• Title/Summary/Keyword: flow property

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Listing, Patent and Valuation of Agricultural Company -Comparison and Analysis of Environmental-friendly Agricultural Company- (농기업의 상장 및 특허와 가치평가 -친환경 농기업의 비교분석을 중심으로-)

  • Yeo, Dong-Su;Hwang, Jae-Hyun
    • Korean Journal of Organic Agriculture
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    • v.21 no.1
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    • pp.33-48
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    • 2013
  • This work is for listing, patent, reasonable valuation of environmental-friendly agricultural company. In this study, agricultural company in environmental friendly industry that consider nature, customer's wellbeing and safe would be evaluated by DCF (Discounted Cash Flow) and ROV (Real Option Value). And company in environmental-friendly industry would be checked whether it is to be related and concerned to listing in the stock market and patent acquisition with the basis of company valuation. After then agricultural company value is evaluated with the consideration of growth in environmental-friendly industry, and company valuation comparison would followed about intellectual property right. It can be assumed that value of environmental-friendly agricultural company has low relation and concern to listing of stock market, and valuation would be increased through the intellectual property right such as patent, development or core search ability.

Thermophoretic Particle Deposition Around a Circular Cylinder in a Uniform Laminar Air Dlow (균일 층류유동중에 있는 원형 실린더 주위의 열영동에 의한 입자 부착)

  • Hong, Gi-Hyeok;Gang, Sin-Hyeong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.2
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    • pp.641-648
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    • 1996
  • Thermophoretic particle deposition on a circular cylinder in a uniform laminar air flow was numerically investigated using a control volume method based on the generalized non-orthogonal coordinate system. Variation of air properties due to the change of temperature was taken into account. Effects of variable property on the distribution of heat transfer and deposition rates of particle were discussed. A new correlation of thermophoretic particle deposition on a circular cylinder was proposed in the present study.

An Experimental Study on the Property of High Performance Concrete for Concrete Filled Tube with Addition Content of Steel Fiber (강섬유 첨가량에 따른 콘크리트 충전강관용 고성능 콘크리트 특성에 관한 실험적 연구)

  • Seo, Il;Hong, Seok-Beom;Yoo, Jo-Hyeong;Park, Hee-Gon;Kim, Woo-Jae;Lee, Jae-Sam
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.05a
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    • pp.213-214
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    • 2012
  • This paper presents basic study to develop high performance concrete for concrete filled tube with addition content of steel fiber. In this study, all mixtures was added to nylon fiber (1.5 kg/㎥) and steel fiber was mixed by 0, 20 and 40 kg/㎥ respectively. To evaluate the property of high performance concrete was used to various test methods which were slump flow, air content, U-box test, O-lot test and L-flow(to 300 mm, 500 mm). Also, compressive strength test was measured by ages.

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Study on a Separator for the All-vanadium Redox Flow Battery (바나듐 레독스-흐름 전지용 격막에 관한 연구)

  • Lee, Sang-Ho;Kim, Joeng-Geun;Choi, Sang-Il;Hwang, Gab-Jin;Jin, Chang-Soo
    • Membrane Journal
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    • v.19 no.2
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    • pp.129-135
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    • 2009
  • The cation exchange membrane using the block co-polymer of polysulfone and polyphenylenesulfidesulfone was prepared for a separator of all-vanadium redox flow battery. The membrane property of the prepared cation exchange membrane was measured. The thermal stability of the prepared cation exchange analyzed by TG showed a more stable than that of Nafion117. The lowest measured membrane resistance, equilibrated in 1mol/L $H_2SO_4$ aqueous solution, $0.96{\cdot}cm^2$ at 3 cc of CSA (chlorosulfuricacid) which was introduction agent of ion exchange group. Electrochemical property of all-vanadium redox flow battery using the prepared cation exchange membrane was measured. Electromotive force in 100% of state of charge was 1.4 V which was that of all-vanadium redox flow battery, and cell resistance in charge and discharge at each state of charge had a low value compared with that of all-vanadium redox flow battery using Nafion117.

Flow Properties of Doenjang (시판된장의 리올로지(Rheology) 특성에 관한 연구)

  • 양신철;김선화
    • Journal of Applied Tourism Food and Beverage Management and Research
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    • v.13 no.1
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    • pp.55-68
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    • 2002
  • Flow properties of doenjang samples at various total solid contents (30, 32, 34, 36, 38, 40%) were evaluated in this study. Flow properties of doenjang samples was determined by using Haake concentric cylinderical viscometer and Instron testing machine with capillary extrusion viscometer, and consistency index(K), and flow behavior index(n) was also determined from power models, and yield stress was derived form Casson models and vanes methods. Doenjang samples showed shear-thinning (pseudoplastic) fluid with small magnitude of flow behavior index(n) (n=0.30-0.55). Casson yield stress was from 2.11 to 64.02(Pa). Vane yield stress was more effective than casson yield stress in property of reactivation. Apparent viscosity was decreased with the increase in temperature and activation energy was in the range of 6.58 to 10.70 kJ/mole. From the capillary extrusion method, K and n was increased with the increase in solid content with good correlation with. The result revealed that capillary extrusion method is useful for measuring the flow properties of doenjang.

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Investigation of the 2013 Hadari Debris Flow in Korea Through Field Survey and Numerical Analysis

  • Choi, Junghae
    • The Journal of Engineering Geology
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    • v.28 no.3
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    • pp.341-348
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    • 2018
  • Landslides can be caused by localized intense rainfall. The loss of human lives and damage to property from landslides is increasing. However, little information exists on the movement and flow of sediment material at the time of rapid landslides. In this study, a field survey was conducted of landslides that occurred in 2013 in the Hadari area of Yeoju city in Korea. This was followed by numerical analysis. The purpose is to analyze the characteristics of a consequent debris flow and its movement at the time of failure. The results of the field survey and numerical analysis are consistent with each other. The maximum velocity of the debris flow was ~9.335 m/s and the maximum sediment thickness ~4.674 m. The latter is similar to the traces of debris flow observed in the field.

An Experimental Study on Enhancement of Laminar Flow Heat Transfer in a Circular Pipe with Inserts (삽입물에 의한 관내 층류열전달 증진에 관한 실험적 연구)

  • 권영철;장근선;정지환
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.7
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    • pp.667-673
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    • 2000
  • In order to understand the laminar flow heat transfer enhancement by the swirl flow, the effects of heat transfer in a circular pipe with a twisted tape insert were investigated experimentally. In the present study, the uniform heat flux condition was considered. The laminar heat transfer correlations were developed using the least-square-fit from the surface temperature distribution of an electrically-heated pipe and flow property data. Average Nusselt number correlations with the twisted tape insert were expressed as a function of swirl parameter, Reynolds number and Prandtl number. In the case of the twisted ratio y = 6.05, the mean Nusselt number increased approximately 500% and the friction factor increased approximately 300%, compared to the case of the empty pipe, respectively.

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Micro PIV Measurement of Two-Fluid Flow with Different Refraction Indices (미소입자영상유속계를 이용한 굴절률이 다른 두 유체 유동 측정)

  • Kim, Byoung-Jae;Liu, Ying Zheng;Sung, Hyung-Jin
    • 유체기계공업학회:학술대회논문집
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    • 2003.12a
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    • pp.107-114
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    • 2003
  • The influence of property difference in refraction index on micro PIV measurement of two-fluid flow in a microchannel was analyzed. The difference of measurement planes in two fluids would bring misunderstanding of the physics. The objective-imaging system for two-fluid flow measurement was presented, and the condition for measurement of valid velocity profile across two-fluid interface was derived. A micro PIV experimental system was set up to measure two-fluid flow inside a Y-shape microchannel. Under the conditions, three cases of two-fluid flow of glycerol solutions at different concentration (${\phi}$), e.g., (${\phi}=0\;and\;{\phi}=0.2,\;{\phi}=0.1\;and\;{\phi}=0.5,\;{\phi}=0\;and\;{\phi}=0.6$, were measured. Close agreement of experimental and numerical results was found.

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Flow Properties of Traditional Kochujang : Effect of Fermentation Time (숙성기간에 따른 재래 고추장의 유동성 변화)

  • 유병승;최원석;류영기
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.3
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    • pp.554-558
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    • 1999
  • Flow properties of traditional kochujang at various fermentation times(0~12 weeks) were determined with rotational cylindrical(RC) and serrated plate plate(PP) viscometer. Magnitudes of consistency index(K) of power law model and Cassson parameters(yield stress and viscosity) measured by PP viscometer were higher than those using RC viscometer. All kochujang samples during fermentation were much shear thinning with values of flow behavior index(n) as low as 0.2~0.34. K value and Casson yield stress measured by PP viscometer had good correlations(r=0.94; r=0.91) with fermentation time. No significant changes in flow model parameters measured by RC viscometer were observed for kochu jang during fermentation. Magnitudes of flow model parameters measured by PP viscometer more closely correlated with fermantation times of kochujang than did RC viscometer.

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Properties of the Load-Sensing Hydraulic System from a Viewpoint of Control (제어관점에서의 부하감지형 유압시스템의 특성)

  • 김성동
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.3
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    • pp.738-750
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    • 1994
  • The load-sensing hydraulic system which was developed to improve energy efficiency of conventional hydraulic systems has its own properties. The instability of system responses, linearity of a servo valve, robustness for variation of external load, and dynamic interference between hydraulic motors are such properties which have much to do with control properties of the system. The load-sensing hydraulic system has instability tendancy because the load-sensing mechanism makes a positive feedback loop between the motor part and the pump part. A flow property of the servo valve can be said to be linear because the flow through the valve has nothing to do with a load pressure and the flow is strictly proportional to a valve opening which is adjusted by a valve command signal. The resultant control property can be said to be robust because the steady-state control performance is independent to the load actuated on the motor shaft. In the case when one pump simultaneously drives more than two hydraulic motors, the pump outlet pressure is determined by a hydraulic motor of the largest load pressure among all of the hydraulic motors, and, thus, the other motors are dominated by the largest load pressure. That is, the other motors can be said to be interfered by the motor of the largest load pressure.