• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.2
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• pp.287-292
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• 2014

The objectives of this study were to examine the effects of red clay-processed nano-materials (RCPM) on the quality characteristics of eel (Anguilla japonica). Both eels treated with RCPM and control were farm-raised under identical environments and were commercially processed. General components, texture, nutrients, antioxidant activities, and sensory analysis were performed. RCPM-treated eels showed significantly higher DPPH radical scavenging activities and FRAP values than the of control, indicating higher antioxidant activities of eels raised by RCPM. The amounts of niacin and tocopherol in RCPM-treated eels were higher than those of the control. For analysis of freeze-thaw stability, RCPM-treated eels showed more stable texture over freeze-thaw three treatment cycles. Descriptive panelists perceived eels raised by RCPM to be less oily than the control. Overall, RCPM exhibited positive effects on the quality of farm-raised eels. Therefore, RCPM would be of benefit to produce high value-added eels of premium quality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.5
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• pp.732-738
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• 2015

Quality characteristics of Korean cabbage treated with red clay-processed materials (RCPM) were evaluated. Two different types of RCPM treatments including a control were applied for the cultivation of cabbage. General components, nutrients, antioxidant activities, textures, and sensory evaluation were assessed. For the nutrition components analysis, RCPM-treated cabbage showed higher contents of potassium and riboflavin along with lower content of sodium compared to the control. RCPM-treated cabbage exhibited higher total polyphenol contents than those of the control, indicating higher antioxidant activities. For the textural analysis under refrigeration over 4 weeks, RCPM-treated samples showed more stable textures based on higher hardness values than the control and RC. Results of this study indicate that RCPM would be of benefit to produce high-value added cabbage of premium quality.

• Korean Journal of Organic Agriculture
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• v.28 no.2
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• pp.209-221
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• 2020

Highbush blueberries (Vaccinium corymbosum), 'Duke', 'Bluecrop', and 'Elliott', were applied with ground cover mulch systems to evaluate bush growth and fruit characteristics. Soil temperature variation was lower in the woodchip mulching plot. Therefore, CEC, soil pH, phosphate, mineral ions were not significantly different among mulching materials. The number of main stem was higher in woodchip > sawdust > rice husk > plastic film mulching plot, respectively. Total shoot number was also higher in organic mulching plots than in plastic film plot. However, total shoot number was not significantly different among the organic mulching plots. Fruit weight was the highest in the woodchip mulching plot of all blueberry cultivars, however, soluble sugar content, organic acidity, fruit firmness were not significantly different in mulching materials. Yield was higher in organic mulching plots than in plastic film plot in all blueberry cultivars. Especially, yield per shrub of woodchip plots was the highest about 3.6 kg in 'Duke', 2.7 kg in 'Bluecrop', and 2.6 kg in 'Elliott'. Furthermore, correlation of main stem number and yield was highly significant (r² = 0.8413). Therefore, woodchip mulching is expected to be an eco-friendly method to increase the number of stems and the yield of blueberries.

• Korean Journal of Organic Agriculture
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• v.25 no.2
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• pp.445-460
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• 2017

This study was carried out for three years from 2013 to 2015 to investigate the actual condition of pest control of domestic persimmon organically cultivated farmers, to select environment - friendly pest control materials for major pests, and to conduct field test of established control system. The main cultivated cultivar of the reader farmer of organic cultivation was "Buyou" and sprayed organic agricultural material 9~17 times per year for pest control. The most harmful pests were anthracnose, bugs, persimmon fruit worm, and scales, etc. The control materials used were organic lime sulfur mixture, red clay sulfur, emulsifier, bordeaux solution, and self-made plant extracts using garlic, ginkgo nut and pine tree. The effective materials for controlling anthrax were lime sulfur mixture and red clay sulfur. Garlic oil + citronella emulsion, shrubby sophora seed extract + tea extract was effective to control Riptortus clavatus and Euproctis subflava. When installed 60 ea per 10a of mating disruption trap in a sweet orchard, the fruit setting rate was improved by 30%. The results of field test of control system to control 10 times a year in organically grown persimmons were able to harvest fruit of 70.7%. However, since any kinds of pesticides can not be sprayed during the harvest season in September and October, the damaged by bugs did not decreased, and further research is needed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.5070-5077
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• 2014

Many countries in the world have protected their native plants and utilized them as industrial materials in each country. In this aspect, it is increasingly important to develop cosmetics materials using native plants in Korea. Cosmetic materials have been developed with niche plants, such as Campanula takesimana Nakai, Dianthus superbus, Aster spathulifolius in Ullengdo, in which a specific plant distribution by distinct climate and environment was present. Water and ethanol extractions were performed from the calluses of Campanula takesimana Nakai, Dianthus superbus, Aster spathulifolius. HPLC analysis revealed different compositions and functions of effective elements in each ethanol extract. For example, all types of ethanol extracts showed an ability to heal wounds. In particular, the expression of the inflammation-related gene, COX-2, was decreased in response to the ethanol extracts of Dianthus superbus. These results indicate that the ethanol extracts from niche plants' calluses in Ullengdo are natural and environmentally-friendly compounds, and can be used as medical supplies associated with anti-inflammation and wound healing.

• Journal of Science Education
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• v.34 no.1
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• pp.33-46
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• 2010

The purpose of this study was to find out the image as science teachers recognized by pre-service science teachers. The data was collected from 312 pre-service science teachers from Kyungpook National University in Daegu and participants were asked to write about the image of science teachers they liked most and least in their secondary school years freely. The result of this research was as follows. The image as science teachers categorized 2 factors: science instructional situation, image of science teacher. Each factor was subdivided into more detailed ones. First of all, 'science instructional situation' category subdivided into lesson style, teaching-learning materials, teaching methods, and class atmosphere. In lesson style, 'experiment' and 'observation' gained the most favorable comments, and questioning-answering gained the least. In teaching-learning materials, print materials such as handouts, worksheets, reports were the most liked, and 'writing on the blackboard' was the least liked. In teaching methods, the 'detailed and systematic explanation of the theory and concepts' was preferred to rote learning and memorization lacking explanation. In class atmosphere, friendly and free atmosphere was the most preferred, and uncomfortable, boring one was the least preferred. Secondly, in 'image of the science teachers' category and 'quality as the teachers' sub-category, thoughtful and considerate teachers who respect students' personality was the most preferred. On the contrary, they didn't prefer teachers who were indifferent and humiliated students. Finally in 'characteristics of the teachers' sub-category, the participants liked clear, energetic voice, and mild expression, and they didn't like formal style, overly fancy clothes, etc. Based on the result of this study, more empirical study on the teachers' image is needed, and the thoughts of educational administrators, students, parents, and teachers should be reflected because an undesirable teacher can be advised and get opportunity to be a better teacher.

• Applied Chemistry for Engineering
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• v.31 no.5
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• pp.453-466
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• 2020

As the demand for eco-friendly energy increases to overcome the energy shortage and environmental pollution crisis, hydrogen economy has been proposed as a potential solution. Accordingly, an economical and efficient hydrogen production is considered to be an essential industrial process. Research on applying hydrogen separation membranes for H₂/CO₂ separation to the production of highly concentrated hydrogen by purifying H₂ and capturing CO₂ simultaneously from synthetic gas produced by gasification is in progress nowadays. In high temperature environments, the membrane separation process using glassy polymeric membrane with H₂ selectivity has the potential for CO₂ capture performance, and is an energy and cost effective system since polybenzimicazole (PBI)-based separators show excellent chemical and mechanical stability under high-temperature operation conditions. Thus, the development of high-performance PBI hydrogen separators has been rapidly progressing in recent years. This overview focuses on the recent developments of PBI-based membranes including structure modified, cross-linked, blended and carbonized membranes for applications to the industrial hydrogen separation process.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.3
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• pp.304-311
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• 2014

In this study, to apply hydrogen energy to ship engine and to generate effective hydrogen production, we investigated the effects of high temperature $H_2SO_4$ feed rate and cooling water rate to pump parts with fixed frequency needed to reciprocate motion and a simulation was conducted at each condition. In the fixed frequency and cooling water inlet flow rate of 0.5 Hz and 3.9 kg/s, we changed the high temperature $H_2SO_4$ flow rate to 47.46 kg/s (it is 105 % of 45.2 kg/s), 49.72 kg/s (110 %), and 51.98 kg/s (115 %). Also, at 0.5 Hz and 45.2 kg/s of frequency and high temperature $H_2SO_4$ flow, the thermal hydraulic analysis was performed at the condition of 95 % (3.705 kg/s), 90 % (3.51 kg/s), and 85 % (3.315 kg/s). In overall simulation cases, the physical properties of materials are more influential to the temperature increase in the pump part rather than the changes on the feed rate of high temperature $H_2SO_4$ and cooling water. A continuous operation of pump was also capable even if the excess feed of high temperature $H_2SO_4$ of about 15 % or the less feed of cooling water of about 15 % were performed, respectively. When the increasing feed of high temperature $H_2SO_4$ of up to 5 %, 10 %, and 15 % were compared with base flow (45.2 kg/s), the deviation of time period rose to a certain temperature and ranged from 0 to 4.5 s in the same position (same material). In case of cooling water, the deviation of time period rose to a certain temperature and ranged from 0 to 5.9 s according to the decreasing feed changes of cooling water at 5 %, 10 %, and 15 % compared to a base flow (3.9 kg/s). Finally, the additional researches related to the two different materials (Teflon and STS for Pitch and End-plate), which are concerned about the effects of temperature changes to the parts contacting different materials, are needed, and we have a plan to conduct a follow-up study.

• Journal of Adhesion and Interface
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• v.11 no.2
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• pp.41-49
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• 2010

Furan-containing epoxide monomers (8, 9) were designed and synthesized as carbon-neutral, environment-friendly adhesion material. Bicyclic skeleton were constructed using the Diels-Alder reaction of furan and methyl acrylate, both readily accessible starting material from a biomass via bio-refinery process. After reduction of ester functionality, resulting hydroxyl moieties were coupled to epichlorohydrin to provide the epoxy-functionalized furanic monomers (8, 9). The structure of new furanic monomers was confirmed by $^1H$ and $^{13}C$ NMR spectroscopy. As UV-curable monomers, basic properties such as UV curing time and the extent of UV curing were evaluated by photo DSC. Photo-curing shrinkages were measured by linear variable differential transformer transducer (LVDT) and the effect of molecular structure on shrinkage was considered. In addition, new synthetic compounds showed the shear strength over 3 MPa when they were photo-cured between polycarbonate plates, which indicates these compounds are feasible to use as photo-curable adhesive materials.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.5
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• pp.218-224
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• 2015

Recently, removing methods of red tide has been attempted by filtering the organisms using the ceramic porous bodies. However, the marine biofouling could be developed on the surfaces of porous ceramic body after use for more than one month, and it might decrease the function of the specimen. In this paper, a method of inhibiting marine biofouling by changing the physical properties or surface-modification of ceramic porous body was studied. After experiment with six different ceramic porous bodies, it was found that the specimen of lower porosity and water absorption showed the least amount of biofouling. In addition, by increasing the surface roughness with silica particles bonded to the surface of specimen, the amount of biofouling caused by large marine life such as barnacle and mussel could be decreased. On the other hand, when the surface of specimen was coated and fused by glass powder, the amount of biofouling was rather increased. This might be due to eluted inorganic ions from the glass which can promote the growth of the microorganism. In conclusion, the environmental-friendly methods to reduce the amount of marine biofouling, such as controlling the physical properties and the surface roughness of the porous ceramics, can be possible without the use of dangerous substances. So it is expected for the results obtained to be applicable to a marine structure.