• Journal of the Korean Ceramic Society
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• v.35 no.12
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• pp.1301-1307
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• 1998

For dolomite clinkers used as stamp materials the corrosion behavior of those by molten steel was investigated in therange of temperatures between 1550$^{\circ}C$ and 1600$^{\circ}C$ IN hot face the dicalciumferrite of magnesioferrite and dicalciumferrite formed within dolomite clinkers was preferentially dissolved into molten steel and the protective layer of magnesioferrite was formed. For dolomite clinker without Fe2O3 magnesioferrite maintained the skeleton of MgO while the skeleton of CaO disappered bythe formation of dicalciumferrite and it existed as grain boundary phases of magnesioferrite. For dolomite clinker with Fe2O3 was diffused into hot face by the decomposition of dicalciumferrite. With increasing temperature of molten steel the formation depth of dicalciumferrite was increased and the magnesioferrite layer in hot face was decreased for dolomite clinker without Fe2O3 while the layer thickness and grain sizes of magnesioferrite in hot face was decreased for dolomite clinker without Fe2O3 while the layer thickness an grain sizes of magnesioferrite in hot face was increased due to the increment of the decomposition reaction of dicalciumferrite for dolomite clinker with Fe2O3.

• Journal of agricultural medicine and community health
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• v.34 no.2
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• pp.202-213
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• 2009

Objectives: The aim of this study was to compare health related behaviors among adolescents in the rural area with those in the urban area in Korea. Methods: The data source was the Korea Youth Risk Behavior Web-based Survey in 2005. With two stage cluster sampling, a total of 58,224 sample was selected from 799 middle and high schools nationwide. The area was classified into county area, small to medium city, and large city, and then the county area was considered as a rural area. Data was analyzed with STATA 9.0 using the method of complex survey data analysis considering sampling weight, strata, and primary sampling unit. Results: The prevalence of health related behaviors among adolescents in the rural area was higher than the city area as following health behaviors: smoking behaviors of smoking experience, smoking experience before entrance to middle school; drinking behaviors of frequent drinking, high risk behaviors with drinking; dietary behaviors of omitting of lunch or dinner, less intake of fruits or milk, more intake of cooky; oral hygiene of less tooth brushing, less preventive oral care, more oral symptoms and less dentist visit; safety behaviors of less wearing of safety belt or protective device; general hygiene of less hand washing before meal or after visiting rest room. Conclusions: The health behaviors among adolescents in the rural area were generally poorer than the city area. The results showed national health program for adolescents should be conducted primarily for those in rural areas. Further study is needed to explore the factors related with the discrepancy of health behaviors between the rural and urban area.

• Journal of the Korean Geotechnical Society
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• v.38 no.11
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• pp.107-118
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• 2022

The social need for stable hydrogen storage technologies that respond to the increasing demand for hydrogen energy is increasing. Among them, underground hydrogen storage is recognized as the most economical and reasonable storage method because of its vast hydrogen storage capacity. In Korea, low-depth hydrogen storage using artificial protective structures is being considered. Further, establishing corresponding safety standards and ground stability evaluation is becoming essential. This study evaluated the hydro-mechanical behavior of the ground during a hydrogen gas leak from a low-depth underground hydrogen storage facility through the HM coupled analysis model. The predictive reliability of the simulation model was verified through benchmark experiments. A parameter study was performed using a metamodel to analyze the sensitivity of factors affecting the surface uplift caused by the upward infiltration of high-pressure hydrogen gas. Accordingly, it was confirmed that the elastic modulus of the ground was the largest. The simulation results are considered to be valuable primary data for evaluating the complex analysis of hydrogen gas explosions as well as hydrogen gas leaks in the future.

• Economic and Environmental Geology
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• v.56 no.3
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• pp.229-238
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• 2023

Bentonite is a type of rock that has been used as a traditional mineral medicine. It has a variety of pharmacological activities, and is used in traditional Korean medicine to treat jaundice, diarrhea, and hemostasis. In modern medicine, it is used as a raw material and additive for medicines such as antacids, gastrointestinal protective agents, and laxatives. Bentonite produced in Korea was produced through diagenesis or hydrothermal alteration of tertiary volcanic debris distributed in the Pohang and Gyeongju areas. It is mainly used for industrial purposes such as papermaking, paint, civil engineering, casting, and animal feed. Recently, technology is being developed to use it in cosmetics and pharmaceuticals. In this study, the geochemical characteristics of bentonite were identified by analyzing the main components and trace elements of 40 and 21 types of bentonite produced in the Gampo Gyeongju and Yeonil Pohang area. Also it were classifed by formation envrionment of bentonite deposits in the Gampo and Yeonil. As a result of the study, bentonite from the reserch area may be cased by argillic alteraton that alkali elements are removed form basaltic rocks by hydrothermal fluids and AI-CCPI alteration indices wrere also indentified argillic alteraton. It was found that there is a correlation between the behavior characteristics of heavy metal elements (P b, Cr, As) and the hydrothermal alteration of bentonite in the reserch area.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.3
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• pp.319-332
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• 2009

The present study was performed to analyze the life style and eating behavior of stroke patients and to find the risk factors related to stroke incidence in Daegu and Gyeongbuk Province, Korea. The case subjects (n=100) were selected from newly diagnosed stroke patients at Kyungpook National University Hospital. The control subjects (n=150) were selected from community inhabitants who did not have stroke history and were sex and age-matched with the case subjects. The survey was conducted by individual interviews using questionnaires on the general characteristics, life-style, eating behavior, food intake frequency and food preference. The high body mass index, preexisting diseases such as diabetes and hypertension, stroke family history, smoking, overeating habit and high preference for sweet, greasy and meat foods appeared to be the risk factors for stroke incidence. On the other hand, the results suggest that life style of regular exercise and nonsmoking, food habits of green tea drinking and enough chewing, preference for Korean meal type, high intake frequency for legumes, vegetables, mushrooms, seaweeds, fishes and shell fishes, soy milk and green tea might be the protective factors for the stroke. Therefore, maintenance of healthy weight, the prevention and management of the deteriorative chronic diseases, change of life style and improvement of eating behaviors are considered to be important for stroke prevention.

• Journal of Venture Innovation
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• v.5 no.2
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• pp.49-66
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• 2022

This study intends to examine how the perception of covid-19 risk affects consumers' consumption behavior based on previous studies in a situation where the spread of covid-19 is prolonged. This study demonstrates how consumers' perception of covid-19 risk affects online and offline consumption behavior through the perceived severity, perceived vulnerability, coping effectiveness, and self-efficacy of the revised protective motivation theory (Rogers, 1983). We want to test it through analysis. In order to achieve the purpose of this study, consumers living in Seoul and Gyeonggi Province who have purchased within the past 3 months were selected as a sample. In addition, variable data such as risk perception of covid-19, perceived severity, perceived vulnerability, coping effectiveness, self-efficacy, online purchase attitude and purchase intention, offline purchase attitude and purchase intention were collected through the questionnaire.A total of 363 copies of valid responses were tested to test the hypothesis of the relationship between variables through the covariance structure model. The analysis results of this study were first, that covid-19 risk perception had a significant positive (+) effect on perceived severity, perceived vulnerability, and coping effectiveness. Second, perceived severity and perceived vulnerability were found to have a significant positive (+) effect on offline purchasing attitude. Third, perceived severity, perceived vulnerability, coping plan effectiveness, and self-efficacy were all found to have significant positive (+) effects on online purchase attitude. Finally, it was found that offline purchase attitude and online purchase attitude had a significant positive (+) effect on offline purchase intention and online purchase intention, respectively. Also, it was found that online purchase attitude had a negative (-) effect on offline purchase intention. The results of this analysis will provide meaningful implications for the establishment of strategies for distribution channels according to the social risk of infectious diseases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.401-408
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• 2020

This study was undertaken among students majoring in Emergency Medical Technology, to comprehend the knowledge, attitudes and preventive behaviors associated with MERS. This study further provides basic data for education related to MERS prevention. A total of 167 students were enrolled in the study. Evaluation of MERS education revealed a higher number of inexperienced subjects: 74 experienced(44.3%) vs. 93 inexperienced(55.7%). Assessing the attitude items for MERS revealed that "have to wear personal protective equipment when dealing with MERS patients" ranked highest (average, 4.54 ± 0.87), whereas "washed my hands more often than usual" ranked highest (average, 3.82 ± 1.06) in the prevention items for MERS. Analyzing the correlation between attitude towards MERS and preventive behavior revealed that "canceled or delayed meeting with friends, eating out, watching sports, shopping, etc." showed that, although negatively correlated, a greater attitude showed a higher level of prevention (r=-0.63, p<0.004). Taken together, results of this study indicate the necessity to develop an education program that improves the level of education and knowledge about MERS, and to impart this education systematically and repeatedly.

• Journal of the Korean Electrochemical Society
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• v.2 no.3
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• pp.150-155
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• 1999

The Electrochemical stabilities of the Brewer-Engel type intermetallic compounds of Co-Mo $(35 wt\%)$ and Ni-Mo$(35 wt\%)$ manufactured by the arc-melting method for the hydrogen electrode of $H_2-O_2$ alkaline fuel cell were investigated. Effects of temperature and concentration on the electrochemical behavior of the electrodes in the $80^{\circ}C$ 6 N KOH solution deaerated with $N_2$ gas were studied by electrochemical methods. The effect of overpotential on the electrochemical stabilities of Co-Mo and Ni-Mo intermetallic compounds was also discussed under the normal operation condition of AFC. It was shown that Co-Mo electrode had lower electrochemical stability as compared to Ni-Mo. In the case of Co-Mo electrode, a simultaneous dissolution of cobalt and molybdenum has occurred at low anodic overpotential form equilibrium hydrogen electrode potential, but the dissolution of cobalt was serious, and Co(OH)l layer on the electrode surface formed at the high anodic overpotential. In contrast the Ni-Mo electrode had high electrochemical stability because formation of the dense and thin protective $Ni(OH)_2$ layer prevented the dissolution of molybdenum.

• Journal of the Korean Electrochemical Society
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• v.19 no.1
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• pp.1-8
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• 2016

Capacity of layered lithium nickel-cobalt-manganese oxide ($LiNi_{1-x-y}Co_xMn_yO_2$) cathode material can increase by raising the charge cut-off voltage above 4.3 V vs. $Li/Li^+$, but it is limited due to anodic instability of conventional electrolyte. We have been screening and evaluating various sulfone-based compounds of dimethyl sulfone (DMS), diethyl sulfone (DES), ethyl methyl sulfone (EMS) as electrolyte additives for high-voltage applications. Here we report improved cycling performance of $LiNi_{0.5}Co_{0.2}Mn_{0.3}O_2$ cathode by the use of dimethyl sulfone (DMS) additive under an aggressive charge condition of 4.6 V, compared to that in conventional electrolyte, and cathode-electrolyte interfacial reaction behavior. The cathode with DMS delivered discharge capacities of $198-173mAhg^{-1}$ over 50 cycles and capacity retention of 84%. Surface analysis results indicate that DMS induces to form a surface protective film at the cathode and inhibit metal-dissolution, which is correlated to improved high-voltage cycling performance.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.5
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• pp.189-204
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• 2016

The study is aimed at figuring out the effect of the consumers benefit, attitudes and interest when customers purchase functional food on purchasing intention and product a foundation of competitive power such as a customized product development for a marketing strategy by examining consumers' behavioral patterns. The range of functional food which is a subject of this study is included in the nutraceutical foods, protective foods in addition to biocontrol food. It surveyed about ages of 20 to 60 domestic residents who have taken functional food in order to conduct the study. Data used in this study was collected 353 answers in September 2016, and hierarchical analysis which is a demographic characteristic as control variables was conducted to verify the hypothesis using statistical program SPSS 21.0 The result of this study demonstrates that firstly, psychological pursued benefit secondly, health concern thirdly, health management attitude affects to functional purchasing intention. It is expecting that the result of this study will be used on the basic standards that are grasping and generalizing the needs of customers. In addition, it is also expecting to contribute to improvement of internal and external functional food industry as a functional food material development because it provides empirical customer behavior analysis result.