• Journal of Animal Environmental Science
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• v.15 no.2
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• pp.91-98
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• 2009

Object of this study were to determine the influence of collection times of rumen fluid on in vitro dry matter digestibility (IVDMD) of forage crops. The donor cow was fed concentrate once a day and given free access to grass-legume mixture hay. Main plot was consisted of different collection time of rumen fluid; T1: 1 hour before concentrate feeding, T2: 1 hour after feeding, T3: 4 hour after feeding and T4: 8 hour after feeding. A total of 7 samples of 4 different forage crops (barely, Italian ryegrass, crimson clover, rye) were used for the estimation of IVDMD and tested in three replicates. For the $DAISY^{II}$ incubation, each sample was inserted into each filter bag then heat-sealed and incubated in a digestion vessel for 48 h at $39^{\circ}C$. The times of rumen fluid collection had no significant effect on the IVDMD values over all varieties except for 2 breeds of IRG (Kogreen and Kospeed). IVDMD values with T1 over all varieties were slightly higher than other treatments, however those with both T1 of Kogreen and Kospeed varieties were significantly higher than T2 (p<.05).

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.1028-1033
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• 2004

This study was conducted to improve the quality properties of cream soup in accordance with the added amount of sweet pumpkin and Chungdong pumpkin, roux and chicken stock. As the amount of pumpkin was increased, red (a-value) and yellow (b-value) colors increased but its lightness (L-value) remarkably decreased. Also, there was a significant differences in viscosity, color, appearance and overall preference of sensory evaluation. In pumpkin 150 g (37.5%) added, the degree of total preference was high. As the added amount of roux was increased, red and yellow colors decreased by small margin and there was a significant differences in color, flavor, appearance and overall preference of sensory test. At adding roux of 5 mL (1.5%) showed the highest preference. With the adding chicken stock increase the lightness, red and yellow color decreased. It was found by sensory evaluation that there were significant differences in viscosity, color, flavor, appearance and overall preference. At adding chicken stock 150 mL (37.5%) and milk of 50 mL (12.5%) showed the high score in flavor, appearance and total preference.

• Food Science and Preservation
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• v.19 no.4
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• pp.510-518
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• 2012

In this research, to modernize traditional food and to make functional bokryung-byung, bokryung-byungwas made with Poriacocos Wolf powder added. During its storage, its moisture content ranged from 42.89 to 44.85%. The control group had the highes tmoisture content (44.85%), and it was reduced significantly as the Poriacocos Wolf powder in creased. The longer the storage period was, the lower the pH and the higher the acidity was. The total bacterial count increased from 2.70 to 3.00 Log CFU/g right after the manufacture and increased rapidly on the fourth day of the storage with more than 7.00 Log CFU/g. There was no difference between the control group and the bokryung-byung, though. The Hunter's color value after the manufacture, with the increase in the added Poriacocos Wolf powder, showed a significantly reduced brightness, but significantly increased redness and yellowness. Their chromaticity did not change, how ever, during their storageat a temperature of $20^{\circ}C$. The hardness, solidity, gumminess, and cohesiveness of the bokryung-byung increased, unlike in the control group, and its brittleness increased. In terms of the overall preference, the preference for the control group was high, but was higher when 5 % Poria cocos Wolf powder was added during the manufacture of the bokryung-byung. As a result of these correlations, it is believed that elastic and chewy dduks are preferred and bokryung-byungs could be developed as functional dduks.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.1
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• pp.17-25
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• 2001

High salt content in food waste limit use as the potential source of compost. Since sodium chloride content should be lower than one percent to meet requirement for agricultural use of compost, we attempted use of three kinds of co-composting material for food wastes compost, which were fermented, dried, and fresh types of amendments which included pig manure, sawdust and puffed rice hull. Food wastes were composted well and stabilized after around the 40th days of composting. Little difference were found between composts amended sawdust and puffed rice hull. The result indicated that puffed rice hull could be used as a good alternative of sawdust. Because sawdust or puffed rice hull were mixed as amendments to control water contents and to dilute high NaCl content of compost material, the C/N ratios of the final products were significantly high over 40. However, NaCl contents of final products were dropped to less than percent on the fresh weight basis by mixing food wastes and the above amendments with the optimum rates.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.2
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• pp.1-9
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• 2019

GGBFS(Ground Granulated Blast Furnace Slag), one of the representative concrete mineral admixtures, improves the long-term durability and engineering performance of concrete by latent hydraulic activity. In this study, considering 3 levels of W/B(0.37, 0.42, 0.47) and GGBFS replacement ratio(0 %, 30 %, 50 %), durability performances for chloride attack are evaluated, and equations which predict behavior of accelerated chloride diffusion are proposed. Also, the relationship between accelerated chloride diffusion coefficient and passed charge is evaluated. In target curing day, accelerated chloride diffusion tests(Tang's method, ASTM C 1202) and compressive strength(KS F 2405) are performed. In the 730 day's results of accelerated chloride diffusion coefficient, GGBFS concrete has up to 28 % of decreasing ratio compared to OPC concrete, and in those of passed charge, GGBFS concrete has up to 29 % of decreasing ratio compared to OPC concrete. Also, it is deemed that the impact of variation of W/B is less in GGBFS concrete than in OPC concrete. The equations which predict accelerated chloride diffusion coefficient and passed charge are drawn, based on the characteristics of mixture and test results. The equation which predicts passed charge shows slightly higher coefficient of determination than that which predicts accelerated chloride diffusion coefficient.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.2
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• pp.37-43
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• 2019

This study investigated electrical conductivity, electromagnetic shielding effectiveness, and mechanical property to improve electromagnetic shielding performance of high performance fiber reinforced cementitious composites (HPFRCC). Steel fiber, steel slag and carbon black as a conductive material were incorporated into the HPFRCC mixes. In addition, 2% CNT solution which was produced by dispersing multi-wall carbon nanotube (MWCNT) into water was used as a conductive material. In the test results, electrical conductivity of HPFRCC specimens was very low except for the specimen incorporating 1% carbon black. Micro structure of cement matrix was changed as the curing time increased, which negatively affected the conductive network of HPFRCC. In case of HC1 specimen showing a conductive network (0.083 S/cm), the electrical conductivity of the specimen after being dried at $60^{\circ}C$ for 72 hours to exclude the effect of water on electrical conductivity was significantly reduced to 0.0003 S/cm. The most important parameter of electromagnetic shielding effect was found to be a steel fiber while the effect of carbon black and steel slag was very few. The correlation between electrical conductivity and electromagnetic shielding effect does not seem to be clear.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.3
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• pp.150-159
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• 2019

The bond analysis model equation was proposed through the regression analysis of the experimental values of bond behavior for each rebar. In order to verify the appropriateness of the bond analysis model equation, the bond behaviors calculated by the proposed bond analysis model, BPE model and CMR model were compared with experimental values. The proposed bond model showed the closest behavior to the experimental values when compared to other analysis models. The former models can not consider the different properties of GFRP rebar according to composed materials, mixing and manufacturing method and the latter has limitation to express the relationships between bond behavior because of derived formula by numerical analysis. This study proposed the analytical model different considering bond mechanism according to surface type. In order to verity the appropriateness of the bond analytical model, the bond behaviors calculated by the proposed bond analytical model, BPE model and CMR model were compared with experimental values. The proposed bond model showed the closest behavior to the experimental values when compared to other analysis models.

• Resources Recycling
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• v.28 no.4
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• pp.44-50
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• 2019

In the electric arc furnace process, the chemical energy such as the heat of oxidation reaction and the heat of carbon combustion etc. is consumed as 30% of the total input energy. In order to reduce $CO_2$ emission in EAF, it is necessary to decrease the use of electric power energy during scrap melting stage and increase the use of chemical energy. In general, when the carbon materials is individually charged into the molten steel, the carbon materials floated to the slag layer due to low density before it is dissolved in molten steel. When the concentration of carbon in the molten steel is high, the combustion energy of carbon by oxygen injection can lower the electric power energy and improve the chemical energy consumption. Therefore, an efficient charging methods of carbon material is required to increase the efficiency of carbon combustion heat. On the other hand, Al-dross, which is known as a by-product after Al smelting, includes over 25 mass% of metallic Al, and the oxidation heats of Al is lager than that of carbon. However, the recycling ratio fo Al-dross was very low and is almost landfilled. In order to effectively utilize the heats of oxidation of Al in Al-dross, it is necessary to study the application of Al-dross in the steel process. In this study, the dissolution efficiency of carbon and aluminum in molten steel was investigated by varying the reaction temperature and the mixing ratios of coke and Al-dross.

• The Journal of Engineering Geology
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• v.30 no.4
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• pp.541-555
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• 2020

The grouting method is used for reinforcing and waterproofing the soft ground, increasing the bearing capacity of structures damaged by lowering or subsidence due to rise and vibration, and for ordering. This study attempted to develop a blast furnace slag-based cementless grout material to increase the strength and hardening time of the grout material using reinforcing fibers. In this regard, in this study, it was used in combination with calcium hydroxide, which is an alkali stimulant of the three fine powders of blast furnace slag, and the content of calcium hydroxide was used by substituting 10, 20, and 30% of the fine powder of blast furnace slag. In addition, in order to compare the strength according to the presence or absence of reinforcing fibers, an experiment was performed by adding 0.5% of each fiber. As the content of carbon fibers and aramid fibers increased, the uniaxial compressive strength increased, and it was confirmed that the crosslinking action of the fibers in the grout material increased the uniaxial compressive strength. In addition, it was confirmed that the gel time sharply decreased as the content of the alkali stimulate increased.

• Journal of the Korea Institute of Building Construction
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• v.21 no.1
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• pp.1-10
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• 2021

The purpose of this study is to evaluate the improvement of flow, compressive and flexural strengths of polymer cement mortar(PCM) using SBR latex mixed with blast-furnace slag and fly ash. The test specimens were prepared with SBR polymer dispersion, two types of admixture (blast-furnace slag and fly ash), five polymer-cement ratios (P/C; 0, 5, 10, 15 and 20%), and six admixture contents (0, 3, 5, 10, 15 and 20%), plain cement mortar was also made for comparison. From the test results, the flow of PCM was significantly improved compared to ordinary cement mortar, but the flow was slightly reduced when mixed with blast-furnace slag, and the flow was similar to PCM when mixed with fly ash. In addition, the compressive strength of PCM mixed with admixtures was significantly improved, but the flexural strength did not improve except for some mortars. It can be stated that the optimum mix proportions of PCM using SBR with admixture contents 10 to 15% and P/C 10% for the compressive strength improvement, and P/C 20% for flexural strength improvement are recommended respectively in this study.