'지도사 사업영역 (事業領域) 확대를 위한 제언'

최영상,Choe, Yeong-Sang 한국경영기술컨설턴트협회 2004 컨설턴트 Vol.21 No.-

응축충격파와 경계층 간섭의 피동제어(I)

최영상,정영준,권순범,Choe, Yeong-Sang,Jeong, Yeong-Jun,Gwon, Sun-Beom 대한기계학회 1997 大韓機械學會論文集B Vol.21 No.2

There were appreciable progresses on the study of shock wave / boundary layer interaction control in the transonic flow without nonequilibrium condensation. But in general, the actual flows associated with those of the airfoil of high speed flight body, the cascade of steam turbine and so on accompany the nonequilibrium condensation, and under a certain circumstance condensation shock wave occurs. Condensation shock wave / boundary layer interaction control is quite different from that of case without condensation, because the droplets generated by the result of nonequilibrium condensation may clog the holes of the porous wall for passive control and the flow interaction mechanism between the droplets and the porous system is concerned in the flow with nonequilibrium condensation. In these connections, it is necessary to study the condensation shock wave / boundary layer interaction control by passive cavity in the flow accompanying nonequilibrium condensation with condensation shock wave. In the present study, experiments were made on a roof mounted half circular arc in an indraft type supersonic wind tunnel to evaluate the effects of the porosity, the porous wall area and the depth of cavity on the pressure distribution around condensation shock wave. It was found that the porosity of 12% which was larger than the case of without nonequilibrium condensation produced the largest reduction of pressure fluctuations in the vicinity of condensation shock wave. The results also showed that wider porous area, deeper cavity for the same porosity of 12% are more favourable "passive" effect than the cases of its opposite. opposite.

다공벽을 이용한 충격파 강도의 피동제어

최영상,권순범,조철영,Choe, Yeong-Sang,Gwon, Sun-Beom,Jo, Cheol-Yeong 대한기계학회 1997 大韓機械學會論文集B Vol.21 No.1

A shock wave, being an irreversible process, gives rise to entropy increase. A great deal of effort has been made to control shock wave and boundary layer interaction related to energy losses as well as problems of vibration and noise. In the present study, tests are performed on a roof mounted half circular arc in an indraft type supersonic wind tunnel to evaluate the effects of porosity, length and depth of cavity in passive control of shock wave on the attenuation of shock strength by reviewing the measured static pressures at the porous wall and cavity. Also the flow field is visualized by a Schlieren system. The results show that in the present study the porosity of 8% produced the largest reduction of pressure fluctuations and that for the same porosity, the strength of shock wave decreases with the increasings of the depth and length of cavity.

건축물 화재 시 재해약자를 고려한 피난계획 중요도 분석

이호영(Lee, Ho-Yeong),최영상(Choe, Yeong-Sang),최영오(Choe, Yeong-O),최재원(Choe, Jae-Won),홍원화(Hong, Won-Hwa) 한국화재소방학회 2013 한국화재소방학회 학술대회 논문집 Vol.2013 No.춘계

지금까지의 피난계획이 피난 시 가장 취약한 재해약자에 대한 고려가 미흡하여 이들을 고려한 피난계획의 방향을 제시하고자 하며, 건축물 화재 시 재해약자들의 피난안전성 확보를 위해 기존문헌들을 통해 피난계획 항목 및 요소를 조사하고, 건축 소방분야 전문가들을 대상으로 예비 조사 및 본 조사를 실시한 후 통계분석 프로그램을 사용하여 기술통계, 중요도분석, 상관분석을 통해 피난계획의 항목 및 세부요소의 중요정도를 알아보고자 한다.

고온에서 근적외선 분광법을 이용한 사염화탄소내에서의 Thioacetamide와 N,N-dimethylacetamide사이의 수소결합에 관한 연구

김지영,최영상,김건,Kim, Ji Yeong,Choe, Yeong Sang,Kim, Geon 대한화학회 1990 대한화학회지 Vol.34 No.6

아세트아미드의 아미노 양성자의 화학적 이동과 N-C(O) 결합주위의 부자유회전에 미치는 n-알코올 용매 효과

권순기,최종호,최영상,윤창주,권대근,Gwon, Sun Gi,Choe, Jong Ho,Choe, Yeong Sang,Yun, Chang Ju,Gwon, Dae Geun 대한화학회 1990 대한화학회지 Vol.34 No.6

n-알코올 용매에서 아세트아미드(AA)의 아미노 양성자의 nmr 화학적 이동과 선모양을 온도의 함수로 조사 연구하였다. 아미노 양성자의 화학적 이동 변화를 용매의 극성 파라미터 중에서 Reichardt의 $E_{T}$(30)으로 고찰하여 그들 사이에 다음과 같은 관계가 존재함을 밝혔다. ${\delta}_{obs}$ = ${\delta}_{o}$ + aE$_{T} (30) + b[E_{T}(30)]^2$ 여기서 ${\delta}_{o}$는 용질의 기체 상태 또는 $E_{T}$(30)가 0인 상태에서의 용질의 화학적 이동이며, a는 알코올 용액에서 용질이 갖는 고유한 특성이며, b는 용질-용매의 상호작용을 나타내는 상수이다. 또한, 선모양의 분석에서 얻은 N-C(O) 결합 주위로의 부자유회전 장애도 아미노 양성자에 대한 화학적 이동의 행동과 유사하게 용매의 $E_{T}$(30)과 밀접한 관계가 있음을 알아 내었다. 1H-nmr chemical shifts and lineshapes of amino-protons of acetamide (AA) in n-alcohols were determined. The chemical shifts are discussed by the Reichardt's solvent polarity parameter, E$_{T}$(30). The following relationship between $\delta$obs and E$_{T}$(30) was obtained. ${\delta}_{obs}$ = ${\delta}_{o}$ + aE$_{T}$ (30) + b[E$_{T}$(30)]$^2$ where ${\delta}_{o}$ is the chemical shift of the solute in gaseous state or at $E_{T}$(30) = 0, a is a characteristic constant for the protons of AA in n-alcohol solutions and b is a constant for the solute (AA)-solvent (n-alcohols) interaction. The barrier of the hindered rotation about the N-C(O) bond in AA was obtained by analysis of the lineshapes of the amino-protons in AA. The behavior of the internal rotation as well as chemical shifts of the amino-protons in AA has been found to be closely related to the $E_{T}$(30) of n-alcohols.

아조벤젠 유도체의 이성질화 반응속도에 관한 연구

양시영,김종규,허영덕,최영상,Yang, Si Yeong,Kim, Jong Gyu,Heo, Yeong Deok,Choe, Yeong Sang 대한화학회 1994 대한화학회지 Vol.38 No.8

아조벤젠 유도체의 시스→트란스 열적 이성질화 반응을 연구하였다. 밀고-당기는 아조벤젠은 이성질화 반응속도의 용매효과가 큼이 확인되었고 이러한 현상으로 밀고-당기는 아조벤젠은 회전 메카니즘에 의해서 이성질화 반응이 일어남을 알 수 있다. 밀고-당기는 아조벤젠이 아닌 화합물은 이성질화 반응속도의 용매효과가 거의 없음이 관찰되었으므로 반전 메카니즘에 의해서 이성질화 반응이 일어남을 확인하였다. The cis → trans thermal isomerization of azobenzene derivatives has been studied. A sizable solvent effect on the rates for thermal isomerization of push-pull azobenzenes are observed. It is suggested that the isomerization proceeds via a rotational mechanism. For non push-pull azobenzenes, the lack of solvent effects on the rate of isomerization was observed. This suggests that the isomerization proceeds via an inversional mechanism for non push-pull azobenzenes.

Thioacetamide 와 피리딘계 헤테로고리 화합물 사이의 수소 결합에 대한 연구

박재헌,이미경,오인철,윤창주,최영상,Park, Jae Heon,Lee, Mi Gyeong,O, In Cheol,Yun, Chang Ju,Choe, Yeong Sang 대한화학회 1994 대한화학회지 Vol.38 No.5

클로로포름과 사염화탄소 속에서 티오아세트아미드(TA)와 pyridine(Py), quinoline(Qu), and acridine(Ac)간의 수소 결합에 대한 열역학적 상수들을 조사하기 위해 5$^{\circ}C$ 에서 55$^{\circ}C$까지 TA의 $v_{a^+}$ Amide II조합띠를 사용하였다. 이 조합띠는 두 개의 Lorentzian-Gauss 곱함수의 띠로 분해되며, 각각은 TA단위체 및 수소결합을 이룬 TA의 복합체임이 확인되었다. 온도 및 농도에 따른 이 조합띠의 변화로부터 TA의 수소 결합에 대한 여러가지 열역학적 상수들을 구하였다. 클로로포름에서 TA 와 pyridine, quinoline, acridine의 수소결합 엔탈피는 각각 -7.6 kJ/mol, -6.5 kJ/mol, -5.4 kJ/mol이었고, 사염화탄소에서 TA 와 pyridine, quinoline의 결합 엔탈피는 각각 -13.3kJ/mol, -12.0kJ/mol이었다. The $v_{a^+}$ Amide II combination band of thioacetamide has been used to evaluate thermodynamic parameters of the hydrogen bonding of thioacetamide(TA) with pyridine(Py), quinoline(Qu), and acridine(Ac) in $CHCl_3$ and $CCl_4$ over the temperature range from 5$^{\circ}C$ to 55$^{\circ}C$. This combination band was resolved into two Lorentzian-Gaussian product bands which have been identified withmonomeric TA and hydrogen bonded TA. The thermodynamic parameters for the hydrogen bonded TA were determined by computer analysis of concentration and temperature dependent spectra. The standard enthalpies for the 1 : 1 hydrogen bonded complex of TA to pyridine, quinoline, and acridine in $CHCl_3$ have been found to be -7.6 kJ/mol, -6.5 kJ/mol, and -5.4 kJ/mol, respectively. And the standard enthalpies for the 1: 1 hydrogen bonded complex of TA to pyridine and quinoline in $CCl_4$ have been found to be -13.3kJ/mol, and -12.0kJ/mol, respectively.

The Study of the Solvent Effect on the Quadruple Relaxation Rate of ¹⁴N in Thioacetamide

Kim, Young-Jun,Choe, Yoon-Kee,Choi, Young-Sang,Yoon, Chang-Ju 가톨릭대학교 자연과학연구소 1998 자연과학논문집 Vol.19 No.-

The ¹H-NMR spectra of amino group in thioacetamide(TA) are observed to be a triplet of double triplet in some solvents such as acetonitrile, nitromethane, 1,4-dioxane, DMSO and water. The triple was resulted from scalar coupling to nitrogen nucleus of amino protons and the double triplet was observed from the two amino protons having slightly different chemical shifts. New model for the double triplet was proposed from the results. From the lineshape analysis, it is possible to obtain the spin-lattice relaxation rate of nitrogen nucleus ((1/T₁)_(N)), in TA and the differences in chemical shifts of two amino protons. They are obtained in various solvents over the temperature range from their m.p. to b.p. The solvent effects on chemical shifts are discussed in terms of solvent polarity. The correlation time, τ_(c), which is related to (1/T₁)_(N), are discussed on the basis of hydrodynamic friction model and compared with solvent dielectric relaxation time(τ_(D), τ₁).