• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
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• pp.133-137
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• 2004

The present study is focused on the small scale turbulent mixing processes in the scalar field. In order to deal with molecular mixing in turbulent flow, the linear eddy model is addressed. In each realization, the molecular mixing term is implemented deterministically, and turbulent stirring is represented by a sequence of instantaneous, statistically independent rearrangement event called by triplet map. The LEM approach is applied with relatively simple conditions. The characteristics of scalar mixing and PDF profiles are addressed in detail.

• Archives of Pharmacal Research
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• 제5권2호
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• pp.53-60
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• 1982

The mixing of salicylic acid and wheat starch powders was studied using a V-type mixer. After the optimum operating conditions of the mixer were examined, the mixing characteristics relating to dilution ratio, particle size of active ingradient and addition ratio of lubricants were investigated. The coefficient of variation was expressed by a power law relating to the dilution ratio and the particle size of active ingredient. Furthermore, the comparison of results with the theoretically estimated value of mixing index suggested that the mixing of cohesive pharmacceutical powders is a complex stochastic process and cannot be explained fully by a simple theory based on a complete random mixing.

• 한국환경농학회지
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• 제15권3호
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• pp.355-361
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• 1996

The Purpose of this study was to investigate the effect of the Change in the operating conditions on rotary turning compost plants. The major parameters investigated were moisture content and mixing of the sawdust and pig farm wastewater. Pig farm scale composting plants with mixing rotary were used in this study. Wastes used for the study were sawdust, pig manure, urine and wastewater. When the moisture content was 75%, the compost product obtained from the plants had better physical characteristics than that obtained from the plants with moisture contents of 70%, 80% and 85%.(two a day mixing). When the turning was twice a day, the compost product obtained from the plants had better characteristics than that obtained from non-mixing.(moisture content 75%). C/N ratio, pH value and coliform bacterial population were stable in the compost.

• Nuclear Engineering and Technology
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• 제55권10호
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• pp.3775-3786
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• 2023

Mixing Vane Grid (MVG) is one of the most important structures in fuel assembly due to its high performance in mixing the coolant and ultimately increasing Critical Heat Flux (CHF), which avoids the temperature rising suddenly of fuel rods. To evaluate the mixing performance of the MVG, a Total Diffusion Coefficient (TDC) mixing coefficient is defined in the subchannel analysis code. Conventionally, the TDC of the spacer grid is obtained from the combination of experiments and subchannel analysis. However, the processing of obtaining and determine a reasonable TDC is much challenging, it is affected by boundary conditions and MVG geometries. In is difficult to perform all the large and costing rod bundle tests. In this paper, the CFD method was applied in TDC analysis. A typical 5 × 5 MVG was simulated and validated to estimate the mixing performance of the MVG. The subchannel code was used to calculate the TDC. Firstly, the CFD method was validated from the aspect of pressure drop and lateral temperature distribution in the subchannels. Then the effect of boundary conditions including the inlet temperature, inlet velocities, heat flux ratio between hot and cold rods and the arrangement of hot and cold rods on MVG mixing and TDC were studied. The geometric effects on mixing are also carried out in this paper. The effect of vane pattern on mixing was investigated to determine which one is the best to represent the grid's mixing performance.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.285-288
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• 2014

Experiments have been performed for the burners used in the non-oxidizing direct fired furnaces for the cold rolled plate to investigate the effect of fuel/air mixing patterns of the burner nozzle on flame shape, temperature and combustion gas concentration. CFD simulation has also been performed to investigate the mixing state of air-fuel for a nozzle mixing burner and a partially pre-mixing burner. A partially pre-mixing burner showed that flame temperature increased up to $26^{\circ}C$ on average compared than that of the nozzle mixing. It also showed that the mixing distance is important at the partially pre-mixing burner. Test results for a partially pre-mixing burner showed that the residual oxygen concentration and the volume ratio of $CO/CO_2$ of the flame were applicable to be used in field furnaces.

• 한국건축시공학회지
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• 제1권2호
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• pp.174-178
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• 2001

This study was performed to control the thermal crack of the mat footing slab in the multi-purposed buildings. In this study, we executed the mixing design of concrete to satisfy the workability and the quality according to the site conditions. And, we evaluated quantitatively about the possibility of thermal crack by using hydration heat analysis system. Finally, we proposed the optimal mixing conditions, curing methods and curing period which all factors are considered. As a result, the optimal mixing conditions were : W/B 41%, unit binder 375kgf/$\textrm{m}^3$, FA replacement ratio 20%. Lowest thermal stress was 22.0kgf/$\textrm{cm}^2$ and at that time thermal crack index was over 1.5, when the coefficient of thermal conductivity was lowest among the curing conditions. And, the total curing time was estimated at 6.7 days according to curing steps.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.533-538
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• 2001

This study was peformed to control the thermal crack of the mat footing slab in the multi-purposed buildings. In this study, we executed the mixing design of concrete to satisfy the workability and the quality according to the site conditions. And, we evaluated quantitatively about the possibility of thermal crack by using hydration heat analysis system. Finally, we proposed the optimal mixing conditions, curing methods and curing period which all factors are considered. As a results, the optimal mixing conditions were : W/B 41%, unit binder 375kg/$cm^{2}$, FA replacement ratio 20%. Lowest thermal stress was 22.0kgf/$cm^{2}$ and at that time thermal crack index was over 1.5, when the coefficient of thermal conductivity was lowest among the curing conditions. And, the total curing time was estimated at 6.7 days according to curing steps.

• Journal of the Korean Statistical Society
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• 제32권2호
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• pp.203-211
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• 2003

A new result of weak convergence of the empirical process is established for a stationary ${\phi}-mixing$ sequence of random variables, which relaxes the existing conditions on mixing coefficients. The result is basically obtained from bounds for even moments of sums of ${\phi}-mixing$ r.v.'s useful for handling triangular arrays with entries decreasing in size.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1758-1760
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• 2008

Under typical operating conditions, flows in microfluidic devices are laminar and molecular diffusion across the channels is slow, which makes an efficient mixing in microfluidic devices difficult to achieve. The mechanism to achieve effective mixing in laminar flows is that of repetitive stretching and folding. Essential is to generate spatially periodic flows with crossing cross sectional streamlines. A mapping method is employed to analyze mixing in micromixers, enabling us to investigate the progress of mixing both qualitatively and quantitatively. The progress of mixing is characterized by a measure of mixing, called the discrete intensity of segregation. The mapping method is applied to mixing in such micromixers as the staggered herringbone mixer, the barrier embedded micromixer, and the three-dimensional serpentine channel to demonstrate the capability of the numerical scheme to tackle general mixing problems in microfluidic devices.

• 충청수학회지
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• 제23권1호
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• pp.127-136
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• 2010

For the maximum partial sum of linear process generated by a doubly infinite sequence of identically distributed $\rho$-mixing random variables with mean zeros, a complete convergence is obtained under suitable conditions.