• Elastomers and Composites
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• v.30 no.2
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• pp.105-111
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• 1995

The thermal decomposition of the paper sludge with poly (acrylonitrile-butadiene-styrene) was using a thermal analysis techniques in the stream of nitrogen gas of 30ml/min at various heating rates from 4 to $20^{\circ}C/min$. The mathmatical, derivative and integral method were used to obtain values of activation energy of decomposition reaction. 1. The values of activation energy evaluated by derivative and Intergral method were consistent with each other very well. 2. The maximum value of heat of decomposition evaluated by DSC method was 10.120cal/g at weight ratio of paper sludge/ABS=20/80. 3. The thermogravimetric trace curve agreed with the theoretical equation.

• Elastomers and Composites
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• v.31 no.2
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• pp.122-129
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• 1996

The Thermal decomposition of the ${\alpha}-Cellulose$ and NaCl was studied using a thermal analysis technique in the steam of nitrogen gas with 30ml/min at various heating ranges from 4 to $20^{\circ}C/min$. The Derivative and Integral method used to be obtained values of activation energy of decomposition reaction. 1. The values of activation energy evaluated by Derivative and Intergral method were consistent with each other very well. 2. The maximum value of heat of decomposition evalated by DSC method was ${\alpha}-Cellulose/NaCl= 90/10$. 3. The thermogravimetric trace curve agreed with the theoretical equation.

• 전기의세계
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• v.14 no.2
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• pp.14-24
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• 1965

The characteristics of servo-multipliers and its accuracies are analyzed. From the analysis a low cost high accuracy four quadrant servo-multiplier with first derivative output feedback is built. The multiplier servomechanism has a second order system response with a damping ratio of 0.8 and computing bandwidth of 4 cycles per second, and its tracking accuracy at low speed of 0.5 volt per second is 0.9 per cent of maximum output voltage and static accuracy is better than 0.6 per cent. Method of testing this multiplier and the results are also described. The test on the characteristics of the multiplier shows that the results agree with theoretical values satisfactorily, and justifies the use of the servo-multiplier for slow type analog computers.

• Journal of applied mathematics & informatics
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• v.28 no.5_6
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• pp.1035-1054
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• 2010

We consider a mixed type singularly perturbed one dimensional elliptic problem with discontinuous source term. The domain under consideration is partitioned into two subdomains. A convection-diffusion and a reaction-diffusion type equations are posed on the first and second subdomains respectively. Two hybrid difference schemes on Shishkin mesh are constructed and we prove that the schemes are almost second order convergence in the maximum norm independent of the diffusion parameter. Error bounds for the numerical solution and its numerical derivative are established. Numerical results are presented which support the theoretical results.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.1
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• pp.171-179
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• 2001

The purpose of this paper is the derivation and development of the new definitions and methods for the new estimation of robustness for the systems having structured uncertainties. This proposition adopts the theoretical analysis of the Lyapunov direct methods, that is, the sign properties of the Lyapunov function derivative integrated along finite intervals of time, in place of the original method of the sign properties of the time derivative of the Lyapunov function itself. This is the new sufficient criteria to relax the stability condition and is used to generate techniques for the robust design of control systems with structured perturbations. The systems considered are assumed to be nominally linear, with time-variant, nonlinear bounded perturbations. This new techniques demonstrate the improvement of robustness bounds from the numerical results.

• Kyungpook Mathematical Journal
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• v.62 no.3
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• pp.583-593
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• 2022

Lienard's equations are important nonlinear differential equations with application in many areas of applied mathematics. In the present article, a new approach known as the modified fractional Taylor series method (MFTSM) is proposed to solve the nonlinear fractional Lienard equations with Caputo fractional derivatives, and the convergence of this method is established. Numerical examples are given to verify our theoretical results and to illustrate the accuracy and effectiveness of the method. The results obtained show the reliability and efficiency of the MFTSM, suggesting that it can be used to solve other types of nonlinear fractional differential equations that arise in modeling different physical problems.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1667-1670
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• 2009

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.770-774
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• 2014

The bond dissociation energy (BDE) of the chemical bond between the carbon and oxygen atoms of a simple TEMPO-derivative is calculated by employing the density functional theory, the $2^{nd}$ order M${\phi}$ller-Plesset (MP2) perturbation theory, and complete basis set (CBS) methods. We find that BDE of the positive ion of the TEMPO-derivative is larger at least by 7 kcal/mol than that of the negative ion, which implies that the dissociation reaction rate of the positive ion should be slower than that of the negative ion. Such theoretical predictions are contrary to the results of our previous experiments (Anal. Chem. 2013, 85, 7044), in which the larger energy was required for negative o-TEMPO-Bz-C(O)-peptides to undergo the dissociation reactions than for the positive ones. By comparing our theoretical results to those of the experiments, we conclude that the dissociation reaction of o-TEMPO-Bz-C(O)-peptide should occur in a complicated fashion with a charge, either positive or negative, probably being located on the amino acid residues of the peptide.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1875-1880
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• 2010

A dicycle pyrazoline derivative, 1-phenyl-5-(p-fluorophenyl)-3,4-($\alpha$-p-fluoro-tolylenecyclohexano) pyrazoline, was synthesized and characterized by elemental analysis, IR, UV-vis, fluorescence spectra and X-ray single crystal diffraction. Density function theory (DFT) calculations were performed by using B3LYP method with 6-$311G^{**}$ basis set. The optimized geometry can well simulate the molecular structure. Vibrational frequencies were predicted, assigned and compared with the experimental values, which suggest that B3LYP/6-$311G^{**}$ method can well predict the IR spectra. Both the experimental electronic absorption spectra and the predicted ones by B3LYP/6-$311G^{**}$ method reveal three electron-transition bands, with the theoretical ones having some red shifts compared with the experimental data. Natural bond orbital analyses indicate that the absorption bands are mainly derived from the contribution of n $\rightarrow\pi^*$ and $\pi\rightarrow\pi^*$ transitions. Fluorescence spectra determination shows that the title compound can emit blue-light at about 478 nm. On the basis of vibrational analysis, the thermodynamic properties of title compound at different temperature have been calculated, revealing the correlations between $C^0_{p,m}$, $S^0_m$, $H^0_m$ and temperature.

• Applied Microscopy
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• v.39 no.2
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• pp.175-183
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• 2009

In this paper we present sub-50 pm resolution images of atom columns simulated with the negative of the second derivative of the exit-plane wave function (EPW). The EPW can be retrieved from a focal series reconstruction in the (high resolution) transmission electron microscopy (HRTEM). The simulated images are for Si and InAs in [114] and [116] orientations, which give about sub-50 pm separations of atom columns. The theoretical reason for the validity of this method is given from analysis based on the kinematical diffraction theory, and the limitation for applicability of this method also is discussed.