Amino - Carbonyl 反應에 미치는 溫度의 影響

김용년(Yong Nyun Kim),김창목(Chang Mok Kim),한강완(Kang Wan Han),오성기(Sung Ki Oh) 한국식품영양과학회 1982 한국식품영양과학회지 Vol.11 No.1

加工食品의 가장 重要한 色素形成으로 알려 진 非酵素的 褐變反應인 amino-carbonyl反應에 對한 溫度의 영향을 究明하기 위하여 0.05M glucose-arginine을 model system으로 선정하여 處理溫度 및 時間에 따라 分解되는 glucose 및 arginine의 含量變化와 生成되는 melanoidin 色素의 强度로써 反應速度常數와 半減期를 求하였으며, 또 Arrhenius 式에 따라 反應速度常數의 溫度依存性을 調査하였다.<br/> 1. 處理溫度 및 時間別로 分解되는 glucose 및 arginine의 定量은 carbohydrate analysis 및 μ Bondapak C_(18) column을 使用한 HPLC를 利用함이 效果的이었다.<br/> 2. glucose 및 arginine의 分解反應은 100℃ 및 120℃에서의 glucose를 제외하고는 모두 1次反應에 따랐으나, 100℃이상에서의 glucose에 있어서는 2相 1次反應(two-phase first-order reaction)에 따랐다. 또 melanoidin 生成反應에 있어서 60℃ 및 80℃에서는 1次反應에 따랐으나 100℃이상에서는 역시 2相1次反應에 따랐다.<br/> 3. glucose-arginine 反應에 의한 melanoidin 色素의 生成反應은 100℃ 및 120℃에서 3~5時間동안에 거의 완성단계에 있었으며 100℃이상에서는 거의 差가 없었다.<br/> 4. glucose 및 arginine의 分解反應과 melanoidin의 生成反應의 速度常數가 100℃ 및 120℃에서 현저한 增加現象을 나타내므로 amino-carbonyl 反應에 依한 褐色色素形成은 100℃이상의 고온에서 심하게 일어남을 알 수 있었다.<br/> 5. glucose 및 arginine의 分解反應과 이에 따른 melanoidin의 生成反應에 對한 反應速度常數의 溫度 依存性은 100℃이하에서는 Arrhenius式에 따랐으나 120℃이상의 高溫에서는 이에 따르지 않았다.<br/> 6. glucose 및 arginine 分解反應의 活性化에너지는 各各 12.512㎉/mole과 12.122㎉/mole로서 거의 비슷하고 melanoidin生成反應의 活性化에너지는 18.142㎉/mole로서 melanoidin生成反應이 溫度에 더 민감함을 보여주었다. The thermal degradation of 0.05M glucose-arginine model system was occurred during heat treatment for 0~7 hours at 60~120℃. and the melanoid in formation was investigated as a function of temperature. The decomposition reaction of glucose and arginine, as well as the reaction of melanoidin formation, followed first-order kinetics, except the reaction at 120℃. and the rate constants (hr^(-1) × 10³) of those reactions were ranged from 14.20 to 837. 10. Temperature dependence of the rate constants was characterized by the Arrhenius equation, except the reaction at 120℃. The ranges of activation energy and Q_(10) values were 12.122~18. 142 ㎉/mole and 1.65~2.12, respectively.

OSRVM의 형상 및 장착 위치에 따른 승용 차량의 공력성능 해석

한현욱(Hyun Wook Han),김지웅(Ji Woong Kim),김문상(Moon Sang Kim),하종백(Jong Paek Ha),김용년(Yong Nyun Kim) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11

This paper investigates the effects of OSRVM configurations such as mounting locations, housing heights, stalk heights, etc. on the aerodynamic performance of a passenger car. In the present paper, only one parameter, which is the mounting locations, is studied and presented. The other parameters will be studied in the near future. The OSRVM is mounted at the locations of -10㎜, -5㎜, 10㎜, 20㎜, 30㎜, 40㎜, and 50㎜ from the original location of the OSRVM. FLUENT, which is a very well-known commercial code, is used to analyze the aerodynamic performance of the passenger car.

CFD를 이용한 OSRVM 주위의 공력소음 해석

박현호(Hyun Ho Park),김지웅(Ji Woong Kim),김문상(Moon Sang Kim),하종백(Jong Paek Ha),김용년(Yong Nyun Kim) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11

The process of the wind noise analysis around OSRVM is constructed and is confirmed by simulating unsteady flow field past a generic side mirror mounted on the flat plate at the Reynolds number of R<SUP>e</SUP>D = 5.2×10? based on the mirror diameter. The transient flow field past a generic OSRVM is simulated with various turbulence models, namely DES and LES. The sound radiation is predicted using the Ffowkes-Williams and Hawkings analogy. For the present simulation, the 6.25 million cells are generated. Time averaged pressure coefficients at 34 locations on the surface of the generic OSRVM are compared with the available experimental data. Also, 12 Sound Pressure Levels located on the surrounding mirror are compared with the available experimental data. Both of them show good agreements with experimental data. Here, LES yields better solutions than DES.

차량 성능 개선을 위한 OSRVM의 최적 형상 연구

한현욱(Hyun Wook Han),박현호(Hyun Ho Park),김문상(Moon Sang Kim),하종백(Jong Paek Ha),김용년(Yong Nyun Kim) 한국자동차공학회 2011 한국자동차공학회 학술대회 및 전시회 Vol.2011 No.11

This study investigates the effects of OSRVM configurations such as bezel, stalk lengths, and head planview shape, etc. on the aerodynamic performance of the passenger car. In order to validate the flow solver, FLUENT which is a very well-known commercial code, the flow field around an Ahmed Body was analyzed numerically and compared with the experimental data. The predicted aerodynamic performance shows a good agreement with the experimental data. In the present paper, two parameters, which are the bezel and stalk length, are considered and presented. The other parameters will be studied in the near future.

OSRVM의 형상 매개변수에 따른 승용 차량의 공력성능 해석

한현욱(Hyun Wook Han),박현호(Hyun Ho Park),김문상(Moon Sang Kim),하종백(Jong Paek Ha),김용년(Yong Nyun Kim) 한국자동차공학회 2011 한국자동차공학회 부문종합 학술대회 Vol.2011 No.5

This study investigates the effects of OSRVM configurations such as mounting locations, housing heights, stalk heights, shrouding depths, stalk depths, and housing lengths, etc. on the aerodynamic performance of the passenger car. In order to validate the flow solver, FLUENT which is a very well-known commercial code, the flow field around an Ahmed body was analyzed numerically and compared with the experimental data. The predicted aerodynamic performance shows a good agreement with the experimental data. In the present paper, only three parameters, which are the mounting locations, stalk heights, and housing heights are studied and presented.

공력소음 해석절차 구축 및 OSRVM 외형변경에 따른 공력소음해석

박현호(Hyun Ho Park),한현욱(Hyun Wook Han),김문상(Moon Sang Kim),하종백(Jong Paek Ha),김용년(Yong Nyun Kim) 한국자동차공학회 2011 한국자동차공학회 부문종합 학술대회 Vol.2011 No.5

The transient flow field around an OSRVM is analyzed using the FLUENT and the sound radiation is predicted using the Ffowkes Williams and Hawkings analogy to analyze the wind noise around an OSRVM. Numerical results are compared with the available experimental data to validate the flow solver accuracy and the established analysis procedure. Five design key parameters of OSRVM, which are housing heights, stalk heights, shrouding depths, stalk depths, and housing lengths, are selected and parametric studies are performed numerically to figure out the effects of geometric shapes on the wind noise. In the present paper, however, only one parameter, which is the stalk heights, is studied and presented. The other parameters will be studied in the near future.

OSRVM의 형상 및 장착 위치가 차량의 공력성능에 미치는 영향

한현욱(Hyun Wook Han),박현호(Hyun Ho Park),김문상(Moon Sang Kim),하종백(Jong Paek Ha),김용년(Yong Nyun Kim) 한국자동차공학회 2013 한국 자동차공학회논문집 Vol.21 No.3

This study investigates the effects of OSRVM mounting location and its configurations such as stalk height and housing height on the aerodynamic performance of the passenger car. In order to validate the flow solver, FLUENT which is very well known commercial code, the flow field around an Ahmed Body was analyzed numerically and compared with the experimental data. The predicted aerodynamic performance and flow patterns around a car show good agreements with the experimental data. Mounting location and stalk height should be designed while OSRVM is mounted on the car to evaluate the aerodynamic performance precisely. Housing height, however, may be designed independent of the car because the aerodynamic interference between housing height and car configuration is negligible.

AUSM 풍상차분법을 이용한 고속 점성 유동장 해석에서 최적의 수치적 벽면 경계조건 도출에 관한 연구

김용년,전병우,김문상 한국 항공대학교 항공산업기술연구소 2001 航空宇宙産業技術硏究所 硏究誌 Vol.11 No.-

Navier-Stokes 방정식을 사용하여 점성 유동장을 해석할 때 해의 정확도 및 수렴성에 영향을 줄 수 있는 요인들에는 여러 가지가 있다. 그 중에서도 물체 벽면에 부과되는 벽면 경계조건은 가장 큰 요인들 중에 하나로서, 본 논문에서는 단열 조건 혹은 주어진 벽면 온도 조건 하에서 추가적으로 요구되는 여러 종류의 수치적 벽면 경계조건들에 대해서 고속으로 비행하는 1/4 원형 실린더 주위 및 20도의 쐐기 형상을 갖는 물체 주위의 유동장을 해석해 봄으로써 가장 바람직한 해석 결과를 보여주는 벽면 경계조건을 도출하였다. 본 연구를 위해서 유한체적법을 사용한 2차원 Navier-Stokes 프로그램을 개발하였으며 대류항은 AUSM 풍상차분법을, 확산항은 중심차분법을 사용하여 플럭스를 계산하였다. There are many factors to affect the numerical solution accuracy and stability in viscous flowfields analysis using the Navier-Stokes equations. Wall boundary condition imposed on the solid wall is one of the most important factors. In this paper, several different sets of numerical wall boundary conditions are investigated to figure out what is the most optimum numerical wall boundary condition set by analyzing the flowfields around a 1/4 circular cylinder and 20 degree wedge shape geometry in very high speed flow under adiabatic or fixed wall temperature condition. The optimum wall boundary condition is introduced by simulating a finite volume Navier-Stokes solver, which hires AUSM upwind scheme to calculate the convection fluxes and central scheme to calculate the diffusion fluxes.

Boileau의 "l'Art poetique " 일고

김용년 한국불어불문학회 1984 佛語佛文學硏究 Vol.19 No.1

Boileau-Despre´aux e´tait fils d'un modeste commis au greffe du parlement, mais fit de bonnes e´tudes au colle`ge d'Harcourt et fut entrai^ne´ vers les belles-lettres par son fre`re. Il a e´crit ses Satires. Il devient historiographe du roi avec Racine. Racine mort, il s'efface de la cour et du monde. Puis il s'engage de plus en plus dans la querelle du janse´nisme. En 1705 ou 1706, il commence a` e´crire un long poe`me contre la Compagnie de Je´sus. Il s'e´tait assure´ l'approbation du chancelier et du cardinal, mais tous les efforts tente´s pour obtenir l'autorisation de parai^tre e´choue`rent. En 1710, Louis XIV fit savoir son refus absolu et de´finitif. Le vieux poe`te, de´sespe´re´, mourut en 1711, le dernier de sa ge´ne´ration. Boileau a e´crit son Art poe`tique et a donne´ a` l'expose´ de Pisons un tour doctrinal qui risque de faire illusion. Il est simplement le porte-parole et cherche a` faire connai^tre aux gens du monde, d'apre`s les oeuvres, les principes de la composition litte´raire. L' Art poe`tique comprend quatre chants. Le Chant I renferme des pre´ceptes ge´ne´raux, . Le Chant IV est moral. Le Chant II est consacre´ aux genres secondaires: idylle, e´le´gie, ode, sonnet, e´pigramme, rondeau et ballade, madrigal, satire, vaudeville. Le Chant III est consacre´ aux grands genres, que Boileau pre´sente dans un ordre assez singulier: la Trage´die, l'Epique, la Come´die. On peut y trouver trois importants e´le´ments:l'e´le´ment de l'histoire litte´raire, l'e´le´ment critique de la litte´rature, l'e´le´ment pole´mique. L' Art poe`tique est un excellent expose´ des ide´es des grands e´crivains classiques de la France. Le vice de Boileau est le manque de sens historique: ainsi s'expliquent la plupart des omissions et des erreurs de Boileau, et surtout ce dogmatisme excessif qui me´connai^t la diversite´ des pays et des e´poques et rame`ne tous les genres a` l'ide´e souvent e´troite que s'en faisait l'auteur.