• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.101-102
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• 2014

Rising oil price and environmental problems are causing automotive industry to increase fuel efficiency. Improved fuel efficiency in gasoline engine was made possible by development of DISI gasoline engine. Since fuel is injected inside cylinder directly, in-cylinder temperature can be reduced than multi-port injection engine and this leads to increased compression ratio. However, engine performance is largely dependent on mixture formation process due to in-cylinder fuel injection. Especially for spray guided and air guided DISI gasoline engine, injection direction is important factor to mixture preparation. It is because interaction between intake flow and spray affect fuel-air mixture. Hence, in this study, mixture formation characteristics were analyzed by varying injection direction using KIVA 3V release2 code. Residual gas was considered for assuming combustion. Therefore, initial condition for in-cylinder temperature was set equal to the end state of exhaust stroke of combustion cycle. Since angle between intake air flow direction and spray direction affects fluid flow and evaporation field, mixture distribution was affected by fuel injection direction dominantly.

• Journal of the Korean Geotechnical Society
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• v.29 no.2
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• pp.57-64
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• 2013

In this paper, in order to solve high water content of water sludge and promote its recycle, sludge mixtures with various mixing ratios were produced. Sludge mixture consisted of water sludge and weathered granite soil. Their physical properties and unsaturated characteristics (soil-water characteristic curve, and unsaturated permeability function) were investigated by laboratory tests. Experimental test results indicated that at a given matric suction volumetric water content of sludge mixture increased as water sludge content increased. Air entry values of sludge mixture increased from 0.9 kPa to 2.4 kPa with an increase in water sludge content or fine content. In addition, unsaturated permeability function, which is an important factor for performing infiltration analysis, was predicted using saturated permeability and soil-water characteristic curve of sludge mixture.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.2
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• pp.113-123
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• 1995

This study was conducted to find out appropriate rates of seed mixture of both native and foreign plants in order for stabilization of early afforestation and proper vegetation on road slope. The results are summarized as follows: 1. Characteristics of germination : After seeding, 2 weeks for both Lespedeza bicolor and Lespedeza cuneata, and 4 weeks for both Arundinella hirta and Zoysia japonica were needed for vigorous germination, and 1-4 wee17s for 3 cool-season grasses were spent for gradual germination. 2. Plant height : There was no difference between Lespedeza cuneata and Lespedeza bicolor in plant height by 7 treatments. As mixture rates of cool-season grasses were lowered, plant height of Arundinella hirta became longer. Descending order of co81-season grasses for plant height was Tall fescue, Perennial ryegrass and Creeping redfescue. 3. Number of tillers : The number of tillers tended to increase in the experimental plots where competition was low. 4 Ground cover rate : Ground cover rate was the highest in Mixture IV (96.7%) and was fluctuated from 13.3% on Sept. 13 to 45% on Nev. 3 in Mixture III. Descending order of gronud cover rates in 7 treaments was Mixture IV, Mixture III. Mixture II, Mixture Ⅶ, Mixture V, Mixture Ⅵ, Mixture I, and Mixtur III when measured on Oct. 13 5. Visual assessment: High preferences were observed on Mixture IV and Ⅶ In sun the best seed mixtures were Mixture IV and Ⅶ. It meant that (1) either mixture of 70% the native plants with 30% cool-season graaes or (2) mixture of 80% the native plants with 20% cool-season glasses was best for this study.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.7
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• pp.41-46
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• 2010

With the improvement of industrial society, high quality electrical energy, simplification of operation and maintenance, and ensuring reliability are being required. Also we request an urgent change from $SF_6$ gas to an environment-friendly gas insulation material. In this paper, the experiments of breakdown characteristics by pressure and gap change of $N_2/O_2$ mixture gas through a GIS (Gas Insulated Switchgear) model were described. This paper reviews basic data of the surface discharge characteristics for Teflon resin in not only pure $N_2$, $N_2:O_2$ mixture gas as being focused on environmentally-friendly insulating gas, but also $SF_6$. Also, insulation characteristics by breakdown voltage and surface discharge voltage of $N_2:O_2$ mixture gas in the experimental chamber were studied.

• Journal of Ocean Engineering and Technology
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• v.28 no.2
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• pp.140-146
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• 2014

This study investigated the engineering characteristics of non-sintering binder-stabilized mixtures consisting of different ratios of a hardening agent(3%, 6%, 9%, 12%) for recycling industrial by-products through several series of laboratory tests. The hardening agents consisted of two kinds of non-sintering binders(NSB-1, NSB-2), which were developed by using inter-chemical reactions among blast furnace slag, phospho-gypsum, and an alkali activator. In addition, ordinary Portland cement(OPC) was used to compare the engineering characteristics of the stabilized mixture. An unconfined compressive test showed that the unconfined compressive strength increased with the curing time and mixing ratio. Experimental test results indicated that the 7-day strength of the NSB-1 mixture was similar to that of the OPC mixture. However, its 28-day strength was higher than that of the OPC mixture. The secant module of elasticity showed a range of $E_{50}=(42-109)q_u$ regardless of the agents. Based on the results of triaxial tests, the cohesion and friction angle increased with the mixing ratio.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.10
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• pp.1311-1317
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• 2001

To investigate only the effects of the stratified mixture distribution on initial flame propagation and combustion characteristics, the instantaneous equivalence ratio in the spark plug gap and combustion pressure were measured simultaneously In a constant volume chamber, To induce the stratified propane-air mixture distribution near the spark plug, counter-flow typed mixture injection system was used under the constant mean equivalence ratio $\Phi$$\_$mean/= 1.0 The instantaneous equivalence ratio was measured by a single-shot Raman scattering with narrow-band KrF excimer laser. The measuring error was within the limit of $\pm$ 3.5% provided that the proposed method was applied to the measured Raman signals. Judging from mass fraction burned derived from the measured pressure, the optimum combustion characteristics were shown under the condition that the local equivalence ratio in the spark plug was near 1.28$\pm$0.04, and these characteristics were more remarkable at the initial stage of combustion.

• Journal of the Society of Disaster Information
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• v.7 no.1
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• pp.32-42
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• 2011

Many researches have been conducted to evaluate the performance of modified asphalt concrete mixtures. The research was conducted to estimate the laboratory mechanical characteristics of Elvaloy-modified asphalt concrete mixture. To achieve its intended objective, indirect tensile test and resilient modulus test were performed. The rest results revealed that indirect tensile strengths and resilient moduli of the Elvaloy-modified asphalt concrete mixture were higher than those of the conventional dense-graded. As a result, within the limits of the tests conducted in this research, it is predicted that the performance and stability of the Elvaloy-modified asphalt concrete mixture are better than that of the conventional dense-graded one.

• Journal of the Korean Society of Costume
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• v.61 no.4
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• pp.38-51
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• 2011

The purpose of this study is to offer data that designers can utilize substantially, by developing creative materials in knit fashion through the analysis relevant to expression characteristics on the mixture in high low class culture, which were shown in knit fashion of contemporary women, as one of methods of pursuing a plan for being able to be appeared creative and unique knit wear. As for a method of this research, studied concept and characteristics on the mixture in high low class culture by preceding researches. And women's knit fashion was selected that is seen to be 3~18 gauge among the world's 4 collections from 2000~2008. The analysis was made with the analytical frame in mixture pattern, and the analytical frame in design element, and item. The results are as follows. The mixture of kidult element and high fashion was shown with characteristic of expressing humor and fun with graffiti, expression like character and cartoon, and fairy-tale fantasy through the exaggerated trifling article. The mixture of grungy element and high fashion was shown with the expression characteristic in the mixture of heterogenous pattern, and in tear, slit without the end treatment due to fraying the end strand in the knit fashion with basic stitch, patch work, fringing and tone-down gray, use of khaki and blue color, and match in opposite color. The mixture of underwear and high fashion was shown the expression characteristic with the emphasis on underwear line like volume up, or with the mixture of details such as pants in diverse lengths, mini skirt, underwear lace, and ribbon.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.5
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• pp.97-104
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• 2007

The object of this work is to analyze the macroscopic spray performance and atomization characteristics between diesel and biodiesel fuels. In this study, the effects of mixture ratios of biodiesel fuel on the spray tip penetration, fuel injection rate, spray cone angle, and the atomization characteristics such as droplet size, droplets distribution, and spray arrival time according to the axial distance were investigated at various injection parameters. It is revealed that the injection rate is more affected by injection pressure than mixture ratio. And, the spray development process is closely matched between diesel and biodiesel fuels. However, the droplet atomization characteristics of biodiesel shows deteriorated results as the mixture ratio of biodiesel increased because of the high viscosity and density.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.6
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• pp.44-50
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• 2002

The spray characteristics of GDI(Gasoline Direct Injection) injector affects on engine efficiency and emission of a GDI engine. Thus, many researchers have investigated the spray characteristics and the mixture formation of GDI injector. In this study, it was tried to provide the fundamental data for GDl injector design which effects on the spray macroscopic characteristics such as penetration and spray angle. In addition, the mixture formation 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. The results show that as injection pressure increases but as ambient pressure increases, spray penetration decreases and spray angle doesn't affected by increasing injection pressure and ambient temperature. 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.