• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.367-375
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• 2011

Succinic acid ester derivatives have been used as additives for the base oil of metal working fluids and pressure working oils. In this paper, a series of succinic acid alkyl half-esters were synthesized with over 97% yields by ring-opening reaction of succinic anhydride and fatty alcohol and were soluble in 100 N base oil within 1 wt% concentration. The structures and purities of ester derivatives were confirmed by $^1H-NMR$ and FT-IR spectrum and GC analysis. Anti-corrosion properties of the esters in sea water were evaluated through ASTM D665 method and weight loss method and compared to that of succinic alkyl esters without carboxylic acid group in the molecule. As the results, anti-corrosion properties of succinic acid alkyl half-esters with carboxylic acid group were better than those of succinic acid alkyl esters without carboxylic acid group. And, Anti-corrosion properties of the esters with a shorter alkyl chain of high concentration showed better performance than those with longer alkyl chain of low concentration. Inhibition efficiency % (IE%) of the esters was over 95% in the concentration of 80 ppm and corrosion rate (CR) was below 0.3 mm/year at the same concentration. Thus, the corrosion properties of succinic acid alkyl half-esters result from the carboxylic acid groups in molecules.

• Journal of Engineering Education Research
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• v.15 no.4
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• pp.21-25
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• 2012

In this paper, the purpose and overview of the "Frontier Leadership Program for Engineering Students through Joint Participation of Higher Education and the Industrial Sector" (FLC: Frontier Leadership Course) in Gunma University is reported together with our achievements during the last three years. The purpose of this special educational program is to promote and educate selected students who are highly motivated to learn science & mathematics and to become an active leader in industrial sectors or research institutes. The activity can be divided into two categories: "Student-Proposed Stream" and "Advanced Research Stream". These activities were found to be useful to cultivate student's leadership and global communication ability. Furthermore, most of the FLC students cultivated the excellent academic performance and five students among them will be allowed to skip their fourth undergraduate year and enter directly into our graduate school.

• Applied Biological Chemistry
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• v.40 no.5
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• pp.438-441
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• 1997

The relatedness of naturalized Bradyhizobium japonitum populations with soil physico-chemical characteristics as affected by paddy rice-upland soybean rotation cropping with conventional and none fertilization in Chilgog clay loam soils were determined as follows. The populations of B. japonicum in soils were increased from about $10^1$ in continuous paddy upto $10^1cells/g.soil$ only in one-year rotation of upland use with soybean cropping. Compared to the densities in plots of conventional fertilization, those in none fertilization were high ranging from 1.9 to 10 fold in 2-year upland use rotation and both in 3-year upland use rotation and 4-year upland use, respectively. The populations were positively correlated with soil organic matter $contents(r=0.83^*),\;Ca/K(r=0.74^*),\;and(Ca+Mg)/K(r=0.72^*)$ and were negatively correlated with soil $hardness(r=-0.73^*)$. And the soil populations increased by paddy-upland rotation resulted in superior symbiotic potentials to those in continuous paddy use in terms of nodule mass, nitrogenase activity, and soy-bean shoot dry weight.

• Journal of the East Asian Society of Dietary Life
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• v.6 no.1
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• pp.17-31
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• 1996

In order to reinforce and develop major courses in dietitian producing department, this study analysed and compared the courses of Food Science and Nutrition-related studies at 4-year and 2-year college. Results of the study are as follows: 1. There is no difference In the number of major courses provided by universities(33.2 courses) and junior colleges(32.6 courses), and universities(103) showed higher than junior colleges(79.9) with respect to total credit of courses. 2. Food Chemistry had highest credit(universities=1,532, junior colleges=1,037), while Nutrition Education had lowest credit (universities= 143, junior colleges=99) in the distribution of courses by way of major or classification. 3. The number of courses provided by universities and junior colleges was similar by way of minor classification. Especially, courses related to Food Chemistry showed highest frequency (universities=15, junior college=11) and percentage of credit (universities=32.6 junior college=34.3%), while courses related to Nutrition Education were one subject and percentage of credit was 3.0%. 4. Compared to percentage of the number of questions occupied in national qualifying examination for dietitians, the percentage of the number of credit provided by courses programs is higher in Biochemistry(universites 10.6%, junior colleges 7.5%) and Food Chemistry and Principles of Cooking(universites 27.0%, junior colleges 25.2%), but is lower in Diet Therapy(universites 7.6%, junior colleges 6.7%) and Nutrition Education(universites 4.9%, junior colleges 4.8%)

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.237-244
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• 2024

We studied the effects on their academic achievement of chemistry II and advanced chemistry subjects of science high school students according to the type of class (face-to-face and non-face-to-face). The subjects of this study were 195 first-year students of G Science High School located in Gyeongnam. The average scores of Chemistry II and Advanced Chemistry in non-face-to-face classes in 2020 and face-to-face classes in 2021 were compared and analyzed. As a result of comparing and analyzing the academic achievement according to the class type, students' grades in Chemistry II and Advanced Chemistry were higher in non-face-to-face classes. In the comparison of academic achievement by level according to class type, Chemistry II showed higher average grades in non-face-to-face classes as the lower level were, and in advanced chemistry, the higher the upper grades in non-face-to-face classes. In addition, in terms of the effect of changes in class form on the upper and lower 10% levels of academic achievement of Chemistry II, the upper 10% showed high grades in face-to-face classes and the lower 10% in non-face-to-face classes. On the other hand, in advanced chemistry, the average grade of non-face-to-face classes was higher than that of face-to-face classes in the top 10%, and the average grade of face-to-face classes was higher than that of non-face-to-face classes in the bottom 10%. Through these results, it was found that in the teaching-learning of science high school students, instructors need to design and treat teaching-learning appropriate to the level of academic achievement.

• Journal of the Korean Chemical Society
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• v.57 no.6
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• pp.778-788
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• 2013

The purpose of this study was to examine the change of the beginning science teachers' perception change through the mentoring program. Participants in this study were four mento-teachers, one university professor, two teachers in doctor, two teacher in doctor's or master's course, and four mentee-teachers who had less than three years teaching experience. We performed five times one to one mentoring for a year. We collected data such as video recordings of mentee-teacher's classes, lesson plans, recording of one to one mentoring and transcription, mento and mentee journals, preliminary-interim-post interview and transcription, and RTOP class observation report. Based on the result of this study, five times mentoring over a year changed mentee-teacher's perception and their teaching practice.

• Korean Journal of Ecology and Environment
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• v.42 no.4
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• pp.487-494
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• 2009

We compared spatial and temporal variations of water chemistry between high-flow year ($HF_y$) and low-flow year ($LF_y$) in an artificial lentic ecosystem of Daechung Reservoir. The differences in the rainfall distributions explained the variation of the annual inflow and determined flow characteristics and water residence time and modified chemical and biological conditions, based on TP, suspended solids, and chlorophylla, resulting in changes of ecological functions. The intense rainfall and inflow from the watershed resulted in partial disruption of thermal structure in the metalimnion depth, ionic dilution, high TP, and high suspended solids. This condition produced a reduced chlorophyll-a in the headwaters due to low light availability and rapid flushing. In contrast, reduced inflow and low rainfall by drought resulted in strong thermal difference between the epilimnion and hypolimnion, low inorganic solids, high total dissolved solids, and low phosphorus in the ambient water. The riverine conditions dominated the hydrology in the monsoon of $HF_y$ and lacustrine conditions dominated in the $HF_y$. Overall data suggest that effective managements of the flow from the watershed may have an important role in the eutrophication processes.

• Journal of the Korean Chemical Society
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• v.61 no.6
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• pp.378-387
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• 2017

In this study, we analyzed the causes of decrease in the number of students taking Chemistry ? in the College Scholastics Ability Test (CSAT) by analyzing the adequacy of the Chemistry I question in the CSAT and the recognition survey of students and teachers about the Chemistry I choice. We analyzed some questions in Chemistry I of the CSAT from the year 2014 to 2016. The questions were analyzed to determine whether they were appropriate to the curriculum content, achievement standard, and achievement level. The target of the survey for perception was 452 senior high school students and 68 science teachers. The result of the study showed that the questions in Chemistry I are somewhat difficult compared to the depth and achievement level required by the curriculum, and it also requires mathematical thinking ability. Students recognized the mathematical thinking and complex mathematical skills are needed to solve problems in Chemistry I. Teachers also thought that the choice of Chemistry I is unfavorable in aspect of meeting the minimum academic ability standard, and accordingly, they did not actively recommend students to take Chemistry I. Moreover, most of the teachers recognized that it is necessary to improve the direction of writing questions for Chemistry I. Therefore, setting questions that can be solved using chemical knowledge, not mathematical ability need to be addressed.

• Korean Journal of Environmental Agriculture
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• v.23 no.3
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• pp.178-184
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• 2004

Tolclofosmethyl (TCFM) is heavily and annually applied to the turf soils of most golf courses in Gyeongju to control the fungi known to cause the disease brown patch. The soil samples used for the experiment was collected three weeks after the annual application at the end of May in the year 2002. The preliminary results obtained from this study demonstrated that the repeated field annual applications of TCFM to the turf soils of a golf course located in Gyeongju city in the southern area of Korea showed the enhanced degradation of the parent compound TCFM, especially in the surface ($0{\sim}15\;cm$) soil rather than the shallow subsurface ($15{\sim}30\;cm$) and deep subsurface ($30{\sim}45\;cm$) soils, compared to the corresponding surface ($0{\sim}15\;cm$) and shallow and deep subsurface ($15{\sim}30\;cm$ and $30{\sim}45\;cm$) soils of the untreated plot. It appears that microorganisms in the soil may be involved in the enhanced degradation of TCFM.

• Safety and Health at Work
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• v.13 no.1
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• pp.86-92
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• 2022

Background: A laboratory where chemicals are handled can be considered a hazardous environment, and hence, prudent practices should be strictly enforced. If not, deadly accidents and incidents could occur due to a lack of safety practices and poor safety culture. The purpose of this study is to analyze the existing safety culture and propose potential recommendations to enhance the level of safety education in the chemical laboratories in the Western Province of Sri Lanka. Methods: A survey questionnaire was administered among the laboratory supervisors of the chemical laboratories in the Western Province of Sri Lanka in 2019. Results: Even though 80 surveys were distributed among prospective participants, only 46 surveys were submitted, which is 58% of the response rate. Most of the individuals who participated in the survey were females below 35 years old, and approximately 96% of the participants had at least one year of working experience in the same laboratory setting. The majority considered safety as an important factor that requires further improvements with third-party safety inspections; however, 54% of the respondents mentioned that those inspections were conducted by the employees from their laboratory. Conclusion: From the study, it has been discovered that employees have knowledge of safety culture to a certain extent. A significant percentage (83%) of participants believed that further safety measures are required for a safer laboratory. However, the study revealed that the attitudes of some employees should be changed to have a better safety culture. Hence the authors would like to suggest having annual training sessions and well-formulated safety policies to improve the safety culture.