• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.1
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• pp.92-99
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• 2017

People have become more interested in fiber intake due to the rise of noncommunicable diseases such as hyperlipemia and abdominal obesity. This study was carried out to develop dacquoise incorporating different amounts of rice bran dietary fiber (5%, 10%, 15%, and 20%). Dacquoise characteristics such as viscosity, specific volume, moisture content, color, and texture were measured. Consumer acceptance and check-all-that-apply on characteristics of dacquoise with rice bran dietary fiber were observed. Increasing amounts of rice bran dietary fiber resulted in increasing viscosity of batter as well as higher specific volume, lightness, and hardness of finished product. On the contrary, yellowness and redness of dacquoise increased as the amount of rice bran dietary fiber increased. While there was no effect of rice bran dietary fiber on moisture content (range of 26.53~25.35%). According to the consumer acceptance test, dacquoise with 5% of rice bran dietary fiber showed the highest liking score in color and overall acceptance (5.9 and 5, respectively). The findings from the principle component analysis of principle component (PC) 1 (71.04% explanation) showed that as rice bran dietary fiber increased, texture of the product got drier, and consumers described the product with 20% rice bran dietary fiber as cotton mouth and 5% rice bran dietary fiber as sticky. PC2 (16.54% explanation) demonstrated 5% and 10% rice bran dietary fiber, and dacquoise had nutty and soybean notes while 15% and 20% rice bran dietary fiber dacquoise had flour, bitter, and salty flavors. Based on these results, the optimum addition level of rice bran dietary fiber for dacquoise is 5%.

• Journal of the Korean Electrochemical Society
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• v.20 no.4
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• pp.67-74
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• 2017

Layered Ni-rich NCM cathode materials $Li[Ni_xCo_{(1-x)/2}Mn_{(1-x)/2}]O_2$ ($x{\geq}0.6$) have advantages of high energy density and cost competitive over $LiCoO_2$. The discharge capacity of NCM increases proportionally to the Ni contents. However, there is a problem that it is difficult to realize the stable electrochemical performance due to cation mixing. In this study, synthesis conditions for the layered Ni-rich NCMs are investigated to achieve deliver the ones having good electrochemical performances. Synthesis parameters are atmosphere, lithium source, synthesis time, synthesis temperature and Li/M (M=transition metal) ratio. The degree of cation mixing gets worse as the Ni content is increased from $Li[Ni_{0.6}Co_{0.2}Mn_{0.2}]O_2$ (NCM6) to $Li[Ni_{0.8}Co_{0.1}Mn_{0.1}]O_2$ (NCM8). It is confirmed that higher level of cation mixing affects negatively on the electrochemical performance of NCMs. Optimum synthesis conditions are explored for NCMx (x=6, 7, 8) in order to reduce the cation mixing. Under optimized conditions for three representative NCMx, a high initial discharge capacity and a good cycle life are obtained for $180mAh{\cdot}g^{-1}$, 96.2% (50 cycle) in NCM6, $187mAh{\cdot}g^{-1}$, 94.7% (50 cycle) in NCM7, and $201mAh{\cdot}g^{-1}$, 92.7% (50 cycle) in NCM8, respectively.

• Korean journal of applied entomology
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• v.57 no.2
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• pp.57-64
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• 2018

The fungus gnat, Bradysia difformis, has been recognized as an important pest of greenhouse crops. There is a need for research on the control of the fungus gnat. However, it is difficult to obtain many generations of the fungus gnat for several kinds of research. Indoor propagation is a very useful method for obtaining enough individuals in cases where the need is for larvae in soil. This study was conducted to determine the optimum growing media and temperature conditions for rearing the fungus gnat in the laboratory. Under experimental temperature conditions, hatching, pupation, and eclosion rates were the highest at $20^{\circ}C$. The developmental period of the fungus gnat was shortened with higher temperatures. The greatest number of eggs was an average of 144 at $20^{\circ}C$. Using different types of larvae growth media, the highest hatching rates were 84.7 and 84.4% in water agar and potato disks, respectively. The larval period was the shortest, at 14.7 days, when grown on potato disks. The highest pupation and eclosion rates were 85.2 and 82.6% on potato disks, respectively. The highest number of eggs was an average of 125.6 on potato disks. Regarding the effects of different growth media on the eclosion rate of B. difformis, the highest eclosion rate was 88.4% on the soil mix, and was 50% on oatmeal, 25% on shredded potato. The results of four different inoculation levels of larvae on eclosion rate of B. difformis showed that the highest eclosion rate was 84.7% for 1,000 larvae. The eclosion rate was shortened with a higher number of larvae inoculated/cage. In the growth medium used, 3,000 eggs were better for the initial level of inoculation, showing a relatively high emergence rate and short developmental period. Mass rearing procedures were explained in detail.

• KSBB Journal
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• v.24 no.1
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• pp.30-40
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• 2009

Statistical optimization of the production medium was carried out in order to find an optimal medium composition in itaconic acid fermentation process. Itaconic acid utilized in the manufacture of various synthetic resins is a dicarboxylic acid biosynthesized by fungal cells of Aspergillus terreus in a branch of the TCA cycle via decarboxylation of cis-aconitate. Through OFAT (one factor at a time) experiments, six components (glucose, fructose, sucrose, soluble starch, soybean meal and cottonseed flour) were found to have significant effects on itaconic production among various carbon- and nitrogen-sources. Hence, using these six factors, interactive effects were investigated via fractional factorial design, showing that the initial concentrations of sucrose and cottonseed flour should be high for enhanced production of itaconic acid. Furthermore, through full factorial design (FFD) experiments, negative effects of $KH_2PO_4$ and $MgSO_4$ on itaconic acid biosynthesis were demonstrated, when excess amounts of the each component were initially added. Based on the FFD analysis, further statistical experiments were conducted along the steepest ascent path, followed by response surface method (RSM) in order to obtain optimal concentrations of the constituent nutrients. As a result, optimized concentrations of sucrose and cottonseed flour were found to be 90.4g/L and 53.8g/L respectively, with the corresponding production level of itaconic acid to be 4.36 g/L (about 7 fold higher productivity as compared to the previous production medium). From these experimental results, it was assumed that optimum ratio of the constituent carbon (sucrose) and nitrogen (cottonseed flour) sources was one of the most important factors for the enhanced production of itaconic acid.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.2
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• pp.233-238
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• 2012

We prepared sponge cakes consisting of 1.5%, 3%, 4.5%, or 6% Omija powder. The specific gravity and viscosity of sponge cake batter were measured. Also, the moisture content, color, volume index, weight and texture of the sponge cake were determined. Consumer preference tests of the sponge cakes were also conducted. The viscosity of cake batter tended to decrease as the ratio of Omija powder increased. The specific gravity of the control batter was 0.41, and there was no significant difference between the control and the cakes baked with 1.5%, 3%, 4.5%, and 6% Omija powder. The moisture content and weight of the cakes were not significantly different between the control and those made with Omija powder. Hunter 'L,', 'a,' and 'b' values of the crust decreased significantly as the amount of Omija powder in the cake increased. Hunter 'L' and 'b' values of the crumbs were low in the cakes with Omija powder, while 'a' values were high. Hardness and fracturability did not show any differences between the cakes. Adhesiveness and resilience of the control were high. The control sample showed the highest sensory score in overall preference. However, cakes made with 1.5% Omija powder obtained the highest values in color, softness, and flavor scores. Omija powder flavor and astringency scores increased as the amount of Omija powder increased, and sweetness did not show any differences among cakes. Intensity scores of egg flavors significantly decreased as the amount of Omija powder increased. Sensory scores of off-flavor significantly increased as the amount of Omija powder increased. Based on the results, 1.5~3% should be recommended as the optimum level of Omija powder to be added for the preparation of sponge cake.

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.50-58
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• 1995

These studies were carried out to develop a system for non -destructive and continuous measurement of fresh weight and to analyse the growth response of leaf lettuce under the different nutrient solution and light condition with this system. The developed measurement system was consisted of four load cells and a microcomputer. The output from the system was highly positive correlation with the plant fresh weight above the surface of the hydroponic solution. The top fresh weight of plant could be measured within the error $\pm$ 1.0g in the range of 0 - 2000g. The top fresh weight of leaf lettuce increased 44 times at 18th day after transferring to the nutrient solution, and the maximum growth rate was observed at 13th day after transferring. The growth rate was 10.7- 29.6% per day during 18 days. Optimum concentration of the nutrient solution for the growth of lettuce was 1.4 - 2.2 mS/cm of EC level. When the light condition was changed from dark to light, the fresh weight was temporarily decreased, but the fresh weight increased under the opposite condition. Top fresh weight of leaf lettuce in the darkness normally increased within 12 hours after darkness treatment, and then slowly increased until 78 hours under continuous dark condition. After that times, the fresh weight began to decrease.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.1
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• pp.115-123
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• 1990

The purpose of this study was to examine the uses of coal ash as a type of construction material. The methods of examination were chemical anlysis, soil laboratory test and the soil vibration test. Materials used were coal ash obtained as a by-product from 5 thermal power plants in Yongdong, Yongwol, Sochon(anthracite coal) and in Samchonpo and Honam (bituminous coal). Over 70% of the coal ash consisted of silica and alumina. The fly ash grain size showed a uniform distribution from fine-sand to silt, and that of the bottom ash showed from sand to gravel. The specific gravity and density of the coal ash were low. The long term strength increased gradually due to the self-setting property resulting from pozzolanic activity. The shear strength was higher than that of general soil. Cohesion and optimum moisture content of anthracite coal ash were higher than bituminous coal ash, whereas the maximum dry density was higher in bituminous coal ash. The coal ash dynamic Young's modulous curve range was similar to that of general soil. Of the results from the soil vibration test by car-running, the size relative acceleration level in the ash pond was higher than that of natural ground, but the damping ratio was lower than that of natural ground near the ash pond. The coal ash has more advantageous engineering properties than general soil with particles of the same size. For example, the California Bearing Ratio of the bottom ash at both Yongdong and Yongwol was 77~137%. Therefore we expect that if further study is done, coal ash can be used as a construction material when reclaiming seashore, construction embankments, road construction, making right-weight aggregate, or as a general construction material.

• The Korean Journal of Food And Nutrition
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• v.24 no.3
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• pp.434-441
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• 2011

In this study, certain quality characteristics of kimbugak samples prepared with 2 different puffing methods, microwave oven and frying, and containing different levels of sea tangle powder(0, 2, 4, and 6%), were examined according to mineral content, moisture content, color values, photographic images, hardness and sensory evaluations. The mineral contents of Porphyra yezoensis were: K, 2,612.400 mg; Ca, 116.970 mg; Na, 486.099 mg; Mg, 297.800 mg; Fe, 9.636 mg; Mn, 1.614 mg; and Cu, 0.973 mg. And those of the sea tangle powder were: K, 5,115.000 mg; Na, 1,848.931 mg; Ca, 763.030 mg; Mg, 525.700 mg; Fe, 15.125 mg; Zn, 4.639 mg; and Mn, 0.146 mg. Moisture content was not significantly different among the samples of kimbugak puffed by the microwave oven and frying. For the color of the kimbugak made with the microwave oven or frying, L values decreased as the level of sea tangle powder increased. Color a and b values were lowest in the control group. The color values(L, a, and b) of the kimbugak puffed by frying were higher than those made using the microwave oven. The hardness of the kimbugak samples puffed using the microwave oven were not significantly different according to levels of sea tangle powder, and in the kimbugak puffed by frying, the lowest hardness was in the sample with 6% sea tangle. In sensory evaluations, color and crispness were not significantly different among the samples. The flavor scores of the 4% and 6% samples puffed by frying were higher than those of the kimbugak samples puffed using the microwave oven. The overall acceptability of the kimbugak puffed by frying and containing 6% sea tangle powder was the highest. In conclusion, 4 and 6% sea tangle powder would be considered optimum amounts for kimbugak puffed by frying.

• Korean journal of food and cookery science
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• v.20 no.5
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• pp.468-479
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• 2004

This study was conducted to investigate factors affecting the bone density of university students in the Seoul area. Data for food habits, and dietary and health-related behavior was obtained by self-administered questionnaires. BQI (bone quality index) of the subjects was measured by a Quantitative Ultrasound (QUS). The results are summarized as follows. The average height, weight, BMI and osteopenia percentage were 175.4cm, 69.3kg, 22.5 and 15.6% for male students, and 161.5cm, 55.9kg, 21.7 and 34.1%, for female students, respectively. The mean BQI of the subjects was 110.25 (range 60.7 ～ 176.8) in male students and 90.64 (range 52.9 ～ 137.5) in female students. Height and weight were significantly related with BQI in the female group but the relationship with BMI was not significantly related with bone density in either group. BQI was positively affected by nutrition supplement in the male student group. One-side eating, diet, and intake of milk and instant food were not significantly related with BQI in males or females. The results of this study revealed that desirable food habits, dietary behavior and health-related lifestyle may have a beneficial effect on bone density. There should be established a practically and systematically organized nutritional education on optimum body weight, good eating habits, weight bearing exercise and intakes of good quality nutrient for higher bone density level.

• The Journal of the Petrological Society of Korea
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• v.10 no.3
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• pp.179-189
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• 2001

The determination of trace concentration of U, Th and Pb was carried out for chemical dating of zircon and monazite by electron microprobe. Detection limit and error range should be considered to measure characteristic X-rays of M-line from those minerals, which are low in the ionization of atom and low peak intensity in the spectrum. The element of U, Th and Pb were simultaneously measured with 3 spectrometers equipped with PET crystal to reduce a total counting time and error due to drift of instrumental operating condition. Detection limit could be improved from increase of the peak/background ratio through adjusting pulse height analyzer about 1000 mv baseline. Under permissible maximum analytical conditions, theoretical detection limit of U, Th and Pb is down to 30 ppm (99% confidence level). The analytical result was maintained at a relative error $\pm$10% ($2{\sigma}$) in 800 ppm Pb, $\pm$5% ($2{\sigma}$) in 2330 ppm U and $\pm$10% ($2{\sigma}$) in dating from a single measurement of zircon at 15 keV and 100 nA. However, for the precise dating of zircon and monazite, if it is considered a 3 $\mu\textrm{m}$ spatial resolution, <100 ppm ($3{\sigma}$) detection limit and <$\pm$10% ($2{\sigma}$) relative error, optimum analytical conditions are given as 15~20 keV accelerating voltage, 100~200 nA beam current and 300~1200 sec total counting time. To reduce material damage by high current, there is need to be up to 3~5 $\mu\textrm{m}$ of electron beam diameter, or to use arithmetic average of multiple measuring at a shorter counting time. A younger or relatively low concentration rocks can be dated chemically by lower detection limit and improved precision resulted from increase of current and measuring time.