• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.1
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• pp.104-108
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• 2006

Effect of gamma irradiation on the softening of dried fernbrake at different moist-heating conditions was investigated. Dried fernbrake packaged in controlled atmosphere $(CO_2\;25\%,\;N_2\;75\%)$ was irradiated up to 7 kGy with $\gamma-ray$. Hardness of dried fernbrake was significantly decreased at the irradiation dose of above 5 kGy. Hardness of cooked fernbrake was significantly decreased with increasing irradiation dose level as well as heating temperature and time. $DT_{50}$ value (The heating time required to reach the $50\%$ reduction of hardness) for irradiated fernbrake was shortened according to dose level as well as heating temperature and heating time: $DT_{50}$ value of control: 23 min, 5 or 7 kGy: $2.2\~5.0$ min at $60^{\circ}C$. Also, the activation energy for softening of irradiated fernbrake ($1.85\~1.88$ kcal/mole for $5\~7kGy$) decreased compared to control (4.30 kcal/mole). Moisture content, swelling and rehydration rate of gamma irradiated fernbrake during moist heating increased according to the irradiation doses. Sensory results showed that scores of off-flavor and odor in irradiated fernbrake upto 7 kGy were not significantly different from control. Based on these results, gamma irradiation was effective for the reduction of cooking time and the activation energy for softening of dried fernbrake with increasing dose levels.

• Journal of the Korea Institute of Building Construction
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• v.18 no.1
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• pp.25-31
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• 2018

In this study, the Controlled Low Strength Material (CLSM) was investigated to utilize the bottom ash and fly ash generated in the Circulating Fluidized Bed Combustor (CFBC). It was confirmed that the CFBC fly ash (CFBC-F) and CFBC bottom ash (CFBC-B) had an irregular particle shape through SEM measurement. According to the results of the hazard analysis, it was also confirmed that they were environmentally safe. In the case of mixing with CFBC-F, the unit quantity was increased. Regarding the rate of change of length, shrinkage in the range of -0.05~0.50% occurred in the air dry curing condition and expansion in the range of 0.1~0.6% in the sealed curing condition. Compressive strength was increased in the sealed curing condition compared to the air dry curing condition because there was enough moisture for hydration reaction in the long term. Therefore, the results of this study are likely be used as basic research data of mine filler materials.

• Magazine of the Korean Society of Agricultural Engineers
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• v.27 no.2
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• pp.57-71
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• 1985

The characteristics of compaction and unconfined compressive strength were investigated by mixing with lime to all soils adjusted by given percentages of two kinds of clays to sand to obtain the most effective distribution of grain size and the optimum lime content for soil stabilization. In addition, unconfined compressive strength and durability tested by adding of sodium metasilicate, sodium sulfate, sodium carbonate, sodium gydroxide and magnesium oxide to lime-soil mixture mixed with 8 percent lime to adjusted soil having the mixing percentage of 60 percent of cohesive black clay and 40 percent of sand by weight to get the effect and the optimum content of chemicals. The results obtained were as follows; 1.With the addition of more lime, the optimum moisture content was increased, and the maximum dry density was decreased, whereas the more the amount of clay and the less was the maximum drt density. 2. In the soil having more fine grain size the unconfined compressive strength was larger in the earlier stage of curing period, in accordance with the longer period, the mixing percentages of sand to clay showing the maximum unconfined compressive strength, on the basis of 28-day strength, were 60% : 40% (black clay) and 40% : 60% (brown clay) respectively. 3. The reason why the soil adjusted with black clay was remarkably bigger in the unconfined compressive strength than ones adjusted with brown clay for all specimen of lime-soil mixture was the difference in the kind of clay, the amount of chemical compositions the value of pH. Black clay was mainly composed of halloysite that reacted with lime satisfactorily, whereas the main composition of brown clay was kaolinite that was less effect in the enhance of unconfined compressive strength. Also the difference of unconfined compressive strength was because black clay was larger in the amount of composition of calcium oxide and magnesium oxide in the value of pH affecting directly on the unconfined compressive strength of lime-soil mixture than brown clay. 4. In the lime-soil mixture mixed with 8 percent of lime to soil that mixing percentage of sand to black clay was 60% : 40%, on the standard of 7-day strength, the effect of chemical was arranged in the order of magnesium oxide, sodium carbonate, sodium sulfate, sodium hydroxide and sodium metasilicate. 5. The optimum amount of chemical being applicable to the maximum unconfined compressive strength of lime-chemical-soil mixture was 1 percent by weight for air dry soil in the case of adding sodium carbonated and 0.75 percent on sodium hydroxide, the unconfined compressive strength was increased continuously with increase of the amount of chemical up to 2 percent of chemical content is the lime-chemical-soil mixture added sodium metasilicate, sodium sulfate and magnesium oxide. 6. It was considered that the chemical played and accelerant role of early revelation of strength because the rate of increase of unconfined compressive strength of all of lime-chemical-soil mixtures was largest on the 7-day cured specimen. 7. The effect of test on freezing and thawing after adding suitable amount of chemical on the lime-soil mixture mixed with 8 percent of lime to soil that mixing percentage of sand to black clay was 60% : 40% was arranged in the order of magnesium oxide, sodium carbonate, sodium sulfate, sodium metasilicate and sodium hydroxide.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.21-26
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• 2018

Thermoplastic starch (TPS) was prepared by mixing starch with glycerol as a plasticizer. The glycerol content ranged from 20 to 35 wt. % and TPS was prepared in a twin screw extruder. The shear viscosity, thermal and mechanical properties of the TPS were investigated. The viscosity of TPS exhibited typical shear thinning behavior: decreasing viscosity with increasing shear rate. The power index, n, increased with increasing glycerol content. This is because as the content of glycerol, a Newtonian fluid, increases, the viscosity behavior of the TPS becomes closer to that of a Newtonian fluid. The thermal behavior of TPS showed that starch and glycerol are miscible. In addition, when TPS was aged for more than one day at room temperature, TPS showed a partially miscible phase structure. The moisture absorbed into the TPS was assumed to change the phase behavior. The mechanical properties of TPS were found to be strongly dependent on the content of the plasticizer. Both the toughness and stiffness increased with increasing plasticizer content. DSC showed that this unusual result was due to the combined effect of humidity and the high amylose content in starch.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.3
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• pp.249-255
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• 1995

This study was conducted to investigate the effects of some soil conditioners, such as polyacrylamide(PAM), polyvinylalcohol(PVA) and Bitumen emulsion, on aggregate formation and stability, wetting angle, sorptivity and penetrability of the soil with different textures : sand, sandy loam, loam and clay loam. A pot experiment was carried out to find out the effect of treatment on the germination and growth of lettuce with three textures : sand, sandy loam and silt loam. Soil aggregates larger than 2mm in untreated soils at dry condition were naught in sand, 45% in sandy loam, 80% in loam and 90% in clay loam. Treatments of soil conditioners tended to increase the occurrence of soil aggregate larger than 2mm, which were 20~25% in sand, 55~75% sandy loam, but not affected greatly aggragate occurence in loam and clay loam. The aggregate instability was decreased by the soil conditioner treatment. The wetting angles of the soils were greatly changed by hydrophobic of Bitumen, but those were changed slightly by PVA and PAM application. The sorptivity and penetrability data indicated that the effects of different materials on these parameters differed depending upon soil texture. Application of PVA and PAM were no effect exceptive in sand. Application of Bitumen revealed that water movement was not showed in all soils. The germination rate, root weight and top plant weight of lettuce were increased in all soils by PAM treatment as compared to untreated soils. Particularly the greater effect was occurred in sand soil than in sandy loam and silt loam. PAM increased greatly the moisture content and air phase of soils.

• Korean journal of food and cookery science
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• v.19 no.5
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• pp.640-646
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• 2003

The effect of inhibition on N-nitrosodimethylamine (NDMA) formation by methanol extracts from 6 kinds of citrus seed (Citrus sunki, Citrus natsudaidai, Citrus sulcata, Citrus tangerina, Citrus grandis and Citrus obovoidea) were investigated. The contents of moisture, crude protein, crude fat, carbohydrate, ash, flavonoid and total phenol in citrus seeds were 4∼6, 11∼15, 32∼46, 22∼45, 2∼4%, 12∼24mg% and 53∼133mg%, respectively. The solid contents and yield of citrus seed extracts were 0.8∼1.0 and 0.7 ∼ 1.1%, respectively. Nitrite-scavenging activity by methanol extracts from citrus seeds increased with increasing extract dosage. Furthermore, the nitrite scavenging activity was pH dependent being the highest at pH 1.2 (42.7∼96.9%) and the lowest at pH 6.0 (19.9-62.6%). Scavenging effects of nitrite by reaction time showed high effects under 3hr reaction time. The inhibition effect of NDMA formation by the citrus seed was strengthened as the amount of extract increased. The inhibition rate of methanol extracts from citrus seeds on NDMA formation showed 1.2∼39.8%, 21.3∼60.1% and 47.4∼94.0%, according to add 1, 3 and 5$m\ell$, respectively. Therefore, the inhibition effect of NDMA formation by the citrus seed was strengthened as the concentration of extract increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.2
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• pp.139-147
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• 1991

The preservative effect of cellophane film packing on the quality of semi-salted and dried mackerel was studied. The product(P) of semi-salted and dried mackerel was prepared from raw mackerel by filleting, cleaning, soaking in 15%9v/w) salt solution for 30min, draining, packing with cellophane film (PT# 300, thickness:$20{\mu}{\textrm}{m}$) and drying for 4 hrs at $40^{\circ}C$ in hot air dryer. The product (C) was also prepared without cellophane film packing after draining. The product (C) and (P) were stored at $5.0{\pm}0.5^{\circ}C$. After processing and during storage, moisture content of product (P) was higher than that of product (C), but contents of VBN(volatile basic nitrogen), amino nitrogen and TMA of product (P) on dry basis were lower than those of product (C). Viable cell count, TBA value, peroxide value and decreasing rate of polyenoic acid of product (P) were also lower than those of product (C). In sensory evaluation, the shelf life of product (C) was about 9 days and that of product (P) was about 14 days. From the results of chemical and sensory evaluation, it was concluded that cellophane film packing was a good condition for preserving the quality of semi-salted and dried mackerel.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.360-365
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• 2016

This study examined the quality characteristics of bagel added with tomato powder (0, 3, 6, and 9%). Density of dough significantly increased with tomato powder content, whereas pH significantly decreased. Baking loss rate significantly decreased with tomato powder content while moisture significantly increased. Lightness of bagel significantly decreased with increasing tomato powder content, whereas redness and yellowness significantly increased with tomato powder content. Hardness was lower in the addition group than in the control group; springiness, cohesiveness, gumminess, and chewiness significantly decreased with increasing tomato powder content. 2,2-Diphenyl-1-picrylhydrazyl radical scavenging activities and total phenol contents significantly increased as tomato powder content increased. For quality assessment, the 3% addition group received the highest ratings in terms of appearance, color, taste, and overall quality but not texture, indicating the highest potentials for development.

• Journal of agriculture & life science
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• v.43 no.2
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• pp.9-15
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• 2009

The objectives of this study was to obtain the basic information for reasonable management of soil ecosystem damaged by pine wilt disease. Soil temperature and moisture content were $15.3{^{\circ}C}$ and 11.5% at whole-cut site, $14.4{^{\circ}C}$ and 13.5% at partial-cut site, and $13.7{^{\circ}C}$ and 14.8% at control site, respectively. The content of soil organic matter throughout the study period ranged from 2.11 to 2.64% at whole-cut site, 2.26 to 3.33% at partial-cut site, and 2.27 to 3.10% at control. Soil respiration rates showed seasonal fluctuations increasing in summer, which showed positive correlations between soil respiration and soil temperature. Average soil respiration were 0.24, 0.36 and $0.32gCO_{2}/m^{2}/hr$ at whole-cut site, partial-cut site, and control, respectively. $Q_{10}$ values ranged from 2.39 to 2.68 at Pinus densiflora stands damaged by pine wilt disease. Annual soil respiration rate at whole-cut site, partial-cut site and control were 8.1, 15.6 and $14.6tCO_{2}/ha/yr$, respectively.

• FLOWER RESEARCH JOURNAL
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• v.16 no.3
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• pp.211-217
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• 2008

To build up data for mutation breeding of lily, sensitivity to irradiation of bulb, seed and pollen was investigated. The bulbs of seven cultivars including 'New Wave' were very sensitive to gamma rays. Non-irradiated bulbs produced plants with bloom as normal. However, irradiated bulbs showed retarded growth and did not flower. Bulbs of 'New Wave' and 'Tiny Dino' irradiated with 125Gy gamma rays survived, but their growth rate dropped considerably. Part or whole leaves of the other cultivars except 'New Wave' and 'Tiny Dino' withered. Moisture content of individual scale was 72~78% depending on cultivar. Bulblet formation from untreated scales was 100%. Among all irradiated scales only 'Siberia' scales showed 8.5% bulblet formation when irradiated with 50Gy gamma rays. Pollen germination as affected by gamma ray irradiation had no consistent tendency. When dosage of $F_1$ 'Augusta' seeds reached 300Gy, their survival ratio was drastically decreased. Bulblet formation in vitro was observed only in non-irradiated seeds. Lethal dose ($LD_{50}$) of seed was less than 100Gy. Height and width of $F_1$ 'Augusta' bulblets in vitro irradiated with gamma rays decreased as dosage increased regardless of the culture method. The percentage shoot formation was 100% in non-irradiated bulblets and 15~60% in irradiated ones.