• 대한기계학회논문집B
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• 제24권12호
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• pp.1644-1651
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• 2000

In this study, the confined laminar flow and transport around a square cylinder with a planar fuel jet are numerically simulated. Both rear and front jets are considered, respectively. In each case, various ratios of the jet velocity to the fixed upstream velocity are taken into consideration. In case of the rear jet, the high mass-fraction region is formed along the streamlines from the jet exit, and the oscillation of the force on the square cylinder eventually disappears as the jet velocity is close to the upstream velocity. In case of the front jet, drag is significantly reduced when the jet velocity ratio is grater than 1. The results obtained exhibit flow and scalar-mixing charactered in a planar combustor.

• Bulletin of the Korean Chemical Society
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• 제2권3호
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• pp.79-82
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• 1981

A calculation method of the dipole moments for square planar and tetrahedral complexes by the valence bond method has been developed and an example calculation was carried out choosing the square planar and tetrahedral $[M(Ⅱ)N_2Se_2]$ type complexes. The calculated values of the dipole moments by the valence bond method are higher than those of the approximate orbital method. We found that we may predict the geometric structure of the transition metal complexes comparing the calculated values of the dipole moments with the experimental values. A new method for definition of C' parameter has also developed on the basis of extended Huckel theory.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1994년도 추계학술대회 논문집
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• pp.44-54
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• 1994

A variational formulation and the associated finite elemet equations have been derived for general three-dimensional deformation of a planar anisotropic rigid-plastic sheet metal which obeys the strain-rate potential proposed by BARLAT et al [13]. By using the natural convected coordinate system, the effect of geometric change and the rotation of planar anisotropic axes are considered efficiently. In order to check the validity of present formulation, a cylindrical cup and a square cup deep drawing test was modeled. good agreement was found between the FE simulation and the experiment. The results have shown that the present formulation for planar anisotropic deformation can be efficiently applied to the analysis of sheet metal working processes for planar anisotropic nonferrous metals.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.759-764
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• 2000

In this study, the confined laminar flow around a square cylinder, which ejects a either on the front face or on the rear face, is numerically simulated. In each case, three ratios of jet velocity to the fixed upstream velocity are considered. In all cases of the rear fuel jet, the high mass-fraction region is formed along the streamlines from the jet exit. In case of front jet, drag is significantly decreased when the jet velocity ratio is greater than 1. The results obtained exhibit flow and scalar-mixing characteristics encountered in a planar combustor

• 대한화학회지
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• 제26권5호
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• pp.265-273
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• 1982

두다른 방법을 사용하여 사면체 및 사각형[M(Ⅱ)$O_2S_2$] 형태 착물의 쌍극자모멘트에 대한 ${\pi}$결합의 영향을 고찰하였다. 그첫째 방법은 금속이온의 원자가 궤도함수와 리간드 궤도함수 사이의 혼성계수 CM이 ${\sigma}$ 및 ${\pi}$결합 분자궤도함수에 대하여 모두 같다는 가정에 기초를 둔 근사 분자궤도함수 법이며 다른 하나는 반경험적인 LCAO-MO법에 기초를 둔 계산이다. ${\sigma}$ 결합만이 형성되었다고 가정한다면 사면체 및 사각형 착물의 계산한 쌍극자 모멘트는 실험치 보다 작다. 계산한 쌍극자 모멘트에 ${\pi}$결합의 기여분을 모두 고려 해 준다면 사각형 및 사면체 $[M (II)O_2S_2]$형태 착물의 계산한 쌍극자모멘트는 실험치보다 크다. 그러나 ${\pi}$결합이 비편재 되었다고 가정한다면 사면체 [M(II)$O_2S_2$]형태 착물의 계산한 쌍극자 모멘트가 실험치 범위안에 들지만 사각형착물의 쌍극자 모멘트는 실험치에서 벗어난다. 이 결과는 [M(II)$O_2S_2$]]형태 착물이 비극성 용매의 용액에서 사면체 구조로 존재함을 암시하며 이 구조는 실험구조와 일치한다. 사면체 [M(II)$O_2S_2$] 형태착물의 계산한 쌍극자모멘트는 쌍극자모멘트에 ${\pi}$결합이 참여함을 지적한다.

• 한국결정학회:학술대회논문집
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• 한국결정학회 2001년도 정기총회 및 춘계학술대회연구발표회(한국결정학회)
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• pp.20-20
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• 2001

• Bulletin of the Korean Chemical Society
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• 제27권3호
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• pp.386-388
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• 2006

Membrane proteins in highly oriented lipid bilayer samples are useful for membrane protein structure determination. We used in the past planar lipid bilayers which were aligned and supported on the glass slide. These samples were mechanically aligned in a magnetic field. However, these stacks of glass slides with planar lipid bilayers are not well suited for use with a commercial solid-state NMR probe with a round coil. Therefore, a homebuilt solid-state NMR probe was built and used with a stack of thin glass plates wherein the RF coil was wrapped directly around the flat square sample. Recently, we began to use magnetically aligned bicelles that are suitable for the structure determination of membrane proteins by solid-state NMR spectroscopy without any effort to build a flat square coil probe. These bicelle samples are well suited for use with a commercial solidstate NMR probe with a round coil, are very easy to prepare and are very stable, so that they can be kept for more than a year. In this paper, we present the solid-state NMR spectra of optimized and magnetically oriented bicelle samples of membrane proteins.

• 한국전기전자재료학회논문지
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• 제17권12호
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• pp.1314-1319
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• 2004

The rosen types of piezo-transformers were prepared and electrical properties were investigated in order to establish the optimum parameters in the process of polarization for ferroelectric materials. Polarization was readily originated with increasing the external energy such as an applied voltage, time, and temperature so that the planar coupling factor and voltage gain were saturated under the conditions of over 14$0^{\circ}C$, applied voltage and time of 4 kV/mm and 3 minutes respectively. The empirical equation for domain rotation probability, which was in proportion to square of an applied voltage and temperature and square root of time, as functions of the above parameters was defined.

• Mycobiology
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• 제34권4호
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• pp.214-218
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• 2006

Four copper(II) complexes have been prepared using macrocyclic ligands. The macrocyclic ligands have been synthesized by the condensation reaction of diethyl phthalate with Schiff bases derived from o-phenylene diamine and Knoevenagel condensed ${\beta}-ketoanilides$ (obtained by the condensation of acetoacetanilide and substituted benzaldehydes). The ligands and copper complexes have been characterized on the basis of Microanalytical, Mass, UV-Vis., IR and CV spectral studies, as well as conductivity data. On the basis of spectral studies, a square-planar geometry for the copper complexes has been proposed. The in vitro antifungal activities of the compounds were tested against fungi such as Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans. All the synthesized copper complexes showed stronger antifungal activities than free ligands. The minimum inhibitory concentrations (MIC) of the copper complexes were found in the range of $8{\sim}28\;{\mu}g/ml$. These compounds represent a novel class of metal-based antifungal agents which provide opportunities for a large number of synthetic variations for modulation of the activities.

• Bulletin of the Korean Chemical Society
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• 제25권12호
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• pp.1757-1763
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• 2004

A new series of nickel(II), cobalt(II)/(III) and copper(II) complexes of 14, 15 and 16-membered of macrocyclic ligands have been prepared and characterized by elemental analyses, IR, UV-VIS and $^1H-NMR$ spectra, magnetic susceptibilities, conductivities, DTA and ESR measurements. Molar conductances in DMF solution indicate that, the complexes are nonelectrolytes except (9-12) complexes. The electronic spectra show that, all complexes are square planar or distorted octahedral geometry. The ESR spectra of solid complexes (4), (8) and (11) show square planar of axial type symmetry $(d_{x2-y2})$ with considerable covalent bond character. However, complex (12) shows a spectrum of octahedral geometry with $d_{z2}$ ground state. Complex (12) shows exploitation in reducing the amount of electron adducts formed in DNA during irradiation with low radiation products.