• Journal of Biosystems Engineering
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• v.2 no.1
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• pp.1-6
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• 1977

The dilution of crankcase oil with unburned portions of the fuel during operating is one source of the oil contaminations which will reduce engine life.It has been learned that major causes of oil dilution may be the result of using impure fuels which were mixed with water, dust, and some others, but very little was known about this. This study was conducted to develop a more intimate understanding about oil dilution of the farm kerosene engine while using impure fuel mixed with expecially diesel. Fuels being used in this study were 9 kinds of mixed fuels, kerosene and diesel. Farm kerosenen engine of 10 P.S. was tested at no-load of 1000 and 2000 rpm., such as 1/4, 2/4, 3/4, 4/4, and 11/10 loads for understanding about oil dilution of keresene engine.The result of this study are summarized as follows : 1. The amounts of oil dilution of the engine being tested was increased with increase in the applied loads and the contents of diesel in the mixed fuels when using fuels other than kerosenen and diesel, whereas at $D_100$ fuel the comount of oil dilution decreased in some cases. The lowest value was measured to be 20 cc/hr, at $K_90$ fuel of no-load condition, and the highest value to be 293cc/hr. at $K_{10}$ fuel of 4/4 load condition. 2. When the engine was operated at no-load condition, the amount of oil dilution at 100rpm. was much more than at 2000 rpm. 3. Because the fuel consumption and the oil dilution showed a similar tendency along the applied loads, the excessive fuel consumption of engines was supposed to be one of the important factors affecting oil dilution. 4. The temperature of crankcse oil was varied invesely with oil dilution, but they were not thought to be factors to determine each other variable. 5. The tested engine could be operated with high percentage of diesel mixed fuel from no-load condition to fully loaded condition, but it would be impossible to operate the engine for long hous continuously due to excessive speed fluctuation.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.1
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• pp.71-75
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• 2001

Linear regression analyses between the electrical conductivity of the saturation-paste extract. ECe, and the electrical conductivity of the 1:5 soil extract, EC1:5, for different soils yielded different dilution factors, or slopes with significant $r^2$ values from 0.842 to 0.905. The dilution factor was inversely proportional to the cation exchange capacity of soil which reflected textural difference. The dilution factors recommended for different textural classes ranged from 6.44 for clay soil to 12.29 for sandy soil based on the CEC's of the textural classes among 350 surface soils recorded in the Taxonomical Classification of Korean Soils except volcanic ash derived soils. Though saturation percentage of the saturation-paste of the soils in this study, CEC should be taken into account for dilution factor between ECe and EC1:5, and the suggested dilution factors might be reasonable estimate for the soil textural classes.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.1
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• pp.46-51
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• 2006

Phosphorus accumulation in fertilized soils becomes serious problem for agriculture and the environment. In this investigation, we conducted a laboratory scale investigation to find the most desirable displacement methods of the adsorbed phosphate onto the soil particle surfaces. Soil samples which contained high amount of phosphate were collected at two different depths (0-10 cm and 10-20 cm) from four locations at the moderate highland located in Nonsan, Chungnam. To observe the mobilization of solid-phase phosphate, soil samples were equilibrated with oxalic acid solutions ranging from $10^{-5}$ to $10^{-1}cmol\;L^{-1}$ with the dilution factors of 1:1, 1:2.5, 1:5, 1:10, and 1:20. The mineralized P sharply increased as the concentration of oxalic acid was greater than $5{\times}10^{-4}cmol\;L^{-1}$ under dilution factors of 1:1, 1:2.5, and 1:5. The breaking concentration of oxalic acid was lowered to $10^{-4}cmol\;L^{-1}$ and $5{\times}10^{-5}cmol\;L^{-1}$ for dilution factors of 1:10 and 1:20, respectively. The curve fit obtained from the graph can be described by exponential growth when the dilution factors were 1:1, 1:2.5, and 1:5 while the sigmoidal shape for 1:10 and 1:20, showing the mineralization of P were significantly dependent on the dilution factor.

• Journal of Radiation Protection and Research
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• v.23 no.1
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• pp.1-6
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• 1998

A diffusion model of radioactive liquid effluents is developed and applied for YGN NPP's site, based on the Gaussian plume type model. Due to the complexity of oceanic diffusion characteristics of YGN site, a simple and reliable statistical model based on Reg. Guide 1.113 is developed. Also, a computer code package to calculate dilution factors as a function of plant operation conditions and pathway of radioactive materials. A liquid effluents diffusion model is developed by dividing the diffusion range into two categories, i. e, a near field mixing region and a far field mixing region. In the near field, the initial mixing is affected by a buoyance force, a high initial turbulence and momentum which is characterized by a plant operation condition and environmental conditions. The far field mixing is similar to gaseous effluents diffusion. So, beyond the near field region, wellknown Gaussian plume model was adopted. A different area averages of Gaussian plume equation was taken for each radioactive exposure pathway. As a result, we can get different dilution factors for different pathways. Results shows that present dilution factors used for YGN ODCM is too much overestimated compared with dilution factors calculated with the developed model.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.301-303
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• 2014

Flameless combustion, well known as MILD (Moderate Intensity Low oxygen Dilution) combustion or CDC(Colorless Distributed Combustion), is considered as one of the promising technology for achieving low NOx and CO emissions with improving thermal efficiency of combustion system. In this paper, the effects of exhaust gas dilution rate on formation of flameless combustion of liquid fuel were analyzed using three-dimensional numerical simulations for application of gas turbine combustor with high power density. Results show that the local high temperature region was decreased and flame temperature was spatially uniformly distributed due to higher dilution rate of burnt gas as similar pattern of gas phase flameless combustion. But the evaporation and mixing process of liquid fuel are found to be another important factors for formation of flameless combustion.

• 한국기계연구소 소보
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• s.19
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• pp.31-42
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• 1989

To investigate design factors of dilution ventilation system, numerical analysis of air contamination flow and concentration distribution have been made, by using the low Reynolds number turbulent model. And flow visualization and measurement of particle concentration for that model also have been made. By comparing of these results we have secured the essential data for the adequate counterplan of dilution ventilation system. The results of this study are as follows: 1) Inlet should be located near the wall for the prevention of the formation of the recircula¬tion zone. 2) In case of natural exhaust, air contamination flow is driven to the far outlet from the inlet. 3) It is favorable for dilution to make turbuence as much as possible.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.11 no.2
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• pp.116-126
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• 1999

In this paper, we have studied the seasonal vanatIons of near-field dilutions of wastewater discharged from the submerged mutiport-diffuser in Masan Bay. Seasonal changes of temperature and salinity, and tidal currents were measured at 16 stations in Masan Bay. Based on the observed ambient field data, the seasonal changes of near-field dilutions due to ambient current and density fields were calculated by CORMIX model. Because of the shallow ambient water depth of 15 m, the density profiles are isopycnal in autumn and winter seasons, in which the dilution factors were the highest, 168 with the strong spring-tidal current and 110-120 with the weak neap-tidal current. As the season changes from spring to summer, the dilution factors are considerably reduced by the factor of 2 as the thermocline is getting deepened up to Sm in depth in summer. In the case of a weak ambient current, the dilution factor in summer was reduced to 1/4 of the dilution in winter. However, with strong ambient current the difference between summer and winter dilutions becomes relatively small by 30%. The results indicate that the seasonal variation of near-field dilution is very large up to 4 times with a weak neap-tidal current, but its variations become small under a strong ambient current of spring tide in MasanBay.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.103-104
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• 2000

우리나라의 악취배출 허용기준에는 직접관능법, 공기희석관능법 및 기기분석법에 의한 측정과 규제 기준을 제시하고 있다. 직접관능법의 경우 신속하고 간편하여 현장에서 바로 판정을 내릴 수 있다는 점에서 부지경계선상에서의 악취의 평가수단으로 이용되어 현재까지 많은 평가서에 측정결과를 제시하고 있다. 그러나 직접관능법에 의한 평가결과가 규제치를 넘어 법적 조치가 이루어진 사업장은 거의 없는 듯하다. (중략)

• Journal of Oriental Neuropsychiatry
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• v.15 no.2
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• pp.89-101
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• 2004

Objective : The present experiments were designed to study on the immune-enhancing effect of Mountain grown ginseng, Mountain cultivated ginseng, and Panax ginseng Method : In order to compare the immune-enhancing effect of moutain grown ginseng, moutain cultivated ginseng and Panax ginseng, the study was done through the forced swimming test (FST), measurement of T helper Th1, Th2 cytokines and fatigue related factors. Result : Moutain grown ginseng and panax ginseng decreased the immobility time in the FST compared to the control. Glucose, blood urea nitrogen (BUN), creatinine, lactate dehydrogenase (LDH) and Total-protein (T-protein) in serum were investigated. The serum achieved from ginseng administered mouse showed higher BUN, T-protein than the control. moutain grown ginseng administered group showed lower LDH than the control group. moutain grown ginseng administered mouse showed higher glucose than the control. Creatinine was same in either experimental or control group. Ginseng-induced cytokine production in human T-cell line, MOLT-4 cells and mouse peritoneal macrophages were compared. Moutain cultivated ginseng (10-4 dilution) and panax ginseng (10-3 dilution) were increased the interferon $IFN-{\gamma}$ production compared with media control (about 1.6-fold P<0.05) at 48 h. Moutain grown ginseng (10-4 dilution) was increased the $IFN-{\gamma}$ and interleukin IL-4 production compared with media control (about l.4-fold for $IFN-{\gamma}$ and 1.6-fold for IL-4 P<0.05) at 48 h. Moutain grown ginseng (10-3 dilution) and moutain cultivated ginseng (10-4 dilution) were increased the turmor necrosis factor $TNF-{\alpha}$ production compared with $rIFN-{\gamma}$ treated cells (about 1.9-fold for $TNF-{\alpha}$ P<0.05), respectively. Moutain cultivated ginseng (10-3 dilution) was increased the IL-12 production compared with $rIFN-{\gamma}$ treated cell (about 1.7-fold for IL-12 P<0.05). Conclusion : These data suggest that three different three kinds of ginseng act on immune responses in different aspects.

• Microbiology and Biotechnology Letters
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• v.16 no.6
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• pp.510-516
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• 1988

The effects of input substrate concentration and dilution rate on mass transfer resistance in the operation of immobilized cell reactors were investigated using Rhodospirillum rubrum KS-301 immobilized by Ca alginate as reactor element and glucose as growth-limiting substrate. The kinetic parameters were obtained to estimate effectiveness factors. In the packed-bed reactor, internal mass transfer resistance was predominating although external resistance could not be neglected. The overall effectiveness factor was decreased with increase of dilution rate. In the continuous stirred-tank reactor, external resistance was nearly neglected and the overall effectiveness factor was not affected by dilution rate. In this experiment the overall effectiveness factors in PBR and CSTR were estimated to be 0.70 and 0.71 at D$_{i}$ = 0.2/h, R = 0.15 cm, and S$_{i}$ : 1.0g/L, respectively.