and accept changes in the organization in a highly competitive and fast-changing environment. Therefore, the role of leaders who instill clear vision and goals of the organization in their members, listen to their opinions, and empathize is paramount. Leaders should encourage successful organizational activities based on active participation by employees and create the best environment for working with a sense of mission and responsibility. This study aims to identify the relationship between empathy leadership and job engagement as a result variable of team cohesion in the hotel culinary department and conduct empirical studies on the role of empathy leadership and job engagement. Research design, data, and methodology: The data were collected from employees who work in culinary department at a five-star franchise hotel located in the Seoul metropolitan area. Because it is difficult to conduct a survey through face-to-face contact with employees due to the COVID-19 pandemic, the online survey was conducted from February 1 to February 28, 2020. A total of 330 questionnaires through online were distributed and 268 employees completed the survey, yielding a response rate of 81%. Of the 268 returned responses, 27 responses were not usable due to missing information. Thus, a total of 241 responses were used for analysis. Results: The study results are as follows. First, it has been shown that the empathy leadership of culinary department in hotel companies has a significant positive impact on the job engagement. Second, it has been shown that job engagement has a significant positive effect on members' team cohesiveness. Third, empathy leadership of hotel companies' culinary department has a significant positive impact on members' team cohesiveness. Fourth, job engagement has a significant positive (+) mediating effect in the relationship between empathy leadership and team cohesiveness in culinary department. Conclusion: This study supports the theory that an emotional and empathic leader's behavior or ability can change the effectiveness or atmosphere of a rapidly changing hotel culinary team organization by presenting a research model on the effect of empathic leadership on job engagement and team cohesiveness. And hotel chefs should be more aware of the importance of empathic leadership and make them a human resource of the organization through formal and informal communication with culinary employees.

• The Korean Journal of Franchise Management
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• v.12 no.3
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• pp.35-46
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• 2021

Purpose: The hotel industry needs a leader who can actively demonstrate leadership to respond to and accept changes in the organization in a highly competitive and fast-changing environment. Therefore, the role of leaders who instill clear vision and goals of the organization in their members, listen to their opinions, and empathize is paramount. Leaders should encourage successful organizational activities based on active participation by employees and create the best environment for working with a sense of mission and responsibility. This study aims to identify the relationship between empathy leadership and job engagement as a result variable of team cohesion in the hotel culinary department and conduct empirical studies on the role of empathy leadership and job engagement. Research design, data, and methodology: The data were collected from employees who work in culinary department at a five-star franchise hotel located in the Seoul metropolitan area. Because it is difficult to conduct a survey through face-to-face contact with employees due to the COVID-19 pandemic, the online survey was conducted from February 1 to February 28, 2020. A total of 330 questionnaires through online were distributed and 268 employees completed the survey, yielding a response rate of 81%. Of the 268 returned responses, 27 responses were not usable due to missing information. Thus, a total of 241 responses were used for analysis. Results: The study results are as follows. First, it has been shown that the empathy leadership of culinary department in hotel companies has a significant positive impact on the job engagement. Second, it has been shown that job engagement has a significant positive effect on members' team cohesiveness. Third, empathy leadership of hotel companies' culinary department has a significant positive impact on members' team cohesiveness. Fourth, job engagement has a significant positive (+) mediating effect in the relationship between empathy leadership and team cohesiveness in culinary department. Conclusion: This study supports the theory that an emotional and empathic leader's behavior or ability can change the effectiveness or atmosphere of a rapidly changing hotel culinary team organization by presenting a research model on the effect of empathic leadership on job engagement and team cohesiveness. And hotel chefs should be more aware of the importance of empathic leadership and make them a human resource of the organization through formal and informal communication with culinary employees.

• Journal of Periodontal and Implant Science
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• v.51 no.5
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• pp.352-363
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• 2021

Purpose: Some systemic conditions, especially diabetes mellitus (DM), adversely affect dental implant success. This study aimed to investigate the effects of ibuprofen-loaded TiO₂ nanotube (ILTN) dental implants in alloxan-induced diabetic rabbits. Methods: Twenty-six New Zealand white rabbits were treated with alloxan monohydrate to induce DM. At 2 weeks following DM induction, 3 types of implants (sandblasted, large-grit, and acid-etched [SLA], ILTN, and machined) were placed into the proximal tibia in the 10 rabbits that survived following DM induction. Each type of implant was fitted randomly in 1 of the holes (round-robin method). The animals were administered alizarin (at 3 weeks) and calcein (at 6 weeks) as fluorescent bone markers, and were sacrificed at 8 weeks for radiographic and histomorphometric analyses. Results: TiO₂ nanotube arrays of ~70 nm in diameter and ~17 ㎛ in thickness were obtained, and ibuprofen was loaded into the TiO₂ nanotube arrays. A total of 26 rabbits were treated with alloxan monohydrate and only 10 rabbits survived. The 10 surviving rabbits showed a blood glucose level of 300 mg/dL or higher, and the implants were placed in these diabetic rabbits. The implant stability quotient (ISQ) and bone-to-implant contact (BIC) values were significantly higher in the ILTN group (ISQ: 61.8, BIC: 41.3%) and SLA group (ISQ: 62.6, BIC: 46.3%) than in the machined group (ISQ: 53.4, BIC: 20.2%), but the difference in the BIC percentage between the SLA and ILTN groups was not statistically significant (P=0.628). However, the bone area percentage was significantly higher in the ILTN group (78.0%) than in the SLA group (52.1%; P=0.000). Conclusions: The: ILTN dental implants showed better stability (ISQ) and BIC than the machined implants; however, these values were similar to the commercially used SLA implants in the 2-week diabetic rabbit model.

• International Area Studies Review
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• v.22 no.2
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• pp.139-162
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• 2018

Although the hotel industry in China has shown great growth both quantitatively and qualitatively, there is a lack of management of employees who represent hotels in direct contact with customers. Therefore, this study examined the social support of Chinese 4, 5 star hotel employees in Shanghai as supervisory support, coworker support, and family support, and examined whether the social support of employees improves resilience and affects their psychological well-being. In order to analyze this, we surveyed 322 employees of Shanghai 4, 5 star hotels in China. Empirical analysis showed that supervisory support and family support had a positive effect on their resilience, while coworker support did not. In addition, the resilience of hotel employees has a positive effect on their psychological well-being. This study aims to provide a better understanding of social support and resilience, and to provide effective management of human resources management.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.2
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• pp.13-18
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• 2019

Sewage sludge treatment is increasing every year due to improvement of living and urbanization. However, interest in anaerobic digestion which is one of the recycling technology. There is anaerobic digestion of increasing due to limitations of ocean dumping and final disposal. But, the limit of anaerobic digestion efficiency due to the advanced treatment of sewage has been limited, and studies for solubilization technology have been actively conducted. Therefore, in this study, we aimed to investigate the variation of generation of scum and the solubilization efficiency in the application of pre-treatment of ozone reaction and the change of properties of digested sludge with wet milling. There are results of VS/TS increased by 4.4% and $SCOD_{cr}/TCOD_{cr}$ increased by 9.4% by wet milling alone. In addition, the increase of the specific surface area due to which the reduction of the particle size of the solid content of the sludge in the ozone reaction caused by wet milling decreased the generation rate of scum at 14.3% and increased VS/TS at 2.1%, compared with the ozone reaction alone. From these results, it is expected that the application of wet milling can be increased the contact efficiency with solids in the sludge during ozone reaction with suppress scum and increase the efficiency of the subsequent process in anaerobic digestion.

• Korean Journal of Ornithology
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• v.25 no.2
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• pp.94-100
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• 2018

Bird electrocution on contact with electricity lines is well reported and is quite common in Mongolian open areas. We visited 15-kV electricity distribution pole lines in a Southern Mongolian semi-desert region three times in 2017, in April, July, and September, to assess their risks to birds. The carcasses of 45 electrocuted birds representing 12 species were identified from 250 poles (overall mortality rate of 1.12% every 10 km). The majority of these electrocuted birds were endangered Saker Falcon (n=11) and common Black Kite (n=11). The lacks of roosting or perching sites in our study sites (indeed other open areas in Mongolia) may resulted for such high rate bird electrocution. A 751-base pair (bp) cytochrome c oxidase I (COI) gene was amplified for DNA sequence-based identification of carcasses that were difficult to identify directly. Our findings revealed the high electrocution risk for birds in Mongolian open areas, especially for the birds of prey, with relatively low-efficiency electrocution mitigation approaches. The findings also indicate that there is a need for better understanding of the risk of bird electrocution, particularly in the open areas. This will contribute to the conservation of endangered species.

• The Journal of the Korea Contents Association
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• v.18 no.11
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• pp.540-549
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• 2018

This study was conducted on 238 dental hygienists working in Daegu and Gyeongbuk area. In order to understand the status of harmful transmission of dental materials by type of work, we compared the differences in exposure time and work environment characteristics of hospital types and investigated the difference in the degree of recognition of material safety data. The results of the study were as follows: In case of hospitals, the exposure time of dust generated from chemicals was the longest. Resin filling, contact with disinfectant. 37 workers (29.4%) and 14 workers (12.5%) answered that they perceive the question about whether they are aware of the material safety data sheet (MSDS) for dental materials. There were 18 hospital workers and 6 clinic workers who had experience reading MSDS before using dental materials. The respondents who answered that they provided the material safety data of the dental materials used had a 2.39 times MSDS in hospital workers. Therefore, by recognizing the health hazards of chemical substances in accordance with the characteristics of each type of hospital and continuing to conduct health and safety education, the work environment should be improved by establishing proper recognition of MSDS information. It suggests the necessity of a system that can strengthen the management of chemical information provision and guarantee the strategic approach and workers' right to know.