• Korean Journal of Microbiology
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• v.45 no.4
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• pp.411-415
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• 2009

Some microorganisms are capable of leaching Mn(II) from nonsulfidic manganese ores indirectly via nonenzymatic processes. Such reductive dissolution requires organic substrates, such as glucose, sucrose, or galactose, as a source of carbon and energy for microbial growth. This study investigated characteristics of Mn(II) leaching from manganese nodules by using heterotrophic Bacillus sp. strain MR2 provided with corn starch as a less-expensive substrate. Leaching of Mn(II) at 25.6 g Mn(II) $kg^{-1}$ nodule $day^{-1}$ was accompanied with cell growth, but part of the produced Mn(II) re-adsorbed onto residual $MnO_2$ particles after 24 h. Direct contact of cells to manganese nodule was not necessary as a separation between them with a dialysis tube produced similar amount [24.6 g Mn(II) $kg^{-1}$ nodule $day^{-1}$]. These results indicated an involvement of extracellular diffusible compound(s) during Mn(II) leaching by strain MR2. In order to optimize a leaching process we tested factors that influence the reaction, and the most efficient conditions were $25\sim35^{\circ}C$, pH 5~7, inoculum density of 1.5~2.5% (v/v), pulp density of 2~3 g/L, and particle size <75 ${\mu}m$. Although Mn(II) leaching was enhanced as particle size decrease, we suggest <212 ${\mu}m$ as a proper size range since more grinding means more energy consumption The results would help for the improvement of bioleaching of manganese nodule as a less expensive, energy-efficient, and environment-friendly technology as compared to the existing physicochemical metal recovery technologies.

• Journal of Korean Home Economics Education Association
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• v.25 no.2
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• pp.103-128
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• 2013

The purpose of this study was to develop a school violence prevention program featuring the Practical Action Teaching Model(hereafter, PATM) for middle school students to prevent school violence by Home Economics Education. To accomplish this purpose, the processes of analysis, design, development, and evaluation based on ADDIE were conducted. The validity of the program was evaluated twice by Home Economics education experts(36 experts for the first group and 10 experts for the second group) and the contents of the program were modified according to the comments from the evaluators. The school violence prevention program in Home Economics classes consisted of 5 topics such as changing perception on school violence, enhancing self-esteem, relating with others, practicing consideration and sharing, and strengthening the will of preventing school violence. Twenty-four units were developed with 7 practical problems(What should I do to make friends to help with each other?, What should I do to establish positive self-concept?, What should I do to communicate to build good relationship?, What should I do to solve the conflicts peacefully?, What should I do to practice consideration and sharing in food consumption?, and What should I do to practice consideration and sharing in clothing?) in 5 topic areas. Teaching-learning plans included four steps such as problem perception, practical reasoning, action, and evaluation that comprise PATM to solve the practical problems. Every step of the teaching-learning plan consisted of questions for practical reasoning and activity assignments. Materials for students and teachers were developed. Materials for students comprised 80 pieces in total including student activity, reading, movie, and clips to make students enhance understanding and interest. Materials for teachers comprised 35 pieces in total such as rationales, newspaper articles, and movies that make teachers that lesson teaching loads and were helpful for teachers. The PATM was incorporated into developing the program and a Likert-scale was used to assess usefulness, applicability, appropriateness, fidelity, substantiality, and validity of this program. This program gained more than 4.00 on a 1-5 Likert scale. This result indicated that program is expected to be effective and useful to school violence prevention.

• Korean Chemical Engineering Research
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• v.48 no.2
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• pp.275-282
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• 2010

A characteristic study of aqueous chlorine dioxide generation from sodium chlorite($NaClO_2$) by an undivided electrochemical cell with different anode materials were performed. $IrO_2$-coated Ti, $RuO_2$-coated Ti and DSA were used as anode materials and Pt-coated Ti electrode was used as cathode. Various electrochemical cell operating parameters such as cell residence time($t_R$), initial feed solution pH, sodium chlorite and sodium chloride(NaCl) concentration and applied current for the generation of chlorine dioxide in an un-divided cell were investigated and optimized. Estimated optimal cell residence times in $IrO_2$-coated Ti, $RuO_2$-coated Ti and DSA anode material systems were around 2.27, 1.52 and 1.52 sec, respectively. Observed optimum initial feed solution pH was around 2.3 in all anode material systems. Optimum sodium chlorite concentrations in $IrO_2$-coated Ti, $RuO_2$-coated Ti and DSA anode systems were around 0.43, 0.43 and 0.32 g/L, respectively. Optimum electrolyte concentration and applied current were around 5.85 g/L and 0.6 A in all anode systems. Current efficiencies of $IrO_2$-coated Ti, $RuO_2$-coated Ti and DSA anode systems under optimum conditions were 79.80, 114.70 and 70.99%, respectively. Obtained energy consumptions for the optimum generation of chlorine dioxide were 1.38, 1.03 and $1.61W{\cdot}hr/g-ClO_2$, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.5
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• pp.618-625
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• 2009

The purposes of this study were to evaluate food safety knowledge and to assess home food safety performance of home-delivered meal service recipients. Two facilities providing home-delivered meal services for older adults were located in Seoul. A total of 120 service recipients were surveyed using an individual interview technique and 97 responses were used for data analysis. A statistical data analysis was completed using SPSS program (ver.14) for descriptive analysis, t-test, ANOVA, and correlation analysis. The majority of the participants were 70 years old or older and females. They perceived their health status as poor or very poor and took more than one kind of medicines. An average score of the food safety knowledge test was 11.48 based on 18 points (63.8%). The results revealed that the older adults knew the importance of hand washing but were not aware of when and how to wash hands. There was room to improve knowledge on cleaning and sanitizing fresh fruits and using wiping cloth. The knowledge score for each category was not significantly different by gender and age. The home food safety practices of the older adults was rated as 2.8 out of 4 points; the highest score was associated for proper food handling category and the lowest score was for cleaning and sanitizing. The worst performance was related to managing hand cuts and wounds (1.96). The total knowledge score and an average performance score were significantly correlated (p<0.01). Food safety education programs targeting the older adults who receive home-delivered meal services would improve the recipients' food safety knowledge and practices related to consumption of the meals at home. The programs should focus on not only improving food safety knowledge but also changing food safety practices.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1397-1407
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• 2017

The aim of a school attendance policy (SAP) is to ensure breakfast time for school-aged adolescents. Therefore, this study investigated the effects of SAP on dietary behavior, particularly breakfast consumption, among adolescent middle school students (n=426) in the Ansan area of Gyeonggi-do. After implementation of the SAP, the response rates for eating breakfast every-day among boys (P>0.05) and girls (P<0.05) slightly increased by 44.6% and 35.8%, respectively, compared to before the SAP. Further, the degree of satisfaction with breakfast increased among both boys ('satisfied' and 'strongly satisfied'; 32.4% and 21.6%, respectively) (P<0.01) and girls ('satisfied' and 'strongly satisfied'; 32.8% and 14.2%, respectively) (P<0.001) compared to before the SAP. Moreover, boys (56.8%) and girls (53.9%) were aware that the SAP increased breakfast-eating frequency. Increases in deep sleep as a result of the SAP were high in both boys (39.2%) and girls (47.1%), and sleeping hours among boys (P<0.05) and girls (P<0.01) increased compared to before the SAP. The respondents were aware of the positive effects on physical function such as reduction of physical fatigue (boys 40.1%, girls 38.2%) and improvement of physical health (boys 36.5%, girls 32.8%). Thus, systematic and sustained political support at the national level is required to encourage healthy breakfast eating and physical activity in middle school students.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.322-326
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• 2012

Recently, researches related to plant factory system has been activated and production of Ssam-vegetables using artificial lighting has been increasing. In South Korea, Ssam-vegetables are very popular and the consumption is increasing every year. Because leaf vegetables cultivated under hydroponic systems are more preferable rather than those cultivated by soil culture in Korea, the plant factory system would be more effective in production of Ssam-vegetables. Therefore, this study was carried out in order to analyze the yield and vitamin C contents in red mustard (Brassica juncea L.) and pak-choi (Brassica campestris var. chinensis), which are used a lot for the Ssam-vegetables in South Korea, as influenced by different concentrations of the nutrient solution in a plant factory system. As a results, there was no significant differences in the plant height among the treatment of EC in the nutrient solution, but for red mustard plants, the number of leaves tended to decrease in the treatment with higher EC. Leaf area of pak-choi plants was significantly increased in the higher EC, while the fresh weight had a tendency to increase along with increasing EC in the nutrient solution for both crops. The photosynthetic rates did not show a distinct tendency by EC levels for red mustard plants, but for pak-choi plants, it tended to be higher at the high EC. The contents of ascorbic acid in leaves were higher with decreasing EC concentration in the nutrient solution for red mustard plants, while the content was the highest at EC $2.0dS{\cdot}m^{-1}$ for pak-choi plants. In summary, considering the marketable yields and vitamin C at different nutrient concentrations in a plant factory, the optimal concentration for red mustard and pak-choi plants was thought to be EC $2.0{\sim}2.5dS{\cdot}m^{-1}$.

• Journal of Bio-Environment Control
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• v.18 no.1
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• pp.29-39
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• 2009

The influence of windbreak to minimize the ventilation velocity near the plant canopy of a greenhouse strawberry was thoroughly investigated using computational fluid dynamics (CFD) technology. Windbreaks were constructed surrounding the plant canopy to control ventilation and maintain the concentration of the supplied $CO_2$ from the soil surface close to the strawberry plants. The influence of no windbreak, 0.15 m and 0.30 m height windbreaks with varied air velocity of 0.5, 1.0 and 1.5 m/s were simulated in the study. The concentrations of supplied $CO_2$ within the plant canopy of were measured. To simplify the model, plants were not included in the final model. Considering 1.0m/s wind velocity which is the normal wind velocity of greenhouses, the concentrations of $CO_2$ were approximately 420, 580 and 653 ppm ($1{\times}10^{-9}kg/m^3$) for no windbreak, 0.15 and 0.30 m windbreak height, respectively. Considering that the maximum concentration of $CO_2$ for the strawberry plants was around 600-800 ppm, the 0.30 m windbreak height is highly recommended. This study revealed that the windbreak was very effective in preserving $CO_2$ gas within the plant canopy. More so, the study also proved that the CFD technique can be used to determine the concentration of $CO_2$ within the plant canopy for the plants consumption at any designed condition. For an in-depth application of this study, the plants as well as the different conditions for $CO_2$ utilization, etc. should be considered.

• Korean Journal of Food Science and Technology
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• v.41 no.4
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• pp.428-434
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• 2009

This study was conducted to evaluate the anti-hypertensive effect of Lactobacillus sp. isolated from Kimchi by examining its effects on renal angiotensin-converting enzyme (ACE) inhibitory activity, lipid components and blood pressure using the spontaneously hypertensive rat (SHR) system. Most Lactobacillus sp. extracts (lysozyme, sonication and ethyl acetate extracts) showed higher capacities for the inhibition of ACE activity than those of cultured media. Particularly, LG 7, 8 and 42 of Lactobacillus sp. showed the strongest inhibitory activity among the Lactobacillus sp. extracts. The concentrations of total cholesterol and triglycerides in the serum were lower in the Lactobacillus sp. administration groups than in the control group, but these differences were not significant. The HDL-cholesterol concentrations of the LG 42 administration groups (IX, X) were significantly higher than that of the control group. At 4 weeks, the systolic blood pressure (SBP) in the LG 42 Lactobacillus sp. ($1{\times}10^9$ cfu/mL) group (XI) was about 27% lower than that of the control group (V). No adverse effects were observed on the liver and there was no difference in the aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values among groups. The results of this study suggest that long term consumption of LG 42 Lactobacillus sp. may be beneficial to the prevention of high blood pressure.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.6
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• pp.942-947
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• 2003

The effects of anti-stress rose (Rosa mutiflora) fruit extract yoghurts (RFEY-1.0, RFEY-3.0, RFEY-5.0 containing with 1.0, 3.0 and 5.0% of rose fruit extract) were tested for the anti-stress effects. ICR male mice (20$\pm$2 g) were fed with basic experimental diets and given free access to water containing these ingredients for 18 days. Psychological stress and sociopsychological stress exposed by foot-shock for 1 hour (10 sec duration at intervals of 120 sec) every day for 3 days. RFEY-1.0, RFEY-3.0, RFEY-5.0 groups in the sociopsychological stress resulted in a significant decrease of 11.7%, 16.0% and 24.7% in plasma corticosterone (CS) secretion compared with psychological stress (control group). Noradrenaline (NA) secretions in the brain were significantly increased 15.6%, 25.0% and 40.8%, respectively, in RFEY-1.0, RFEY-3.0, RFEY-5.0 groups compared with control group. MHPG -SO$_4$ (3-methoxy-4-hydroxy-phenylethyleneglycol sulfate) levels in the brain resulted in a marked decreases of 17.0%, 25.3% and 28.4%, respectively, in RFEY-1.0, RFEY-3.0, RFEY-5.0 groups compared with control group. NA/MHPG-SO$_4$ ratios in the brain of RFEY-1.0, RFEY-3.0, RFEY-5.0 groups resulted in a significantly increase of 39.5%, 67.3% and 96.3%, respectively, compared with control group. These results suggest that rose fruit extract yoghurt may be tried to apply for human consumption such as sociopsychological stress.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.1
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• pp.120-131
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• 2015

This research aimed at understanding recognition of the park's community garden, public evaluation of it, and user awareness of the public enhancement plan. This was based on the problem that arose in the park community garden as public awareness research along with community garden cultivation participation within the urban park. In order to compare recognition differences along with community garden cultivation participation, the researcher conducted an analysis by dividing research participants into a cultivation participant group and non-participant group. As a result first, the cultivation participant group positively recognized the necessity of the community garden compared to the non-participant group. However, they recognized the community garden as a space for private profit, which threatened the public aspect of the park. Second, as a result of evaluating community garden publicness, the non-participant group which was alienated from community garden use, had a negative opinion about the community garden. Third, as a result of researching awareness of the community garden distribution method and consumption to promote publicness of the community garden, the cultivation participant group recognized the community garden as a space for private profit. Therefore, it is necessary for both groups to be aware of the public value of the community garden among the park users for sustainable management and operation. The significance of this research is the direction in the aspect of users to form, manage and operate the community garden in the urban park without damaging publicness of the park or conflicting between the function of the park and the function of the community garden. Henceforth, the researcher expects that this research can be utilized to maintain publicness of the park in respect of formation of the community garden in the park and management and operation.