• Title/Summary/Keyword: mixing ratio

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Cloud Forecast using Numerical Weather Prediction (수치 예보를 이용한 구름 예보)

  • Kim, Young-Chul
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.15 no.3
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    • pp.57-62
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    • 2007
  • In this paper, we attempted to produce the cloud forecast that use the numerical weather prediction(NWP) MM5 for objective cloud forecast. We presented two methods for cloud forecast. One of them used total cloud mixing ratio registered to sum(synthesis) of cloud-water and cloud-ice grain mixing ratio those are variables related to cloud among NWP result data and the other method that used relative humidity. An experiment was carried out period from 23th to 24th July 2004. According to the sequence of comparing the derived cloud forecast data with the observed value, it was indicated that both of those have a practical use possibility as cloud forecast method. Specially in this Case study, cloud forecast method that use total cloud mixing ratio indicated good forecast availability to forecast of the low level clouds as well as middle and high level clouds.

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A study on optimal drive waveform and optimal gas mixing ratio of Plasma Display Panel (AC 플라즈마 디스플레이 패널에서의 최적 구동 파형 및 최적 가스 흔합비에 관한 연구)

  • Choi, Hoon-Young;Park, Hun-Gun;Lee, Seok-Hyun
    • Proceedings of the KIEE Conference
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    • 1997.07e
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    • pp.1721-1723
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    • 1997
  • In AC Plasma Display Panel(PDP), serious problems are low radiation brightness and very high discharge voltage. To solve these problems, it is necessary to obtain optimal frequency of drive waveform and optimal gas mixing ratio. This paper presents firing voltage and sustain voltage as frequency of waveform and gas mixing ratio, and proposes optimal frequency of drive waveform and optimal gas mixing ratio.

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Effect of Water Content Change of Soft Clay on Strength of Solidification Agent Treated Soil (연약점토의 함수비 변화가 고화처리토의 강도에 미치는 영향)

  • 김광빈;이용안;이광준;김유성
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.553-560
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    • 2002
  • The improvement effect of soft ground is estimated by unconfined strength mainly. The unconfined strength of solidification agent treated soil is likely to vary with ununiformed mixing ratio and water content change of in-situ ground place by place. So, it is unreasonable to apply a solidification agent mixing ratio obtained from laboratory test results on all over the soft ground. In this study, it was analysed how the unconfined strength would be effected by the water content of soft ground. For this study, a series of unconfined compressive tests are peformed on various water content soil samples. The test results showed that the strength was fallen to 30∼80% by two times increase of water content approximately, This means that strength of solidification agent treated soil is influenced greatly by water content of raw soft ground and mixing ratio of solidification agent. It was suggested that the method how to decide the mixing ratio with soft ground water content.

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Abnormal Discharge Characteristics of Fluorescent Lamp

  • Lee, Chang-Ho;Kang, Jae-Kyung;Jang, Eun-Seok;Kim, Jae-Bum;Park, Joon-Ha;Shin, Jong-Keun;Chung, In-Jae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.1425-1427
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    • 2009
  • In this paper, we investigated influence of gas pressure and gas mixing ratio on the abnormal discharge characteristics of fluorescent lamp. Abnormal discharge characteristics have been examined by changing inner gas pressure and mixing ratio. As the inner gas pressure and mixing ratio increase, the occurrence of abnormal discharge was delayed. It was found out that the occurrence of abnormal discharge is sufficiently delayed at the optimized inner gas pressure and mixing ratio.

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An Experimental Investigation on Spray Behavior of Biodiesel and DME on Blended Ratio in High Temperature and Pressure Ambient Conditions (고온 고압 분위기 조건에서 바이오 디젤과 DME의 혼합비에 따른 분무특성에 관한 연구)

  • Bang, Seung-Hwan;Chon, Mun-Soo;Lee, Chang-Sik
    • Journal of ILASS-Korea
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    • v.15 no.1
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    • pp.17-24
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    • 2010
  • The objective of this work is to analyze the macroscopic behavior of spray and injection characteristics on the DME blended biodiesel at different mixing ratios by using spray visualization and injection rate measurement system. The spray images were analyzed to a spray tip penetration, a spray cone angle and a spray area distribution at various mixing ratio of DME by weight. The influence of different injection pressure and ambient pressure on the fuel spray characteristics are investigated for the various injection parameters. In order to analyze the injection characteristics of test fuels, the fuel injection rate is measured at various blending ratio. The variation of viscosity of the blended fuel by the mixing of DME fuel shows the improved effect of spray developments. Also, it was found that the injection quantities of high blended ratio were larger than that of lower blended fuel. Also, higher blending fuel showed a faster evaporation than that of mixing ratio of test fuel because kinetic viscosity was changed by blending ratio.

Optimization of β-Cyclodextrin Recycling Process for Cholesterol Removal in Cream

  • Kwak, H.S.;Suh, H.M.;Ahn, J.;Kwon, H.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.4
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    • pp.548-552
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    • 2001
  • This study was designed to find optimum conditions of four different factors (ratio of solvent to cholesterol-$\beta$-cyclodextrin complex, mixing speed, mixing temperature, and mixing time) for cholesterol dissociation in cream. Using the ratio of 6 to 1 (solvent to the complex) showed the highest cholesterol dissociation rate (82.50%) when mixed at 100 rpm at $50^{\circ}C$ for 1 h. Mixing speed did not significantly affect the cholesterol dissociation. Also, mixing time appeared to be insignificant. The optimum mixing temperature was $50^{\circ}C$ and mixing at $40^{\circ}C$ resulted in a significantly lower rate, compared with that at $50^{\circ}C$. In a subsequent experiment, using recycled $\beta$-cyclodextrin only showed 75.07% of cholesterol removal in cream, while the mixture of recycled to unused $\beta$-CD with the ratio of 6 to 4 increased cholesterol removal to 95.59%, which is highly close to that of 100% unused $\beta$-CD.

A study on propagation of uncertainties for a mixing ratio calculation by seawater intrusion (해수침투 발생 시 혼합비 계산의 오차에 관한 연구)

  • Lee, Jeonghoon
    • Journal of the Geological Society of Korea
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    • v.54 no.5
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    • pp.579-584
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    • 2018
  • It is crucial to determine a mixing ratio using an end-member mixing analysis when there is seawater intrusion. In this study, an error from the calculation of the mixing ratio between seawater and freshwater based on the principles of uncertainty was determined. I present the errors in the calculated mixing ratios as a function of the chemical difference between the mean seawater concentrations and standard deviations. The error is caused by: (1) the mixing ratio between seawater and freshwater; (2) the difference between the mean concentration and the standard deviation; and (3) the difference of the tracer concentration between freshwater and seawater (inversely). In particular, the error may determine hydrogeochemical process (either precipitation or dissolution) when a value of ionic delta (difference between measured and theoretical concentration) is close to zero during cation exchange by seawater intrusion.

Effect of the Mixing Extraction of Perilla Seed and Peanut on Physicochemical Characteristics and Oxidative Stability of Perilla Oil (들께와 땅콩의 혼합 채유가 들기름의 이화학적 특성 및 산화안정성에 미치는 영향)

  • 권용주;김충기;오현화
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.6
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    • pp.1212-1219
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    • 1999
  • The oils were extracted from the mixture of roasted(for 20 min at 190oC) perilla seeds(RPS) and roasted (commercially) peanuts(RPN) by solvent extraction(SE) and mechanical expression(ME). The effects of mixing ratio on physicochemical characteristics and oxidative stability of their oils were investigated. Yields of both SE and ME oils were increased as the RPN ratio in the mixture increased. In all the SE and ME oils, the major fatty acids were oleic, linoleic and linolenic acid, and total saturated fatty acids increased gradually, but total unsaturated fatty acids decreased gradually as the RPN ratio in the mixture was increased. The specific gravity and refractive index of both SE and ME oils decreased as the RPN ratio in the mixture was increased. Acid value, saponification value and iodine value of SE oils decreased as the RPN ratio in the mixture increased, whereas acid value and iodine value of ME oils decreased and saponification value increased. The colors of ME oils were darker brownish than SE oils. The oxidative stability of SE oils was decreased as the RPN ratio in the mixture increased, whereas that of ME oils was increased. Sensory evaluation of all the oils extracted from the mixture with various mixing ratio showed significant differences in flavor, taste, color and overall acceptance(p<0.01). The oil extracted from the mixture of the mixing ratio of 8:2(RPS:RPN) showed slightly higher preference regardless of extraction method.

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Effect of Fuel Mixing Ratio on Fuel Consumption in a Oil Fired Power Plant (중유화력발전소에서 바이오연료 혼합연소가 연료소비량에 미치는 영향)

  • Hong, Sangpil;Yoo, Hoseon
    • Plant Journal
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    • v.12 no.3
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    • pp.39-45
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    • 2016
  • Each of fuel consumption per hour was measured at the 320 MW and 380 MW generator output while changing mixing ratio of bio fuel oil to 50%, 80% and 100%. Fuel consumption per hour was increased from 11.0% to 20.4% as mixing ratio of bio fuel oil was changed from 50% to 100% at the 320 MW generator output comparing with fuel consumption per hour in case of bunker-C oil single firing. Fuel consumption per hour was also increased from 12.0% to 21.1% as mixing ratio of bio fuel oil was changed from 50% to 100% at the generator output 380 MW. Furthermore, it was confirmed that plant efficiency was decreased as mixing ratio of bio fuel oil was increased from 50% to 100% as a result that plant efficiency was calculated using the measured fuel consumption per hour, the generator output and the gross heating value.

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Mixing Performance of Unlike Doublet Impinging Liquid Jets (이중 충돌제트의 혼합 성능 연구)

  • Jo, Yong Ho;Lee, Seong Ung;Yun, Ung Seop
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.4
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    • pp.82-91
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    • 2003
  • Experiments to investigate the mixing performance of unlike doublet impinging jets are conducted. Reynolds number of simulants used in this study rages from 1.0 to 1.5 Cold flow test is performed to investigate the hydrodynamic effect and spray of the impinging jets are collected locally and calculated by using Rupe's mixing efficiency equation. Momentum exchanges and relative velocity ratio between two jets are taken as the main parameter to represent the effect of enlargement of the orifice diameter. As diameter ratio increases, the corresponding momentum ratio where maximum mixing efficiency occurs and relative velocity at the maximum mixing efficiency ranges 0.6 to 0.7, respectively. Penetration depth can be taken as a prominent parameter to estimate the mixing efficiency.