• Korean Journal of Agricultural Science
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• v.48 no.2
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• pp.201-207
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• 2021

This study evaluated the influence of enzyme mixture supplementation on the growth performance, nutrient digestibility, and fecal score of growing pigs. A total of 72 pigs with an initial body weight of 20.23 ± 1.46 kg were randomly assigned to two treatments consisting of a basal diet and the basal diet supplemented with 0.5% enzyme mixture. During a 19-day trial, no significant difference was observed in the body weight (BW) and average daily feed intake (ADFI) of the pigs. However, a gradual increase in the average daily gain (ADG) was observed during the period from day 14 to day 19 and the overall period in pigs fed a diet supplemented with the 0.5% enzyme mixture (p < 0.10) as compared to the pigs that were fed the control diet. From days 4 to 14 and in the overall experiment, a gradual increase in the feed conversion ratio (FCR) (p < 0.10) was observed with the inclusion of 0.5% enzyme mixture supplementation. The nutrient digestibility of dry matter (DM), nitrogen (N), and energy were not affected by enzyme mixture supplementation. In addition, dietary supplementation with the enzyme mixture had no significant effects on the fecal score of growing pigs. In summary, supplementation with the enzyme mixture had beneficial effects on the ADG performance but failed to have a significant effect on growth performance (BW), nutrient digestibility, and fecal score.

• Progress in Superconductivity and Cryogenics
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• v.21 no.2
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• pp.10-14
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• 2019

In order to improve resource value, separation of nonferrous metals obtained from crushed materials of home appliances is required. In this study, we aimed to develop a continuous separation system by magneto-Archimedes method using magnetic fluid as a medium and the permanent magnet as a magnetic field source. Firstly, the separation conditions were examined in which only copper is settled and the difference in levitation positions between aluminum and other metals are over 1 cm. Based on the results, levitation experiment of each metal and separation experiment from the mixture of nonferrous metals were confirmed. The separation experiment showed that the continuous separation of copper and aluminum from a mixture of nonferrous metals is possible.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.4
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• pp.296-301
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• 2005

This study was conducted to get the basic data on an effect of food waste compost for rock cut-slopese vegetation. Two foreign cool-season grasses and native plants were used for this experiment. Cool-season grasses were Festuca ruba and Lolium perene, Native plants were Amorpha fruticosa, and Indigofera pseudo-tinctoria. Amorpha fruticosa, Indigofera psendo-tinctoria, and Lolium perenne decreased in germination rate and plant height at NaCl concentrations of $0.4\%$ or over suddenly. Festuca rubra occurred to the sudden growth hindrance at NaCl concentrations of $0.2\%$ or over. Amorpha fruticosa and Indigofera pseudo-tinctoria appeared for germination of $45\%$ at all experiment plots. Lolium perenne increased in plant height as trial rate of food waste compost was abundant. Ground cover rate was the highest in Mixture III by $89.3\%$ and was fluctuated from $47.0\%$ after 30 days to $64.1\%$ after 45 days in Mixture 1. Descending order of ground cover rates in 4 treatments was Mixture III, Mixture IV, Mixture II, and Mixture I. As the growth

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.4
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• pp.275-282
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• 1996

This experiment was canied out to investigate the effect of pasture types(mixture and mono tall fescue pasture) and endophyte infection on the dry matter yield, forage quality and animal performance of pasture plants at the Experimental Field of Grassland and Forage Crops Division, National Livestock Research Institute, Suweon, in 1994. The results obtained are surmmarized as follows : DM yield of tall fescue monoculture was significantly higher(p<0.05) than that of mixture pasture, while DM yield of endophyte-infected pasture was significantly higher(p<0.05) than that of endophyte-free for two pasture types. Crude protein yield(CPY) of tall fescue monoculture was significantly higher(p<0.05) than that of mixture, and the higher CPY with endophyte-infect tall fescue for both pasture types resulted from higher DM yield of the pastures. NDF and ADF contents of pasture plants were not influenced by pasture types, and there was no difference for NDF and ADF contents between endophyte-infect and -free pasture mixture, however, those of pasture plants were increased with endophyte-infect tall fescue in monoculture. IVDMD of pasture plants was increased with mixture and endophyte-free tall fescue for both pasture types. IVDMD of pasture plants was greatly influenced by pasture types and endophyte infection. There were no significant differences in average daily gain of Korean native cattle between pasture types, but those of the cattle were significantly increased with endophyte-free tall fescue for both pasture types(p<0.05). Based on the results of this experiment, it is suggested that a slightly more forage yield could be obtained , from monoculture and endophyte-infected tall fescue. However, liveweight gain was increased by mixture and endophyte-free tall fescue with good quality.

• The Journal of Korean Medicine
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• v.20 no.2
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• pp.141-145
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• 1999

The aim of this experiment was to investigate the effects of a mixture of Scutellariae Radix, Coptidis Rhizoma and Coptidis Rhizoma water extracts on the blood pressure, plasma renin activity, plasma levels of aldosterone and atrial natriuretic peptide (ANP) in spontaneously hypertensive rats (SHR). The results of this study were as follows: 1. Systolic blood pressure decreased significantly after the administration of a mixture of Scutellariae Radix, Coptidis Rhizoma, and Coptidis Rhizoma water extract 0.2 ml/200g. 2. Plasma renin activity and plasma levels of ANP were not changed after the administration of a mixture of Scutellariae Radix, Coptidis Rhizoma and Coptidis Rhizoma water extracts, 3. Plasma levels of aldosterone was increased significantly after the administration of a mixture of Scutellariae Radix, Coptidis Rhizoma and Coptidis Rhizoma water extracts 0.1 ml/200g.

• Journal of the Korean Society of Safety
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• v.28 no.1
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• pp.29-34
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• 2013

When flammable gases are mixed with air or oxygen in the explosion concentration range and are ignited by sufficiently large electrostatic discharge energy, they may explode causing severe disaster in workplace. The minimum ignition energy(MIE) of single gas-air mixtures has been already investigated by many research, but the MIE of mixtures of more than ternary gas mixture is not examined yet. The purpose of this study is to investigate the MIE of a ternary gas(methane, ethylene, hydrogen, propane) mixtures experimentally. The results of our experiment show that the ignition of a methane-ethylene-air, methane-hydrogen-air, methane-propane-air, ethylene-hydrogen-air, ethylene-propane-air and hydrogen-propane-air mixture due to electrostatic discharge energy primarily depends on that the mixture: the MIE decreases gradually with the increase of having the lower MIE than other mixture ratio in the normal atmospheric pressure.

• International Journal of Automotive Technology
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• v.6 no.2
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• pp.79-85
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• 2005

This work is to investigate the surface heat flux and combustion characteristics of premixed propane mixture in a constant volume chamber. The experiment of heat flux and combustion characteristics of premixed propane mixture are performed with various equivalence ratio and initial pressure conditions. Based on the experimental results, it is found that the maximum instantaneous temperature is increased with the increase of initial pressure in the chamber. There are significant differences in the burning velocity of premixed propane mixture at different measuring points in the constant volume combustion chamber. A]so, the trends of temperature difference at each measuring points are similar to the burning velocity in the combustion chamber. It is concluded that the total heat loss during the combustion period is affected by the equivalence ratio and the initial condition of fuel-air mixture.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1541-1546
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• 2015

The objective of this research was to evaluate the toxicity of the industial xenobiotic Aroclor 1248 (A) and natural origin substances~elemental sulfur (S80) and oleic acid (OA) and their binary mixtures to V. fischeri bioluminescence during the prolonged exposure time (up to 60 min). The bioluminescence quenching test was used to determine the toxic effects. Full factorial experiment design and multiple regression analysis and the comparison of binary mixture effect with the sum of effects of individual chemicals were used for the evaluation of combined effects of toxicants. The analysis of general trend of mixture toxicity to bioluminescence showed that mixture toxic effects were reversible up to 60 min. Data analysis revealed different joint effects, which were depended on mixture composition. S80 enhanced toxic effect of A and acted additively with synergistic interaction. Hydrophobic OA in mixture with A acted antagonistically and in mixture with sulfur caused an additive effect with antagonistic component of interaction. It was concluded that low concentrations of natural toxic substances present in environmental samples as mixtures of chemicals can define the toxicodynamic character of industrial xenobiotics.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.1
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• pp.69-75
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• 2003

In this study, his technique was applied to a GDI spray in order to investigate the mixture distribution. In addition, the homogeneity degree and diffusion effect according to ambient temperature in the high pressure chamber were analyzed by using an entropy analysis method. From this experiment, we could find that entropy analysis is very effective method for the analysis of mixture formation, and the entropy values increase with the progress of uniformity in diffusion Process. we tried to provide the fundamental data for parameter which effects on the spray macroscopic characteristics with mixture ratio of diesel and gasoline. In addition, the mixture formation was analyzed by using entropy analysis. The entropy analysis is based on the concept of statistical entropy, and it identifies the degree of homogeneity in the fuel concentration. From the entropy analysis results we could find that the direct diffusion phenomena is a dominant factor in the formation of a homogeneous mixture at downstream of GDI spray especially in vaporizing conditions. As to increasing ambient temperature and increasing gasoline rate, the entropy intensity using the statistic thermodynamics method is increased because evaporation rate is higher gasoline than diesel.

• Journal of Korean Elementary Science Education
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• v.34 no.4
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• pp.419-433
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• 2015

Analogical reasoning is a central component of human cognition and contributes to scientific discovery and to develop science education. In this study, we investigated the process features of lower elementary school students' analogical reasoning to explain mixture concept. The subjects are 24 lower elementary students. And the research design includes three phases instruction to investigate the features of students' self generated analogy. Phase 1 is the introduction of analogy in which student learn to use analogy. Phase 2 is a POE class about mixture conception. Piaget and Inhelder studied the conception of mixing among children in relation to cognitive development. In phase 2, we taught the student with Piaget and Inhelder's the experiment and observed the features of learning process about mixture conception. Phase 3 is students' generation of analogy (self generated analogy) for the experienced phenomena in phase 2. We analyzed the students' responses through the three phases in the view of Gentner's Structure Mapping Theory. The results showed that many lower elementary school students even before formal operation stage understood the mixture conception and made well their self generated analogy to explain the mixture conception in spite of the difficulty of making self generated analogy.