• YAKHAK HOEJI
• /
• v.35 no.1
• /
• pp.1-6
• /
• 1991

Fast Hartley transform(FHT) was used for the identification of derivative UV spectra of pharmaceuticals, with the advantages of relatively shorter computing time of FHT and more precise results. The arccosine value of dot product of two vectors of normalized FHT coefficients calculated from two compared derivative spectra was a reasonable parameter for the spectral identification. Using this parameter, the similar patterns of derivative spectra of 13 penicillins can be differenciated from each other. The concentration difference and the minor contamination did not interfere the results of identification procedures. All these procedures of identification were accomplished successfully by the computer program, [SPECMAN PLUS] version 1.30, which was developed for this article.

• Archives of Pharmacal Research
• /
• v.12 no.4
• /
• pp.289-294
• /
• 1989

A computer program which can differentiate compounds whose absorbance spectra are very similar was developed. The program. [SPECMAN PLUS], written in Pascal provides automated spectral comparison techniques, utilizing the values of Root Mean of Squares (RMS) of differences. This comparison routine of the program can deal with spectra of compounds different concentrations and different spectral recording resolutions. In addition, the program was designed applicable to any spectral data of digital form. The program was applied to the UV spectra of 13 pencillins and 5 cephalosporins, whose absorbance spectra are so similar. As a result, all compounds examined could be differentiated from each other.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.53 no.3
• /
• pp.314-319
• /
• 2008

Near infrared (NIR) spectroscopy was used to classify normal and artificially aged nonviable corn (Zea mays L., cv. 'Suwon19') seeds. The spectra at 1100-2500nm were scanned with normal and artificially aged single seeds and analyzed by principle component analysis (PCA). To discriminate normal seeds from artificially aged seeds, a calibration modeling set was developed with a discriminant partial least square 2 (PLS 2) method. The calibration model derived from PLS 2 resulted in 100% classification accuracy of normal and artificially aged (aged) seeds from the raw, the 1st and 2nd derivative spectra. The prediction accuracy of the unknown normal seeds was 88, 100 and 97% from the raw, the $1^{st}$ and $2^{nd}$ derivative spectra, and that of the unknown aged seeds was 100% from all the raw, the $1^{st}$ and $2^{nd}$ derivative spectra, respectively. The results showed a possibility to separate corn seeds into viable and non-viable using NIR spectroscopy.

• YAKHAK HOEJI
• /
• v.30 no.2
• /
• pp.100-103
• /
• 1986

The second derivative absorption spectra of acetaminophen in commercial tablet forms were measured without prior separation from other pharmaceutical adjuvants. The second derivative spectra of acetaminophen were found to have no influence on the characteristic absorbance band of it. A plot of 25 sets of the ordinate (Z) values with various acetaminophen concentrations mixed in other additives gave a straight line (correlation coefficient, 0.9999) and the slope was 2.901${\times}10^{-2}Z$ value/($\mu\textrm{g}$/ml). The procedures were sufficiently sensitive, precise and economical for the assay of tablets of acetaminophen.

• Bulletin of the Korean Chemical Society
• /
• v.9 no.2
• /
• pp.84-87
• /
• 1988

The Photophysical and photochemical properties of Ruthenium bipyridine with two long hydrocarbon chains, $[Ru(bipy)_2(dhbipy)]^{2+}$ and transient phenothiazine derivative cation radical $(PTD^+)$ in the cationic vesicle were studied. Transient absorption spectra of cation radical of phenothiazine derivative in the vesicle system containing the $Ru^{2+}$ complex, $[Ru(bipy)_2(dhbipy)]^{2+}$, (1) as sensitizer and phenothiazine derivative as electron donor was observed by XeCl excimer laser photolysis system. Thus the excited ruthenium complex would be quenched by phenothiazine derivative(PTD) reductively in the vesicle system. The quenching rate constant($K_Q$) of $Ru^{2+}$ with two long hydrocarbon chains in the vesicle by PTD was $9.6{\times}10^8M^{-1}S^{-1}$. The absorption decay kinetics showed that lifetime of phenothiazine derivative cation radical is a value in the 4-8m sec range.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.11 no.10
• /
• pp.778-783
• /
• 1998

Film characteristics of thin ONO dielectric layers for MONOS(metal-oxide-nitride-oxide-semiconductor) EEPROM was investigated by TEM, AES and AFM. Seocnd derivative spectra of Auger Si LVV overlapping peak provide useful information fot chemical state analysis of superthin film. The ONO film with dimension of tunnel oxide 23$\AA$, nitride 33$\AA$, and blocking oxide 40$\AA$ was fabricated. During deposition of the LPCVD nitride film on tunnel oxide, this thin oxide was nitrized. When the blocking oxide was deposited on the nitride film, the oxygen not only oxidized the nitride surface, but diffused through the nitride. The results of ONO film analysis exhibits that it is made up of $SiO_2$ (blocking oxide)/O-rich SiON(interface)/N-rich SiON(nitride)/ O-rich SiON(tunnel oxide)

• Archives of Pharmacal Research
• /
• v.10 no.1
• /
• pp.1-8
• /
• 1987

One of the problems of derivatie spectrophotometry, the decrease of signal-to-noise ratio by derivative operations, was solved by three concepts of digital filtering, ensemble averaging, least squares polynomial smoothing and Fourier smoothing. The suthors made several compouter programs written in APPLE SOFT BASIC language for the actual applications of the concepts of these digital filters on UV spectrophotometer system. As a result, ensemble averaging could not be used as a routine operation for the spectrophotometer used. The maximum S/N ratio enhancement factors achieved by least squares polynomial smoothing were 6.17 and 7.47 for the spectra of Gaussian and Lorentzian distribution models, and by Fourier smoothing 16.42 and 11.78 for the spectra of two models, respectively.

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

• Journal of the Korean Wood Science and Technology
• /
• v.47 no.1
• /
• pp.101-109
• /
• 2019

This paper examines the classification of five coniferous species, including larch (Larix kaempferi), red pine (Pinus densiflora), Korean pine (Pinus koraiensis), cedar (Cryptomeria japonica), and cypress (Chamaecyparis obtusa), using near-infrared (NIR) spectra. Fifty lumber samples were collected for each species. After air-drying the lumber, the NIR spectra (wavelength = 780-2500 nm) were acquired on the wide face of the lumber samples. Soft independent modeling of class analogy (SIMCA) was performed to classify the five species using their NIR spectra. Three types of spectra (raw, standard normal variated, and Savitzky-Golay $2^{nd}$ derivative) were used to compare the classification reliability of the SIMCA models. The SIMCA model based on Savitzky-Golay $2^{nd}$ derivatives preprocessing was determined as the best classification model in this study. The accuracy, minimum precision, and minimum recall of the best model (PCA models using Savitzky-Golay $2^{nd}$ derivative preprocessed spectra) were evaluated as 73.00%, 98.54% (Korean pine), and 67.50% (Korean pine), respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1998.06a
• /
• pp.79-82
• /
• 1998

Film characteristics of thin ONO dielectric layers for MONOS(metal-oxide-nitride-oxide-semiconductor) EEPRM was investigated by AES and AFM. Second derivative spectra of AES Si LVV overlapping peak provided useful information for chemical state analysis of superthin film. The ONO films with dimension of tunneling oxide 24${\AA}$, nitride 33${\AA}$, and blocking oxide 40${\AA}$ were fabricated. During deposition of the LPCVD nitride films on tunneling oxide, this thin oxide was nitrized. When the blocking oxide were deposited on the nitride film, the oxygen not only oxidized the nitride surface, but diffused through the nitride. The results of ONO film analysis exhibits that it is made up of SiO$_2$(blocking oxide)/O-rich SiON(interface/N-rich SiON(nitride)/-rich SiON(interface)/N-rich SiON(nitride)/O-rich SiON(tunneling oxide).