• Geomechanics and Engineering
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• v.15 no.2
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• pp.783-791
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• 2018

In consideration of the mesoscopic structure of soil-rock mixtures in which the rock aggregates are wrapped by soil at normal temperatures, a two-layer embedded model of single-inclusion composite material was built to calculate the shear modulus of soil-rock mixtures. At a freezing temperature, an interface ice interlayer was placed between the soil and rock interface in the mesoscopic structure of the soil-rock mixtures. Considering that, a three-layer embedded model of double-inclusion composite materials and a multi-step multiphase micromechanics model were then built to calculate the shear modulus of the frozen soil-rock mixtures. Given the effect of pore structure of soil-rock mixtures at normal temperatures, its shear modulus was also calculated by using of the three-layer embedded model. Experimental comparison showed that compared with the two-layer embedded model, the effect predicted by the three-layer embedded model of the soil-rock mixtures was better. The shear modulus of the soil-rock mixtures gradually increased with the increase in rock regardless of temperature, and the increment rate of the shear modulus increased rapidly particularly when the rock content ranged from 50% to 70%. The shear modulus of the frozen soil-rock mixtures was nearly 3.7 times higher than that of the soil-rock mixtures at a normal temperature.

• International Journal of Air-Conditioning and Refrigeration
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• v.16 no.4
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• pp.117-123
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• 2008

The present study is directed at flow and heat transfer of $CO_2$ and oil mixtures in a circular tube. PAG and POE oils are considered in this study. Flow characteristics of $CO_2$ and oil mixtures have been investigated by flow visualization. Pressure drop has been measured in the range of operating mass flow rate from 0.1 to 0.4 kg/min in a circular tube. Heat transfer characteristics of $CO_2$/oil mixtures have been investigated using a counterflow heat exchanger. In case of pure liquid $CO_2$ as well as $CO_2$ and POE mixtures, flow are seen to be uniform so that $CO_2$ and POE oil are still miscible even at flowing state. However, it is found that $CO_2$ and PAG are not miscible. Pressure drop of $CO_2$/PAG mixtures are much higher than that of $CO_2$/POE mixtures as well as pure $CO_2$ at a fixed mass flow rate. As the concentration of POE oil is increased from 0 to 5 wt%, pressure drop is increased. However, heat transfer rate and heat transfer coefficient of $CO_2$/POE mixtures are much higher than that of $CO_2$/PAG mixtures. The f-factor correlation and Nusselt number correlation for $CO_2$/POE oil mixtures are suggested in this paper.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.1075-1080
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• 2005

The objective of this experiment was conducted to evaluate the effect of various legumes in mixtures: AA mixtures(orchardgrass 40%+tall fescue 25%+Kentucky bluegrass 15%+alfalfa 20%), RC mixtures (orchardgrass 40% + tall fescue 25% + Kentucky bluegrass 15% + red clover 20%) and WC mixtures (orchardgrass 50% + tall fescue 25% + Kentucky bluegrass 15% + white clover 10%). The field trials were conducted from 2000 to 2003 at Chungnam National University in order to evaluate the dry matter yield and forage quality on different legumes in mixtures. The dry matter yield was significantly higher in WC mixtures than in other mixtures(p<0.05). In the chemical composition, the content of crude protein and dry matter digestibility were higher in WC mixtures than in other mixtures. However, the content of fibrous constituents of WC mixtures was lower than in other mixtures. The yields of crude protein dry matter and digestible dry matter were significantly higher in WC mixtures than in other mixtures. In botanical composition of alfalfa, red clover and white clover in each mixture were maintained 21%, 36% and 48% respectively, at the last cutting time in 2003. The results of this experiment indicated that WC mixtures were more effective in enhancing the DM yield and forage quality, but it needs to control the optimum botanical composition of WC.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.701-706
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• 2004

The objective of this experiment was to compare the dry matter intake, nutrients digestibility and nitrogen and energy utilization of herbages harvested from turf type mixtures {tall fescue(Rebell Jr.) 40%+ perennial ryegrass(Palmer II) 20%+ Kentucky bluegrass(Newport) 10%+ redtop(Banicuda) 10%+ red fescue(Salem) 10%+ creeping bentgrass(Crenshaw) 10%} and tall type mixtures {orchardgrass(Potomac) 40%+ tall fescue(Fawn) 20%+ Festuloium braunii(Paulita) 10%+ perennial ryegrass(Reveille) 10%+ timothy(Climax) 10%+ red clover(Kenblue) 10%+ alfalfa(Vernal) 10%} by Korean native goats. This experiment was conducted by total collection method in laboratory, 2001. The voluntary DM intake per body weight were slightly higher for turf type mixtures(28.9g) than that of tall type mixtures(26.2g), but there was no significant difference. The digestibility of cellular constituents was slightly higher for turf type mixtures than that of tall type mixtures(p<0.05), but digestibility of DM, NDF and ADF did not differ between two mixtures. The retained nitrogen percent(apparently biological value) was slightly higher for turf type mixtures(56.7%) than that of tall type mixtures(56.4%), but there was no significant difference between two mixtures. Apparently retained digestible energy was slightly higher for turf type mixtures(58.3%) than that of tall type mixtures(57.9%), but there was no significant difference between two mixtures. Based on the results, the herbage utilization by Korean native goats did not showed any significant difference between two mixtures, therefore there is a possibility that herbages of turf type mixtures can be used as a roughages by livestock.

• The Journal of Korean Medicine
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• v.26 no.4
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• pp.62-73
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• 2005

Objectives: This study was designed to identify the ergogenic effects of Red ginseng and Paeonia radix mixtures and optimal ratios. Materials and Methods: This study was conducted by administering treatments of Red ginseng and Paeonia radix mixtures to rats and by measuring the time to exhaustion by treadmill running. Results: The treatment of Red ginseng and Paeonia radix mixtures to the rats increased the time to exhaustion by treadmill running. The most potent inhibition of Red ginseng and Paeonia radix mixtures on the 5-HT synthesis and the TPH expression in the dorsal raphe was observed at the dose of 200 mg/kg and the optimal ratio of Red ginseng and Paeonia radix for the maximum efficacy was 50:50. Under normal conditions (not exercise), long-term treatment of Red ginseng and Paeonia radix mixtures did not affect the 5-HT synthesis and the TPH expression in the dorsal raphe, suggesting that Red ginseng and Paeonia radix mixtures does not alter serotonin level in the normal rats. The suppressive effect of Red ginseng and Paeonia radix mixtures on the 5-HT synthesis and the TPH expression during exercise is a possible ergogenic mechanism of these mixtures. Conclusions : Red ginseng and Paeonia radix mixtures reduce exercise-induced fatigue, and have the effect of acting as ergogenic aids on the time to exhaustion by treadmill exercise and on 5-HT synthesis and TPH expression.

• 전기의세계
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• v.28 no.4
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• pp.39-46
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• 1979

The effective ionization coefficient in $SF_{6}$/$N_{2}$ mixtures was attempted to derive from the pure gases. Measurements of static breakdown voltage were made under the uniform field at pressures up to 4 bar in order to compare with the results obtained from this assumption. The relative performance of $SF_{6}$/$N_{2}$ mixtures to pure $SF_{6}$ was also investigated. The effect of surface roughness on discharge thresholds in $SF_{6}$/$N_{2}$ mixtures was calculated employing the simplified model and mesurements of breakdown voltages for a gap with an artificial protrustion were also made. The experimental results show that the effective ionization coefficient in gas mixtures can not be reliably estimated from the values measured for the pure gases. Therefore, basic parameters for $SF_{6}$/$N_{2}$ mixtures must be measured by investigation of the mixtures themselves. The relative performance of mixtures to pure $SF_{6}$ could be considered with the values of pR.

• Bulletin of the Korean Chemical Society
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• v.18 no.8
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• pp.841-850
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• 1997

A simple molecular theory of mixtures is formulated based on the nonrandom two-fluid lattice-hole theory of fluids. The model is applicable to mixtures over a density range from zero to liquid density. Pure fluids can be completely characterized with only two molecular parameters and an additional binary interaction energy is required for a binary mixture. The thermodynamic properties of ternary and higher order mixtures are completely defined in terms of the pure fluid parameters and the binary interaction energies. The Quantitative prediction of vapor-liquid, and solid-vapor equilibria of various mixtures are demonstrated. The model is useful, in particular, for mixtures whose molecules differ greatly in size. For real mixtures, satisfactory agreements are resulted from experiment. Also, the equation of state (EOS) is characterized well, even the liquid-liquid equilibria behaviors of organic mixtures and polymer solutions with a temperature-dependent binary interaction energy parameter.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.3
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• pp.185-190
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• 2005

The objective of this experiment was to compare the dry matter intake, nutrients digestibility and nitrogen and energy utilization of herbages from mixtures types; conventional mixtures(orchardgrass 50+ tall fescue 20+perennial ryegrass 10+Kentucky bluegrass 10+white clover $10\%$), complex mixtures (orchardgrass 40+ tall fescue 20+perennial ryegrass 10+Kentucky bluegrass 10+redtop 10+alfalfa 5+red clover $5\%$) and simple mixtures(orchardgrass 80+red clover $20\%$) by Korean native goats. This experiment was conducted by total collection method in laboratory, 2000. The voluntary DM intake per body weight was slightly higher f3r complex mixtures (30.2g) than those of other mixtures. but there was no significant difference. The digestibility of dry matter and cellular constituents were slightly higher for complex mixtures than those of other mixtures (p<0.05), but NDF and ADF digestibilities did not differ among mixtures. The retained nitrogen percent (apparently biological value) was slightly higher fer complex mixtures $(55.1\%)$ than those of other mixtures, but there was no significant difference among mixtures. Apparently retained digestible energy was slightly higher for complex mixtures $(60.2\%)$ than those of other mixtures (p<0.05). Based on the results, the nitrogen and energy utilization of herbage by Korean native goats were slightly higher for complex mixtures than those of other mixtures.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.1081-1086
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• 2005

This study was conducted to investigate the effect of mixture types which consist of different species on the dry matter(DM) yield, botanical composition and forage quality. The experimental design includes three mixture types: Conventional mixtures(orchardgrass 50% + tall fescue 20% + perennial ryegrass 10% + Kentucky bluegrass 10% + white clover 10%), complex mixtures(orchardgrass 40% + tall fescue 20% + perennial ryegrass 10% + Kentucky bluegrass 10% + redtop 10% + alfalfa 5% + red clover 5%) and simple mixtures(orchardgrass 80% + red clover 20%). The DM yield was higher in conventional mixtures(13,070kg/ha) than in other mixtures(p<0.05). In the chemical composition and dry matter digestibility, there was significant difference among mixtures. Crude protein content and dry matter digestibility were higher in complex mixtures than in other mixtures(p<0.05). But, the content of fibrous constituents was higher in conventional mixtures than in other mixtures. The yield of crude protein dry matter(CPDM) and digestible dry matter(DDM) were higher in complex mixtures than in other mixtures. In this experiment, DM yields and quality of mixture types were observed significant difference. therefore, the complex mixtures which combined various species were more effective in enhancing the dry matter digestibility(DMD) and digestible dry matter(DDM) yield.

• Textile Coloration and Finishing
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• v.6 no.4
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• pp.17-26
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• 1994

Poly(ethylene terephthalate)(PET) filaments were treated in binary mixtures of organic solvents such as benzyl alcohol/perchloroethylene(BA/PER), benzyl alcohol/trichloroethylene(BA/TRI), benzyl alcohol/ethylene chloride(BA/EC), methanol/perchloroethylene (ME/PER), and methanol/trichloroethylene(ME/TRI). From the equilibrium swelling of PET, total and partial isotherms of PET for sorption of solvent mixtures and isotherms for distribution of the components between the phases were taken. Also the shrinkage and the crystallinity of PET treated with binary mixtures were investigated. The results obtained were summerized as follows: 1. All isotherms for distribution of the components between the phase deviated from the diagonal in system of PET-binary mixtures. Especially in the binary mixtures of ME/PER or ME/TRI, selectivo sorption of chlorinated hydrocarbon PER and TRI by PET occured. 2. The shrinkage of PET treated in binary mixrures was increased to compare with single solvent-treated, but the composition of binary mixtures corresponding to maximum values of shrinkage was not always agreed with the composition of binary mixtures corresponding to maximum values of shrinkage was not always agreed with the composition of binary mixtures exhibiting of the maximum swelling of PET. 3. The crystallinity of PET treated in binary mixtures generally increased than that of single solvent-treated.