• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.149-149
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• 2009

Generally, Nafion ionomer is used in the polymer electrolyte fuel cell (PEFC) electrodes to achieve high power density. At the high temperature operation of PEFC, however, ionic conductivity of Nafion remarkably decreased due to the evaporation of water in Nafion polymer. Recently, many researchers have focused on using the Ionic Liquids(ILs) instead of water in Nafion polymer. ILs have intrinsic properties such as good electrochemical stability, high ionic conductivity, and non-flammability. Especially, ILs play a crucial role in proton conduction by the Grottuss mechanism and act as water in water-free Nafion polymer. However, it was found that the ILs was leached out of the polymer matrix easily. In this study, we prepared membrane electrode assemblies with various contents of ILs. The effect of ILs in the electrode of each designed was investigated by a cyclic voltammetry measurement and the cell performance obtained through a single cell test using H2/Air gases. Electrodes with different contents of ILs in catalyst layer were examined at high temperature and low humidified condition.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.921-924
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• 2000

The purpose of this paper is to investigate the effects of admixture such as AE water reducing agent and Flyash on properties of cement mortar for floor. As for the effects of AE water reducing agent kinds, fluidity and air content increase in order for melamine type, lignine type and naphtalene type. As Flyash contents increase, fluidity shows high, but air content shows decline tendency. compressive strength according to AE water reducing agent kinds increase in order for melamine type, lignine type and naphtalene type. As AE water reducing agent content increases, it shows to be decreased. As for the effects of Flyash, it retards at early age but at later age it gains high with increase of Flyash contents due to pozzanic reaction. Drying shrinkage shows to be docreased slightly with increase of AE water reducing agent.

• Journal of Environmental Health Sciences
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• v.20 no.4
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• pp.98-117
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• 1994

To provide data for the contents regarding environmental health (environmental hygiene, environmental pollution) in the textbooks of primary, middle and high schools, a total of 243 textbooks was analysed for two months from May, to July 31, 1993. Among the total 52844.50 pages, 1.65% was related to the environmental health, which account for 870.00 pages. In the textbooks by school level, the rate of the contents regarding environmental health in primary school was 1.63% (148.75 pages). that of middle school was 1.96% (243.25 pages) and that of high school was 1.53% (478.00 pages). The area of environmental hygiene was 0.24% (129.25 pages) and that of environmental pollution was 1.40% (740.75 pages) which is slightly high. In the field of environmental hygiene, the rate of the contents in the middle school textbooks was 0.53% which was the higher than that of the primary and high school textbooks. The rate of environmental pollution area was not significantly different by school level but the number of the pages was the higher at the high school than that of the primary and middle schools, which account for 428.8 pages. The contents related by the areas were as follows: 1. Contents related to environmental hygiene 1) Among environemtnal hygiene contents, the rate of housing sanitation was the highest as 0.14% (73.00 pages), that of air environment was 0.06% (33.00 pages) and that of water supply sanitation was 0.03% (17.25 pages). The portion of air environment was 5.00 pages in the primary school textbooks and that of housing sanitation at the middle and high schools was each 35.0 pages, 35.50 pages, which was the more than that of other fields. By school year, there was no contents related at the 1st and 2nd grades but were 4.75 pages at the 4th grade which were the more than those of other grades. At the 5th grade, water supply sanitation part was found but not air environment. Housing sanitation was found at the 3rd, 5th grades and insect or rodent control was at the 3rd, 4th, 5th, 6th grades. 2) In the middle school textbooks related to environmental health, 41.0 pages were included in the textbooks of pysical education, the highest number. The next was 19.5 pages in home economics, 2.8 pages in social studies and 3.00 pages in others. The contents of air environment were found in the textbooks of physical education and science, those of water supply and housing sanitation were in home economics and physical education and those of insect control were found 0.5 pages in home economics only. 3) In the high school textbooks, the highest number was 27.8 pages of home economics and the next was 11.5 pages of others, 7.8 pages of physical education, 2.0 pages of science and 0.3 pages of social studies. Air environment parts were included in the textbooks of science, physical education and home economics and water sanitation was in home economics, physical education and others. Housing sanitation was showed in home economics and social studies, on the other side the contents of insect or rodent control was found in home economics and physical education. 4) By the subjects related to environmental hygiene in the primary, middle and high school textbooks, 51.0 pages of home economics were the highest portion. It was also revealed that 49.5 pages of physical education, 14.5 pages of others, 13.5 pages of science and 0.8 pages of social studies were included. The number of 33.0 pages of air environment portion was distributed into 9.75 pages of science, 19.0 pages of physical education and 4.25 pages of others. Among 17.3 pages of water sanitation, 3.5 pages of home economics, 11.3 pages of physical education and 2.5 pages of others were included. Housing sanitation portions were 73.0 pages, which were distributed into 46.5 pages of home economics, 0.5 pages of social studies, 18.3 pages of physical education and 7.8 pages of others. 5) The number of photo, figure, illustration and table related in the primary school textbooks was 31. Among them, the number of photos was 21, that of figures or illustrations was 9 and that of table was 1. The number of 63 in the middle school textbooks was classified into 3 photos, 32 figures or illustrations and 28 tables. At the high school, the number of 56 was included 2 photos, 41 figures or illustrations and 13 tables.2. Contents related to environmental pollution 1) In the field of environmental pollution, the rate of water pollution was 0.39% (203.3 pages), that of air pollution was 0.31% (161.5 pages) that of soil pollution was 0.1% (57.3 pages), that of refuse disposal was 0.08% (40.3 pages) and others was 0.5% (278.5 pages) by school level, the rate of water pollution in the primary, middle and high schools was each 40.5, 48.0, 118.8 pages and that of air pollution was each 20.8, 38.3, 102.5 pages. 2) Environmental pollution areas were not inserted in the textbooks at the 1st grade of the primary school but foqnd 5.5 pages at the 2nd grade, 30.5 pages at the 4th grade, 36.3 pages at the 5th grade and a,9.5 pages at the 6th grade. Water pollution was included from the 2nd grade, air pollution and refuse disposal from the 3rd grade and soil pollution from the 5th grade. 3) In the middle school textbooks, environmental pollution was distributed into 90.25 pages of science, 42.8. pages of physical education, 20.5 pages of social studies, 19.5 pages of others and 4.0 pages of home economics. At the high school, the contents were found 191.3 pages in science, 119.3 pages in others, 88.5 pages in social studies, 28.5 pages in physical education and 1.3 pages in home economics. 4) By subjects of the primary, middle and high schools, the portion of environmental pollution was classified into 322.2 pages of science, 195.0 pages of social studies, 138.8 pages of others, 76.3 pages of physical education and 8.5 pages of home economics. Air and soil pollution parts were not found in the subjects of home economics. 5) The number of photo, figure or illustration and table related in the primary school textbooks was 218. Among them, the number of photos was 61, that of figures or illustrations was 149 and that of tables was 8. At the middike school, the number of 153 was distributed into 99 photos, 34 figures or illustrations and 20 tables. The number of 129 found in the high school textbooks was included 129 photos, 73 figures or illustrations and 100 tables.

• Journal of the Korean Home Economics Association
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• v.30 no.1
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• pp.99-113
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• 1992

This study was performed to investigate the effect of dietary protein and calcium levels on cadmium detoxication in rats. Seventy male Sprague-Dawley rats weighing 208 $\pm$ 19 g were blocked into 10 groups of 7 animals according to body weight. Five groups were fed 15% protein-0.6% calcium diet with 100ppm cadmium in drinking water for first 15days and the other 5groups fed same diet without cadmium in drinking water for same period and served as controls. After this 15-day intoxication period, each one of cadmium intoxication and control groups were fed each of 4 kinds of detoxifying diets different with protein(40%, 15%) and calcium(1.3%, 0.6%) levels without cadmimum in drinking water for following 15 days of detoxifying period. Results were summarized as follows: 1) Food intake, body weight gain, F.E.R. and weights of liver, kidney and femur were increased by detoxifying diets and high protein diet was most effective in weight gains of liver and kidney. 2) When cadmium and metallothionein contents of initial intoxication group and those of all detoxication groups were compared, cadmium and metallothionein contents in the liver were not changed, but those in kidney increased, and those in intestine decreased markedly. 3) Only dietary protein level affected cadmium and metallothionein distribution among organs, and cadmium contents of whole blood, liver, kidney and femur were lower in high protein diet, but metallothionein contents in liver and kidney were higher in high protein diet. 4) Gel filtration chromatogram showed that most of cadmium in the cytosol was bound to metallothionein fractions in high protein-high calcium group. Results obtained indicated that high protein diet was effective in cadmium detoxication by increasing the induction of metallothionein synthesis. But high calcium diet did not play a role in cadmium detoxication.

• The Korean Journal of Food And Nutrition
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• v.33 no.4
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• pp.390-398
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• 2020

The purpose of this study was to determine the contents of water-soluble vitamins B₁ (thiamine), B₂ (riboflavin), B₃ (niacin) and B₁₂ (cyanocobalamin) in seafood-based dishes by using the high-performance liquid chromatography with the ultra violet and fluorescence detector. The vitamin B₁, B₂, B₃ and B₁₂ contents were analyzed in 29 seafood-based dishes. The method validation was performed on the method to determine the linearity, accuracy, limits of quantification, limits of detection and precision for vitamin B₁, B₂, B₃ and B₁₂. An excellent linearity range (R²=0.999~1.000) in the calibration curve for the water-soluble vitamins was observed. All analytical methods for the water-soluble vitamins showed the acceptable accuracy (89.4~119.7% recovery) and the precision (0.6~4.8% repeatability and 1.0~4.2% reproducibility). The highest content of vitamin B₁ was 2.646 mg/100 g in the kkongchi-jorim, and the highest contents of vitamin B₂, B₃ and B₁₂ were 0.370 mg/100 g, 10.971 mg/100 g, and 17.193 ㎍/100 g, respectively, in the kkongchi-gui. Our results provide reliable data on the contents of the water-soluble vitamins of seafood-based dishes in Korea.

• Korean journal of food and cookery science
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• v.4 no.1
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• pp.59-63
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• 1988

The changes of acidity, the content of alcohol-insoluble solid (AIS) and pectic substances of Kimchis which were prepared with various garlic contents and fermentation at $21^{\circ}C$ were investigated. Acidity and the content of water soluble pectin of Kimchis increased but the content of AIS and protopectin decreased during the fermentation. As the Kimchis contained high garlic contents compared with the Kimchis deleted garlic, acidity of those rapidly increased but the content of AIS of those slightly decreased with fermentation. In the case of Kimcltis contained high garlic contents, protopectin decreased and water soluble pectin increased with fermentation, but the amount of changes was small.

• Korean journal of food and cookery science
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• v.27 no.6
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• pp.745-754
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• 2011

To improve the textural properties of gluten free rice flour based products, the physicochemical and pasting properties of extruded non-waxy rice flours using extruder were investigated. The high yielding Tongil type rice variety, Hanarum was used. Hanarum rice flour was prepared by dry milling from soaked and dried rice grain. The operation conditions of twin screw extruder were 250 rpm of screw speed, $160^{\circ}C$ of barrel temperature, and 24, 27, and 30% of moisture content. Hanarum extruded rice flour (HERF) were lower in crude lipid and ash contents, but higher in crude protein than Hanarum rice flour (HRF). The color values of HERF showed significantly different (p<0.05) with different moisture contents. Water binding capacities, apparent amylose contents, and damaged starch of HERF were higher than those of HRF. Moisture contents affected water binding capacities of HERF. Solubility increased with increasing heating temperature and solubilities of HERF differed significantly (p<0.05). X-ray crystallinity was changed after extrusion cooking and that of HERF showed sharp peaks at $2{\theta}=18-20^{\circ}$. The pasting viscosities of HERF kept lower values (~ 10 RVU) constantly.

• Korean Journal of Environmental Agriculture
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• v.10 no.1
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• pp.59-66
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• 1991

This study was carried out to investigate the chemical characteristics of the rain water in rural, urban and industrial areas which are located in Kyongbuk province, namely. Songju, Kumi, Kimchon, Yongdok and Teagu. The experiments were sampled the rain by amount of rain water from July to August in 1989, and analyzed the pH. EC, $SO_4\;^{2-}$, $NO_3^-$ and $Cl^-$ contents in the rain water. The results are summarized as follows : 1. The acid rain showed at the begining rain water of all surveyed sites, but there were difference by sites, and particulary severe in Kumi. 2. The content of $SO_4\;^{2-}$ in rain water was high in urban and industrial area, such as Teagu, Kumi and Kimchon. 3. According to the increasing rain water amount, the pH in rain water was high, and the contents of other components were low. This phenomenon remarkably presented at higher concentration of components and earlier rain water. 4. The electric conductivity was high significantly positive correlation with contents of $SO_4\;^{2-}$, $NO_3\;^-$ and $Cl^-$ in rain water, and pH was high significantly negative correlation with contents of $SO_4^{2-}$ and $NO_3\;^-$ in rain water, respectively.

• Journal of the Korean Society of Food Culture
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• v.31 no.4
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• pp.348-356
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• 2016

The purpose of this study was to investigate the chemical contents (sugar, nitrogen, and amino acids) and sensory characteristics of traditional soy sauce according to three different methods. The samples were taken from four different periods (0, 20, 40, and 60 days after fermentation). Total sugar contents increased in all groups according to ripening period, and Gyupjang (G) showed the highest sugar content among the groups. Total nitrogen and amino acid contents of all groups increased after 60 days of ripening, and Gyupjang (G) and Gyupjang mixed with salt water (SG) had higher total nitrogen content compared to Chungjang (S) at the same period. The results from the sensory evaluation show that preferable sensory characteristics, such as color preferences, sweetness, umami taste, and overall preference, were significantly higher in Gyupjang (G) and Gyupjang mixed with salt water (SG) than in Chungjang (S). Preferable sensory characteristics had significantly high positive correlation with most amino acids, total nitrogen, and sugar contents, except for glutamine. Based on the significant difference in preferable sensory characteristics between Gyupjang mixed with salt water (SG) and Chungjang (S), Gyupjang mixed with salt water (SG) can be used to improve sensory characteristics. This research implies that adding salt water during the manufacturing Gyupjang process is advisable to yield high quality soy sauce.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.46-47
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• 2018

High performance concrete with low water-to-cement ratio has been widely used with increased demand of high rising buildings and huge scaled structures. Additionally, for high performance concrete, various SCMs are replaced to improve its performance from fresh state to hardened state. With the drawback of increased viscosity of the concrete mixture for high performance concrete, low-viscosity typed high range water reducer is the relatively new admixture. Therefore, as a goal of the research, under using various SCMs with wide range of content, the performance of low-viscosity typed high range water reducer was evaluated. Especially, in this research, the influence of low-viscosity typed high range water reducer on rheological properties including plastic viscosity and yield stress were assessed. As a result of the research, it is expected to provide a fundamental information of low -viscosity typed high ranged water reducer on high performance concrete with various conditions of SCMs.