• Bulletin of the Korean Chemical Society
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• 제24권8호
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• pp.1102-1106
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• 2003

In our previous work we developed the Finite Field method in order to calculate the fifth-order Raman response. The method was applied to calculate various polarization components of the two-dimensional response of liquid $CS_2$. So far, all calculations relied on the dipole-induced dipole. Accurate time-dependent density functional theory calculations have shown that this model has big discrepancies, when molecules are close together as in the liquid. We now report results of investigations on the importance of multipole and electron overlap effects on the polarizability and the fifth-order Raman response. It is shown that these collision effects, especially the induced multipoles, are crucial in the description of the fifth-order response. The impact is found to be especially pronounced for the χ_{mmzzzz}^{(5)}$response that is solely due to interaction induced effects. The calculated response will be compared with various experimental results.

• Tribology and Lubricants
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• 제26권5호
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• pp.272-276
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• 2010

Aminated oilve oil derivative as the new organic disperse phases of the water soluble metal working fluid has been synthesized and tribological properties of the aqueous solutions composed of aminated olive oil derivative investigated using Four Ball Wear Tester and Falex EP Tester. The formulated aqueous solutions showed higher antiwear and extreme pressure properties and also lower friction coefficient. On the basis of the the results, water soluble aminated oilve oil derivative showed excellent tribological properties due to the polarizability of oleic acid derivative composed of majority part in oilve oil.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.323-329
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• 2004

The electrical and rheological properties pertaining to the electrorheological (ER) behavior of chitosan derivatives, chitosan, chitosan ammonium salt and chitosan phosphate suspensions in silicone oil were investigated. Chitosan derivative suspensions showed a typical ER response (Bingham flow behavior) upon application of an electric field. However, chitosan phosphate suspension exhibited an excellent shear yield stress compared with chitosan and chitosan ammonium salt suspensions. The difference in behavior results from the difference in the conductivity of the disperse phases due to the difference of their polarizability. The shear stress for the chitosan, chitosan ammonium salt and chitosan phosphate suspensions exhibited a linear dependence on the volume fraction of particles and 1.18 ,1.41 and 1.67 powers of the electric field. On the basis of the experimental results, the newly synthesized chitosan derivative suspensions found to be an ER fluid.

• KSTLE International Journal
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• 제2권1호
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• pp.71-74
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• 2001

The electrorheological(ER) performance of a chitosan sebaciate suspension in silicone oil was investigated by varying the electric fields, volume fractions of particles, and shear rates, respectively. The chitosan sebacicate susepnsion showed a typical ER response caused by the polarizability of an amide polar group and shear yield stress due to the formation of multiple chains upon application of an electric field. The shear stress for the suspension exhibited a linear dependence on the volume fraction of particles and an electric field power of 1.88. On the basis of the results, the newly synthesized chitosan sebacicate suspension was found to be an anhydrous ER fluid.

• KSTLE International Journal
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• 제5권2호
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• pp.49-51
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• 2004

The electrical and rheological properties pertaining to the electrorheological (ER) behavior of chitosan derivatives, chitosan, chitosan ammonium salt and chitosan phosphated suspensions in silicone oil were investigated. Chitosan derivative suspensions showed a typical ER response (Bingham flow behavior) upon application of an electric field. However, chitosan phosphate suspension exhibited an excellent shear yield stress compared with chitosan and chitosan ammonium salt suspensions. The difference in behavior results from the difference in the conductivity of the disperse phases due to the difference of their polarizability. The shear stress for the chitosan, chitosan ammonium salt and chitosan phosphate suspensions exhibited a linear dependence on the volume fraction of particles and 1.18, 1.41 and 1.67 powers of the electric field. On athe basis of the experimental results, the newly synthesized chitosan dervative suspensions found to be an ER fluid.

• E2M - 전기 전자와 첨단 소재
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• 제9권3호
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• pp.265-269
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• 1996

We have studied the effect of the mesogenic core of nematic liquid crystals (NLCs) for polar (out-of-plane tilt) anchoring strength and surface order parameter on rubbed polyimide (PI) surfaces. The order of polar anchoring strength for NLCs on rubbed PI surfaces is 5CB > PCH5 > CCH5. From the above results, we suggest that the polar anchoring strength depends on the polarizability of the NLCs. The surface order parameter for NLCs is 5CB > PCH5 > CCH5 on rubbed PI surfaces. We conclude that the polar anchoring strength is strongly related to the surface order parameter on rubbed PI surfaces.

• 전자공학회논문지A
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• 제30A권2호
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• pp.29-35
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• 1993

A guided-wave TE to TM mode converter was demonstrated by using of the off-diagonal electrooptic coefficients in LiTaO$_{3}$. The input mode is coupled to the other orthogonal mode by the electrooptically induced off-diagonal polarizability. Compared with LiNbO$_{3}$, LiTaO$_{3}$ provides a smaller birefringence and thus a larger phase match period and larger optical bnadwidth. A novel electrode structure allowed a first-order Bragg-coupling phase matching. TE/TM mode conversion efficiency of 90% at 25 [V] was demonstrated with ${\lambda}$=0.63$\mu$m He-Ne laser.

• 대한화학회지
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• 제25권3호
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• pp.145-151
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• 1981

기체상에서의 이분자 친핵성치환반응에 대한, 고유한 반응성에 대하여 CNDO/2 방법의 분자궤도론적으로 논의 하였다. 친핵체 및 이탈기별로 반응물, 천이상태, 그리고 생성물에 대해 geometry optimization을 하고 구조와 형태를 고찰하였다. CNDO/2수준에서도 정성적인 논의가 가능하였으며 반응성은 친핵체의 염기도와 이로부터 유발된 분극력에 의해 지배되었다

• 대한화학회지
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• 제57권4호
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• pp.461-471
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• 2013

Optimized geometrical structure, atomic charges, molecular electrostatic potential, nonlinear optical (NLO) effects and thermodynamic properties of the title compound N-(2,5-methylphenyl)salicylaldimine (I) have been investigated by using ab initio quantum chemical computational studies. Calculated results showed that the enol form of (I) is more stable than keto form. The solvent effect was investigated for obtained molecular energies, hardneses and the atomic charge distributions of (I). Natural bond orbital and frontier molecular orbital analysis of the title compound were also performed. The total molecular dipole moment (${\mu}$), linear polarizability (${\alpha}$), and first-order hyperpolarizability (${\beta}$) were calculated by B3LYP method with 6-31G(d), 6-31+G(d,p), 6-31++G(d,p), 6-311+G(d) and 6-311++G(d,p) basis sets to investigate the NLO properties of the compound (I). The standard thermodynamic functions were obtained for the title compound with the temperature ranging from 200 to 450 K.

• KSTLE International Journal
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• 제3권1호
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• pp.23-25
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• 2002

The electrorheological (ER) behavior of amino coated chitosan phosphate suspension in silicone oil is investigated. Amino coated chitosan phosphate suspension shows a typical ER response (Bingham flow behavior) upon application of an electric field due to the polarizability of phosphoryl polar group. The shear stress for the suspension exhibits a linear dependence on an electric field power of 1.94. The values of structure factors $A_s$obtains 2 far mine coated chitosan phosphate suspension and it may be due to the formation of multiple chains upon application of the electric field. Throughtout the experimental results, amino coated chitosan phosphate suspension shows good dispersion stability and found to be an anhydrous ER fluid.