遷移區域을 考廬한 對流熱傳達에 관한 硏究

裵信徹 단국대학교 1982 論文集 Vol.16 No.-

A comparative study on the heat transfer in the aerodynamic heating for cases of two-region model and three-region model is presented; the two region model consists of the laminar and turbulent regions, while the three region model includes the laminar, transition and turbulent regions. For unit Reynolds numbers of 8×10 exp (6) and 4×10 exp (7) the onset transition Reynolds numbers are 1.94×10 exp (6) and 5.36×10 exp (6), respectively. It may be said that the onset transition Reynolds number increases as the unit Reynolds number increases. Mach number influences more on the end transition Reynolds number than on the onset transition Reynolds number. Transition for Μ=4.5 occurs earlier than for Μ=2.5 by 21%. A relationship for the end transition Reynolds number of flat plate and cone may be expressed by the following formula and the formula may be used to correlate the existing experimental data within ±12%. 〔(Rete)_δ〕_c/〔(Rete)_δ〕_p=3.4-0.3Μ_δ Heat transfer for the case of two-region model is larger than that for three-region model. The difference of heat transfer between the two models decreases as the Mach number increases.

동결 건조기의 최적 운전 기법

裵信徹,李近熙 단국대학교 1993 論文集 Vol.27 No.-

The problem of operating a freeze dryer to obtain a fixed final moisture content in minimum time is formulated as an optimal control problem. The energy radated from the heat plate, and total pressure in drying chamber are considered as control variables. Constraints are placed on the system state variables by the scorch point of the dried product and the melting point of the frozen interface. The optimum control policy at the beginning of the run, when neither of the two temperature constraints is active, has been establishen through a theoritical analysis under pseudo-steady state assumptions. For certain cases the nature of the overall optimum control policy has been found. The numerical solution of the steady and nonsteady state problem indicates that if a control policy is optimum for the steady state problem, then this control policy is also optimum for the nonsteady state problem.

유압관로내 원통형 초크의 분류영역에서 맥동유동의 거동과 유동특성에 관한 연구

배신철,모양우,Moh, Y. W. 대한기계학회 1995 대한기계학회논문집 Vol.19 No.11

Cylindrical chokes are used widely as components of hydraulic equipments. The dynamic characteristics between flowrate and pressure drop through the cylindrical chokes were discussed by the frequency characteristics of the chokes. It was assumed no pressure recovery occurred near the downstream of the choke. The pulsating jetflow from the outlet of cylindrical chokes show very complex behaviours which are quite different from the steady jet flow but it's not clarified quantitatively. In order to utilize the chokes as a flowmeter, it is indispensable to discuss the estimation of the dynamics of pressure drop in the downstream jetflow region of cylindrical chokes. In this experimental study, it is clarified that the reattachment length depended on pressure wave is compared with it depended on velocity wave. A pulsating flow is verified by visualization method. In the present study, the flow characteristic variables of laminar pulsating flow are investigated analytically and experimentally in a circular pipe. Characteristic parameters of the ratios of inertia(.PHI.$_{t,1}$) and viscous(.PHI.$_{z,1}$) term to pressure term are introduced to describe the flow pattern of laminar pulsating flow. flow.low.

도열병균(Magnaporthe grisea)의 Ribosomal DNA의 ITS II 부위 핵산 염기서열을 이용한 균주간 근연관계 비교

배신철,이신우,이인구,예완해,류진창 한국식물병리학회 1996 Plant Pathology Journal Vol.12 No.1

벼도열병균 14개 균주와 벼 이외 화본과 식물 도열병균 12개 균주를 대상으로 rDNA의 ITS II 부위를 증폭하여 그들의 핵산 구조 차이를 분석함으로 도열병균 균주간 분류를 시도하였다. 5.8S rDNA의 3`-말단 부위와 28S rDNA의 5`-말단 부위의 sequence 중 5`-CCCGGGAATTCGCATCGATCGATCGAATGAAGA-ACGCAGC-3`와 5`-CCCGGGATCCTCCGCTTATT-GATATGC-3`를 이용하여 PCR 증폭을 하였을 때 벼도열병균 14개 균주는 동일한 길이의 단일 밴드를 형성하였으며 벼 이외 화본과 식물 도열병균에서는 레드톱 식물로부터 분리한 도열병균만이 나머지 균주보다 38bp가 더 큰 길이를 가진 밴드를 형성하였다. PCR로 증폭된 DNA를 HaeIII와 MspI 제한효소로 절단하였을 때 벼도열병균 레이스간에는 제한효소 절단에 의한 전기영동 밴드 형태 차이를 관찰할 수 없었으나, 벼 이외 화본과 식물 도열병균 12개 균주는 3군으로 구분할 수 있었다. 벼도열병균 90=054와 강아지풀에서 분리한 도열병균 G90-5, 기장에서 분리한 G88-4, 바랭이에서 분리한 G88-5 그리고 레드톱에서 분리한 RT 균주의 ITS II 부위의 DNA 염기서열 비교 분석에 의하면 G88-4와는 다른 HaeIII와 MspI 제한효소 위치를 가지고 있었기에 제한효소 절단에 의한 전기영동 형태가 상이하였다. 또한 RT균주는 HaeIII와 MspI위치가 존재하지 않았다.

주파수의 변화에 따른 원형관로내 층류맥동유동의 속도와 압력의 분포

배신철,모양우,Bae, S.C.,Mo, Y.W. 대한설비공학회 1997 설비공학 논문집 Vol.9 No.4

In this paper, the fundamental equations are developed for the pulsatile laminar flow generated by changing the oscillatory flow with $0{\leq}f{\leq}48Hz$ into a steady one with $0{\leq}Re{\leq}2500$ in a rigid circular pipe. Analytical solutions for the wave propagation factor k, the axial distributions of cross-sectional mean velocity $u_m$ and pressure p are schematically derived and confirmed experimentally. The axial distributions of centerline velocity and pressure were measured by using Pitot-static tubes and strain gauge type pressure transducers, respectively. The cross-sectional mean velocity was calculated from the centerline velocity by applying the parabolic distribution of the laminar flow and it was confirmed by using the ultrasonic flowmeter. It was found that the axial distributions of cross-sectional mean velocity and pressure agree well with theoretical ones and depend only on the Reynolds number Re and angular velocity $\omega$.

Green函數를 利用한 熱擴散係數의 解析

裵信徹,金榮殷 단국대학교 1984 論文集 Vol.18 No.-

To determine the thermal diffusivity coefficient Green function was applied. With its derived results experiment was performed to find its coefficient with flash method technique. Copper alloy was used as an experimental material and rolling process was applied to produce different anisotropy. Anisotropic effect, increased with increase of percent reduction in thickness, prevented thermal conductivity and its characters were investigated with measured thermal diffusivity in experiment.

반구면경을 이용한 스펙트럼 방사율 측정법

배신철,오기수,Bae, Sin-Chul,Oh, Ki-Soo 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.6

It is studied that the measuring method of the spectral emissivity by using hemispherical mirror with an inclined observation hole. The in-service calibration method of mirror reflectivity is also dealed with. It is possible to apply this method on measuring emissivity of conductor or non-conductor.

과도탐침법을 이용한 액체의 열물성 동시측정

배신철,김명윤,Bae, Sin-Cheol,Kim, Myeong-Yun 대한기계학회 1997 大韓機械學會論文集B Vol.21 No.2

The theoretical model for the transient probe method is the modified Jaeger model which is used perfect line source theory. The transient probe technique has been developed for the simultaneous determination of thermal conductivity, diffusivity and volumetric heat capacity of liquids. The Levenberg-Marquardt iteration method is adapted to obtain thermal property within nonlinear range. Experimental results of liquids were found to agree well with recommended thermal property data.

銅 및 알미늄材의 圧延時 圧延率과 熱流動方向에 따른 熱擴散係数의 變化에 関한 実験的 研究

裵信徹(S.C. Bae),朴喜鎔(H.Y. Pak),李用成(Y.S. Lee) 한국항공우주학회 1985 韓國航空宇宙學會誌 Vol.13 No.3

기후변화에 대응한 농업생명공학의 기회와 도전

장안철,최지영,이신우,이동헌,배신철 한국식물생명공학회 2011 식물생명공학회지 Vol.38 No.2

Considering that the world population is expected to total 9 billion by 2050, it will clearly be necessary to sustain and even accelerate the rate of improvement in crop productivity. In the 21st century, we now face another,perhaps more devastating, environmental threat, namely climate change, which could cause irreversible damage to agricultural ecosystem and loss of production potential. Enhancing intrinsic yield, plant abiotic stress tolerance, and pest and pathogen resistance through agricultural biotechnology will be a critical part of feeding, clothing, and providing energy for the human population, and overcoming climate change. Development and commercialization of genetically engineered crops have significantly contributed to increase of crop yield and farmer’s income, decrease of environmental impact associated with herbicide and insecticide, and to reduction of greenhouse gas emissions from this cropping area. Advances in plant genomics, proteomics and system biology have offered an unprecedented opportunities to identify genes, pathways and networks that control agricultural important traits. Because such advances will provide further details and complete understanding of interaction of plant systems and environmental variables, biotechnology is likely to be the most prominent part of the next generation of successful agricultural industry. In this article, we review the prospects for modification of agricultural target traits by genetic engineering, including enhancement of photosynthesis, abiotic stress tolerance, and pest and pathogen resistance associated with such pportunities and challenges under climate change.