• Journal of the Korean institute of surface engineering
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• v.54 no.4
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• pp.171-177
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• 2021

This paper is concerned with the surface hardness measurement of NiP-coated AA7050 using different loads from 10 to 100 g. The surface hardness was observed to increase from 180 to 600 H_v with increasing NiP layer thickness, depending on the load applied for indentation. When NiP coating thickness is thinner than 2 ㎛, the surface hardness of NiP-coated AA7050 was mainly determined by AA7050 substrate, while it was significantly increased by NiP coating layer when NiP coating thickness is thicker than 2 ㎛. Hardness of AA7050 substrate itself was not dependent on the applied load but the hardness of NiP-coated AA7050 was largely influenced by the load applied for indentation. The largest difference of hardness between 10 g and 100g of applied loads, was obtained at the NiP thickness of about 8 ㎛ above which the measured hardness at 10 g reached a maximum value of about 600 H_v. It was also observed that indentation-induced plastic deformation next to the indented zone occurs when NiP layer is 5.64 times thicker than the depth of impression formed by indentation.

• Journal of the Korea Convergence Society
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• v.11 no.10
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• pp.163-169
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• 2020

The purpose of this study was to identify the degree of awareness and need for dental health insurance of parents with children under 12 years of age, and provide it as basic data for the development of the dental health insurance system in the future. It was conducted with 158 parents who are raising children under the age of 12 in Busan and Gyeongnam areas. In the case of mothers(p=.001), the higher the age (p=.005), the higher the experience of sealant. In the case of mothers, the knowledge of sealant (p=.012) was high. When the gender was female (p=.026), the parenting relationship was mother (p=.006), and regularly engaged in vocational activities (p=.003), the awareness of resin filling was high, and the experience was the child's age (p=. 004) was higher, the higher the knowledge was when the parenting relationship was mother (p=.024). The factors influencing the satisfaction of sealant were found to be the parents education level (p=.004), the awareness of the sealant (p=.003), and the experience (p=.011). From the above research results, more active publicity is needed to increase the awareness and experience of parents' health insurance.

• Korean Journal of Community Nutrition
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• v.20 no.2
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• pp.96-108
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• 2015

Objectives: This study was performed to investigate health-related factors, nutrition knowledge and food habits of college students in Wonju. Methods: A total of 442 (male: 221, female: 221) college students were recruited and a questionnaire-based survey was conducted. The general characteristics, health-related factors, nutrition knowledge, and food habits were investigated and data were analyzed using SPSS WIN (ver 21.0). Results: The body mass index ($22.9kg/m^2$ vs $20.9kg/m^2$, p < 0.001) was significantly higher in the males. The ratio of weight (p < 0.001) was significantly different between males and females. Health-related factor scores 'Exercise (p < 0.001)', 'Number of exercise (p < 0.001)', 'Times of exercise (p < 0.01)', 'Concerns about health (p < 0.05)', 'Health condition (p < 0.001)' were significantly higher in the males. 'Type of exercise (p < 0.001)' was significantly different between males and females. Score on 'Watching TV & computer games (p < 0.01)' was significantly higher in the females. Smoking (p < 0.001) was significantly higher in the males. Type of beverages consumed (p < 0.001) was significantly different between males and females. Nutrition knowledge score (11.8 vs 12.9, p < 0.05) was significantly higher in the females. Scores on 'Iron deficiency is leading to anemia (p < 0.01)' and 'carbonated beverages, such as coke, have no calorie (p< 0.05)' were significantly higher in the females. Food habits score (56.4 vs 53.7, p < 0.01) was significantly higher in the males. Scores on 'I have three meals a day (p < 0.01)', 'I have breakfast regularly (p < 0.001)', 'I have meals on time (p < 0.001)', 'I do exercise every day (p < 0.001)', 'I don't eat junk food often (p < 0.05)', 'I don't eat sweet food often (p < 0.05)', and 'I don't eat out often (p < 0.05)' were significantly higher in the males. Conclusions: Nutritional education for college students is needed in order to improve their health and nutritional education program should be tailored to meet various needs of these students.

• Journal of Soil and Groundwater Environment
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• v.14 no.1
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• pp.29-35
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• 2009

In this study, the effect of pH and temperature on the adsorption behavior of acid mine drainage (AMD) on coal mine drainage sludge (CMDS) has been investigated during the treatment of coal mine drainage (CMD) by electrical purification method. The pH$_{zero\;point\;charge}$ (pH$_{zpc}$) of CMDS was 5. The removal ratio of copper, zinc, cadmium, iron were increased according to the increase of pH value. The adsorption amount of copper showed 0.64 mg g$^{-1}$ sludge. It was independent of pH value. The adsorption amount of the other metals showed l.l times when pH was 3. The adsorption amount of chromium was a little bit increased at the pH value higher than 7 due to a small amount of the chromium was eluted as $Cr(OH)_6^{3-}$. The amount of metals' absorption were decreased according to temperature was increase at pH value was 3. The selectivity order was Cd>Fe > Zn > Cu. The amount of absorption showed q$_{max}$ Cu 2.747 mg g$^{-1}$ andZn 2.525 mg g$^{-1}$ when pH value higher than 5. It was independent of temperature.

• Journal of Sericultural and Entomological Science
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• v.17 no.2
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• pp.161-170
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• 1975

This study is to investigate the content of crude protein intruded in the sericin of cocoon shell and pupa by treatment of buffer solution (pH 1 to pH 13) 20 ml per 1 gram for 30 and 60 minutes at 30$^{\circ}C$, 60$^{\circ}C$ and 100${\pm}$2$^{\circ}C$, respectively. The results obtained are summarized as follows. 1. The quantity of total crude protein obtained from cocoon shell and pupa by treatment during 30 minutes at 30$^{\circ}C$ was dissolved as the largest quantity of 11.874 mg/g at pH 1 and l5.93mg/g at pH 13, but dissolved the smallest quantity 1.75g/g at pH 5 as known. and tile quantity of crude protein treated for 60 minutes is 13.437mg/g at pH 1 and 22.50mg/g at pH 13. Also, the smallest quantity is 2. 813mg/g at pH 5 as known. 2. By the treatment during 30 minutes at 60$^{\circ}C$, the dissolved largest quantity was 13.12mg/g at pH 1 and 21.875 mg/g at pH 13, but the smallest quantity is 2.375mg/g at pH 5 as known After treatment for 60 minutes at 60$^{\circ}C$, the dissolved largest quantity was 17.500 mg/g at pH 1 and 31.56mg/g at pH 13, bu the smallest quantity is 3.849 mg/g at pH 5. 3. The dissolved crude protein from the cocoon shell and pupa by treatment for 30 minutes at 100${\pm}$2$^{\circ}C$ was the largest quantity of 147.000mg/g at pH 1 and 398. 125mg/g at pH 13, but the smallest quantity is 75.00mg/g at pH 5 as known. After treatment for 60 minutes at 100${\pm}$2$^{\circ}C$, the largest quantity was 253.76 mg/g at pH 1 and 460.625mg/g at pH 13, but the smallest quantity is 139.375mg/g at pH 5 as known. 4. The dissolved crude protein from the cocoon shell and pupa was not different in quantity by treatment at 30$^{\circ}C$ or 60$^{\circ}C$. But dissolved crude protein was large quantity from cocoon shell more than pupa, as known. 5. The treatment of cocoon shell and pupa during 60 minutes at 100${\pm}$20$^{\circ}C$ was increased to the dissolved largest quantity of crude protein of 19.20％ at pH 1 and 22. 18％ at pH 13 from the cocoon shell and 6. 12％ at pH, an d 23.87％ at pH 13 from the pupa. But dissolved crude protein was increased to the larger quantity from pupa more than cocoon shell.

• Journal of Korean Society on Water Environment
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• v.31 no.6
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• pp.619-624
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• 2015

This study experimentally determined the effect of titanium tetrachloride (TiCl₄) concentration ([TiCl₄]) (0.25-0.55 mM) and initial pH (3-11) on phosphorus (P) removal in synthetic wastewater (2 mg P/L). The P removal efficiency increased when [TiCl₄] increased. The P removal efficiency showed a parabolic trend with an inflection point at pH 7. At the molar ratio of TiCl₄ and P>6.2, the P removal efficiency was over 90% and the residual P concentration was less than 0.2 mg/L. Within the design boundaries, the complete P removal could be achieved at 7.0≤initial pH≤8.5 and 0.43≤[TiCl₄]≤0.55 mM. The final pH was over 5.8 at initial pH≥7.7 and [TiCl₄]≥0.35 mM. The results showed that TiCl4 was effective in P removal in water so that it could be an alternative chemical for P removal.

• The Korean Journal of Emergency Medical Services
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• v.26 no.3
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• pp.21-35
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• 2022

Purpose: The purpose of this study was to investigate the effects of firefighters' job stress and emotional labor on their turnover intention, and analyze the main factors impacting turnover intention in this context. Methods: Based on a descriptive survey study design, we administered a structured questionnaire among 231 firefighters at one fire station in G metropolitan city from November 13 to 27, 2020. Results: Regarding job stress, participants showed differences based on marital status (p<.05), health status (p<.001), total service period (p<.05), and assignment (p<.05). For emotional labor, a significantly higher rate was observed for female than male firefighters (p<.05), with differences also observed in age (p<.001), health status (p<.001), total service period (p<.05), rank (p<.001), and assignment (p<.05). Further, for turnover intention, significant differences were noted with respect to age (p<.001), education (p<.01), health status (p<.001), total service period (p<.01), work unit (p<.05), rank (p<.001), and assignment (p<.05). A significant correlation was found between job stress and emotional labor and turnover intention. Regarding the factors affecting turnover intention, significant differences were noted based on education, rank, job stress, and emotional labor; the explanatory power was 53.9% (F=13.806, p<.001). Conclusion: Tailored support programs must be developed to ease firefighters' job stress and reduce their emotional labor to facilitate effective manpower management and reduce firefighters' turnover intention.

• Journal of Korean Public Health Nursing
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• v.9 no.1
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• pp.1-16
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• 1995

The purpose of this study was to find out and analyze the satisfaction degree related to job by general characteristics, satisfaction factors. This survey was based on the questionnaire method. The sample consisted of 51 noncommissioned officers, 72 administrative officers and 160 nurse officers from army hospitals. The data were collected from March 14 to April 18, 1994 and statistically analysed by percentage, mean and $x^2$ test. Factors of job satisfaction consist of 6 categories; job pristige, interaction, autonomy, task requirements, pay, and organizational requirements. The overall job satisfaction degree was $62.8\%$ in NCOs, $54.2\%$ in administrative officers and $33.3\%$ in nurse officers. The job satisfaction of NCCs increased in factors of job prestige (p<0.01), autonomy (p<0.05), task requirement (p<0.05), and was higher as age. There were statistically significant in the factors of pay in school background, Job prestige in rank (p<0.05). 'I'm OK and You're OK' type was $76.5\%$ which was the highest rate and A major personal traits also showed the highest job satisfaction $(63.7\%)$. There were significant difference between major personal traits and interaction (p<0.01), autonomy (p<0.05), organizational requirement (p<0.01), pay (p<0.05) and task requirement. The job satisfaction of administrative Officers was represented significant differences in factors of pay (p<0.05), task requirements (p<0.05) by school background. Long term Workers showed the highest job satisfaction and significant difference in factors of job prestige and organizational requirement (p<0.01). Job satisfaction in 'I'm OK but you're not OK' type was slightly high, and CP major personal traits also showed the highest job satisfaction. The job satisfaction of nurse officers was represented significant difference in factors of autonomy (p<0.01), job prestige (p<0.05), organizational requirement (p<0.05), and pay by age. In CP major personal traits. job satisfaction showed the highest rate (75.0)

• KSBB Journal
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• v.10 no.2
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• pp.191-195
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• 1995

Using Pseudomonas sp. CH-414, the optimum culture conditions were investigated for the cell growth and the phospholipid production in batch culture by varying pH and aeration rate. With starting the cultivation under the conditions of pH 7.0 and 1vvm, pH was controlled to 6 or 8 at 30 hours of culture time. In the case of changing into pH 6.0, the phospholipid production was increased by ca. 20% with comparison to the case of pH 7.0. However, the biomass and the phospholipld concentration were rapidly decreased after 30 hours of culture time when pH was controlled to 8.0. As the aeration rate was increased, the biomass was increased while the phospholipid concentration was considerably varied and unstable. Especially, the concentration of phospholipid was rapidly decreased with 3vvm of aeration rate. Finally, under the culture conditions of pH 7.0 and 3vvm until 30 hours for the cell growth, which were controlled to pH 6.0 and 1vvm for the stable production of phospholipid beyond that time, the dry cell weight was $18.5g/\ell$ and the phospholipid concentration was $\0.83g/ell$ (45mg/g cell).

• Toxicological Research
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• v.11 no.2
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• pp.205-213
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• 1995

This study was undertaken to investigate the effects of organic solvents on xenobiotic metabollzing enzyme system in vivo by meaas of experimental conditions i.e. (1) single group which was treated by benzene (B), toluene (T) and xylene (X), respectively, (2) combination group which was treated by mixture of benzene+toluene (BT), benzene+xylene (BX), and toluene+xylene (TX), respectively, (3) mixture group which was treated by benzene+ toluene+xylene mixture (M), and to interpreat the interaction between the organic solvents metabolizing enzymes. 1. The contents of cytochrome P-450 in liver microsomes were increased (p < 0.01) in organic solvents treated groups, and the contents of cytochrome P-450 were increased by following order of B < T < M < BT=BX < X < TX. 2. The activity of cytochrome P-450 dependent AHHase was significantly higher in organic solvents treated groups than in control group (p < 0.01), and the activity of AHHase was increased by following order of B < T < BT=BX=TX=xylene < M. 3. The activity of NADPH P-450 reductase was significantly higher in organic solvents treated groups than in control group (p < 0.01), and the order of M < combinated group < X < T