• 제목/요약/키워드: kinetic equation

검색결과 527건 처리시간 0.018초

강우 운동에너지식에 따른 한국의 강우침식인자 평가 (Evaluation of Rainfall Erosivity in Korea using Different Kinetic Energy Equations)

  • 이준학;신주영;허준행
    • 한국토양비료학회지
    • /
    • 제44권3호
    • /
    • pp.337-343
    • /
    • 2011
  • A particular empirical equation for rainfall kinetic energy is needed to compute rainfall erosivity, calculated by the annual sum of the product of total rainfall energy and maximum 30-min rainfall intensity. If rainfall kinetic energy equation was different, rainfall erosivity will be produced differently. However, the previous studies in Korea had little concern about rainfall kinetic energy equation and it was not clear which rainfall kinetic energy is suitable for Korea. The purpose of this study is to analyze and evaluate the difference of the rainfall erosivity based on different rainfall kinetic energy equations obtained from previous studies. This study introduced new rainfall erosivity factors based on rainfall kinetic energy equation of Noe and Kwon (1984) that is only regression model developed in Korea. Data of annual rainfall erosivity for 21 weather stations in 1980~1999 were used in this study. The result showed that rainfall erosivity factors by the previous equations had been about 10~20% overestimated than rainfall erosivity by Noe and Kwon (1984)'s equation in Korea.

이상난류제트 유동에서 고체입자 난류확산의 수치모델에 관한 연구 (Study on the numerical models of turbulent dispersion of solid particles in a two-phase turbulent jet flow)

  • 양선규;최영돈
    • 대한기계학회논문집
    • /
    • 제11권1호
    • /
    • pp.1-18
    • /
    • 1987
  • 본 연구에서는 입자가 부상된 이상난류제트유동에 Einstein의 확산모형, Pes- kin모형, 3-방정식 모형, 4-방정식 모형, 대수응력모형 등을 적용하여 해석하고 각 모 형들의 결과를 비교 분석하였다. 이상난류유동의 수치해석에서 공기는 제1유체유동 으로 하고 첨가되는 고체분말의 흐름은 밀도(.rho.$_{p}$), 층류동점성계수(.nu.$_{p}$), 과점성계수(.nu.$_{pt}$ )를 갖는 제2유체유동의 흐름으로 간주하였다.

선반주축계의 동특성 향상에 관한 연구 -주축대와 베드의 보울트 결합을 중심으로- (A Study on the Improvement of Dynamic Characteristics of Spindle-Work System in Lathe - Focused on the Bolt Juint between Headstock and Bed -)

  • 신용호;박태원;홍동표;정인성
    • 대한기계학회논문집
    • /
    • 제12권1호
    • /
    • pp.1-7
    • /
    • 1988
  • 본 연구에서는 컬럼모델을 보울트로 고정할 때 접합면에 알루미늄판, 황동판, 스테인리스판 등을 삽입하고 정적강성과 동적특성을 검토하여 이것을 기초로 공작물- 주축대-공구로 형성되고 있는 사이클중에서 선반의 주축대와 베드를 연결하는 결합부에 모델실험을 사용한 게재물을 삽입하고 선반구축계의 동적특성을 검토하였다.

폐기물로부터 메탄발생량 예측을 위한 Sigmoidal 식과 1차 반응식의 통계학적 평가 (Statistical Evaluation of Sigmoidal and First-Order Kinetic Equations for Simulating Methane Production from Solid Wastes)

  • 이남훈;박진규;정새롬;강정희;김경
    • 유기물자원화
    • /
    • 제21권2호
    • /
    • pp.88-96
    • /
    • 2013
  • 본 연구의 목적은 고형폐기물의 메탄발생 특성을 나타내기 위한 1차 반응식과 S형태 식들의 적합성을 평가하는 것이다. S형태 식은 수정 Gompertz와 Logistic 식을 사용하였다. 모델의 적합성을 평가하기 위해 잔차제곱합, 표준제곱근 오차, Akaike's information criterion 등의 통계분석을 실시하였다. AIC (Akaike's information criterion)는 모델의 변수 개수 차이에 따른 모델 적합성을 비교하기 위하여 적용하였다. 1차 반응식의 경우 지체기를 고려하지 않을 때보다 고려하였을 경우 잔차제곱합과 표준제곱근 오차는 감소하는 것으로 나타났다. 그러나 1차 반응식의 경우 S형태 식보다 AIC가 상대적으로 높게 나타났다. 이는 S형태 식이 1차 반응식보다 메탄발생특성을 나타낼 때에 더욱 적합한 것으로 사료된다.

생전분을 당공여체로 한 Stevioside의 당전이 반응의 동력학적 해석 (Kinetic Analysis of Transglycosylation Reaction of Stevioside Using Raw Starch as a Glycosyl Donor)

  • 박동찬;백승걸이용현
    • KSBB Journal
    • /
    • 제9권2호
    • /
    • pp.108-114
    • /
    • 1994
  • 분쇄마찰매치 함유 불균일상 효소반응계에서 생전분을 당공여체로 한 stevioside의 당전이 반응의 kinetics에 관한 연구를 수행하였다. 생전분으로부터 CD를 생서하는 과정과 생성된 CD와 stevioside가 random sequenrial bireactant ,echanism으로 반응하여 당전이 equation을 유도하였다. 또한 유도된 반응식의 각종 kinetic constants을 평가하였다. 유도된 반응식을 Runge-Kutta integration법으로 계산하였으며, 계산 결과를 실험치와 비교하여 유도식의 효용성을 검토하였다. 유도된 kinetic equations는 당공여체인 생전분의 농도, stevioside의 농도, 그리고 중간산물인 CD의 농도 변화를 비교적 정획히 표시할 수 있었으며, 고효율 당전이 효소반응기 개발에 활용될 것이다.

  • PDF

염료감응 태양전지용 루테늄 금속착체 염료의 이산화티타늄 전극에 대한 동적 흡착 연구 (Adsorption Kinetic Study of Ruthenium Complex Dyes onto TiO2 Anodes for Dye-sensitized Solar Cells (DSSCs))

  • 안병관
    • 한국전기전자재료학회논문지
    • /
    • 제24권11호
    • /
    • pp.929-934
    • /
    • 2011
  • The adsorption kinetic study of ruthenium complex, N3, onto nanoporous titanium dioxide ($TiO_2$) photoanodes has been carried out by measuring dye uptake in-situ. Three simplified kinetic models including a pseudo first-order equation, pseudo second-order equation and intraparticle diffusion equation were chosen to follow the adsorption process. Kinetic parameters, rate constant, equilibrium adsorption capacities and related coefficient coefficients for each kinetic model were calculated and discussed. It was shown that the adsorption kinetics of N3 dye molecules onto porous $TiO_2$ obeys pseudo second-order kinetics with chemisorption being the rate determining step. Additionally the heterogeneous surface and the pore size distribution of porous $TiO_2$ adsorbents were also discussed.

Management of Discon tinuous Reconstruction In the Evolution Stage of Kinetic Scheme

  • Ohwada Taku;Kobayashi Seijiro
    • 한국전산유체공학회:학술대회논문집
    • /
    • 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
    • /
    • pp.189-190
    • /
    • 2003
  • A New kinetic scheme for the compressible Navier-Stokes equations is developed. While the conventional approach, such as KFVS scheme, employs the splitting algorithm and computes the numerical flux on the basis of the collisionless equation, the present approach employs the splitting algorithm in the evaluation of the numerical flux, where the collision effect is explicitly taken into account. However, the initial condition employed in the computation is slightly different from the conventional Chapman-Enskog NS distribution function. The present study also reveals the background of the existing kinetic schemes. such as the KFVS scheme and Gas-Kinetic BGK scheme.

  • PDF

A GENERALIZATION OF THE KINETIC EQUATION USING THE PRABHAKAR-TYPE OPERATORS

  • Dorrego, Gustavo Abel;Kumar, Dinesh
    • 호남수학학술지
    • /
    • 제39권3호
    • /
    • pp.401-416
    • /
    • 2017
  • Fractional kinetic equations are investigated in order to describe the various phenomena governed by anomalous reaction in dynamical systems with chaotic motion. Many authors have provided solutions of various families of fractional kinetic equations involving special functions. Here, in this paper, we aim at presenting solutions of certain general families of fractional kinetic equations using Prabhakar-type operators. The idea of present paper is motivated by Tomovski et al. [21].

유출입의 원리에 의한 물질대사와 광합성능에 관한 동력학적 연구 (The Sigmoid Kinetics of Mass-action and Photosynthesis based on Influx and Efflux in a Plant Bio-system)

  • 장남기
    • The Korean Journal of Ecology
    • /
    • 제1권1호
    • /
    • pp.3-10
    • /
    • 1977
  • The sigmoiod kinetics of mass-action in a biosystem have been studied by theoretical bases on the carrier hypothesis of influx and efflux of substrates. The sigmoid kinetic equations of assimilation and dissimilation rates indicate that each trophicfactor and each bio-factor behave according to the sigmoid kinetic equation and the bell shape case, and all of them are multiplicative. The general sigmoid kinetics of mass-action is given by the equation (30) which is determined by the total of the equation (28) of the assimilation rate and the equation (29) of the dissimilation rate. The sigmoid kinetic model of photosynthesis has been derived from the general equation of the sigmoid kinetics of mass-action.

  • PDF

잠수함 난류항적 기술을 위한 무차원 난류 에너지 분포함수 B(ξ) 예측 (Analytical Solution of Non-dimensional Turbulent Kinetic Energy Distribution Function in the Turbulnet Wake behind a Submarine)

  • 이용철
    • 한국군사과학기술학회지
    • /
    • 제18권1호
    • /
    • pp.31-36
    • /
    • 2015
  • To describe turbulent wake behind a submarine, it is very important to know turbulent kinetic energy distributions in the wake. To get the distribution is to solve the turbulent kinetic energy equation, and to solve the equation, it is needed both information of ${\lambda}$ and ${\sigma}$ which define physical characteristics of the wake. This paper gives analytical solution of the equation, which is driven from $8^{th}$ order polynomial fitting, as a function of given ${\lambda}$, even though there is no information of ${\sigma}$. In comparison between numerical solution(i.e. exact solution) and analytical solution, the relative errors between them are less than to 5% in the range of 0 < ${\xi}$ < 0.95 in most given ${\lambda}$.