• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 1996년도 추계학술대회 초록집
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• pp.24-24
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• 1996

• 한국고분자학회지:고분자과학과기술
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• 제26권3호
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• pp.221-225
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• 2015

• Bulletin of the Korean Chemical Society
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• 제23권2호
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• pp.189-194
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• 2002

Two-photon resonant third photon ionization of atomic bromine $(4p^5\;^2P_{3/2}\;and\;^2P_{1/2})$ has been studied using a photoelectron imaging spectroscopy in the wavelength region 250 - 278 nm. The technique has yielded simultaneously both relative branching ratios to the three levels of $Br^+(^3P_2,\;^3P_{0.1}\;and^1D_2)$ with $4p^4$ configuration and the angular distributions of outgoing photoelectrons. The product branching ratios reveal a strong propensity to populate particular levels in many cases. Several pathways have been documented for selective formation of $Br^+(^3P_2)$ and $Br^+(^3P_{0.1})$ ions. In general, the final ion level distributions are dominated by the preservation of the ion core configuration of a resonant excited state. Some deviations from this simple picture are discussed in terms of the configuration interaction of resonant states and the autoionization in the continuum. The photoelectron angular distributions are qualitatively similar for all transitions, with a positive $A_2$ anisotropy coefficient of 1.0-2.0 and negligible $A_4$ in most cases, which suggests that the angular distribution is mainly determined by the single-photon ionization process of a resonant excited state induced from the third photon absorption.

• Journal of Biosystems Engineering
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• 제40권4호
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• pp.394-408
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• 2015

Spectroscopy is an emerging technology for the quality assessment of pharmaceutical samples, from tablet manufacturing to final quality assurance. The traditional methods for the quality management of pharmaceutical tablets are time consuming and destructive, while spectroscopic techniques allow rapid analysis in a non-destructive manner. The advantage of spectroscopy is that it collects both spatial and spectral information (called hyperspectral imaging), which is useful for the chemical imaging of pharmaceutical samples. These chemical images provide both qualitative and quantitative information on tablet samples. In the pharmaceutics, spectroscopic techniques are used for a variety of applications, such as analysis of the homogeneity of powder samples as well as determination of particle size, product composition, and the concentration, uniformity, and distribution of the active pharmaceutical ingredient in solid tablets. This review paper presents an introduction to the applications of various spectroscopic techniques such as hyperspectroscopy and vibrational spectroscopies (Raman spectroscopy, FT-NIR, and IR spectroscopy) for the quality and safety assessment of pharmaceutical solid dosage forms. In addition, various chemometric techniques that are highly essential for analyzing the spectroscopic data of pharmaceutical samples are also reviewed.

• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3326-3330
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• 2014

A quinoline-thiooxorhodamine conjugate fluorescent sensor (1) has been synthesized. Sensor 1 exhibits high selectivity and sensitivity to $Hg^{2+}$ in $H_2O$/DMSO (95/5, v/v, HEPES 20 mM, pH = 7.4) solution with fluorescence detection. Other tested metal ions do not induce any significant fluorescence intensity changes. Sensor 1 interacts with $Hg^{2+}$ through a 1:1 binding stoichiometry with a good anti-inference ability. In addition, fluorescent imaging of $Hg^{2+}$ in Hela cells is also successfully demonstrated.

• Bulletin of the Korean Chemical Society
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• 제29권10호
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• pp.2023-2025
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• 2008

To evaluate the potential of radioiodine labelled hypericin as a malignant glioma imaging agent, U-251 MG, U-373 MG, C6 glioma and fibroblast were treated with a I-123 labelled hypericin derivative and C6 glioma transplanted nude mouse were injected with a I-124 labelled hypericin derivative for a micro PET imaging. 2- Iodohypericin was prepared as a reference compound. In this paper, we describe the syntheses of 2- iodohypericin and 2-[$^{123}I/^{124}I$]iodohypericin and the results of a corresponding biological evaluation. In all glioma cell lines, 2-[$^{123}I$]iodohypericin uptake was increased in a time dependant manner and an accumulation of 2-[$^{124}I$]iodohypericin was observed in C6 glioma bearing nude mouse. These results suggest that radioiodine labelled hypericin can visualize a PKC overexpressed malignant glioma.

• Bulletin of the Korean Chemical Society
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• 제32권2호
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• pp.659-663
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• 2011

The photodissociation dynamics of bromobenzene near 234 nm has been investigated using a two-dimensional photofragment ion-imaging technique coupled with a state-selective [2+1] resonance-enhanced multiphoton ionization (REMPI) scheme. The nascent Br atoms are produced by the primary C-Br bond dissociation, which leads to the formation of $C_6H_5$ ($\tilde{X}$) and Br($^2P_j$, j = 1/2, 3/2). The observed translational energy distributions have been fitted by a single Boltzmann function and two Gaussian functions. Trimodal translational energy distributions of Br($^2P_j$) have been assigned to the direct/indirect dissociation mechanisms originating from the initially excited $^3({\pi},{\pi}^*)$ state. The assignments have been confirmed by the recoil anisotropy and distribution width corresponding to the individual components.

• Bulletin of the Korean Chemical Society
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• 제35권2호
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• pp.575-580
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• 2014

We uniformly coated Eu(III)- and Tb(III)-doped yttrium oxide onto the surface of $SiO_2$ spheres and then characterized them by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction crystallography and UV-Visible absorption. 2D and 3D photoluminescence image map profiles were reported for the core-shell type structure. Red emission peaks of Eu(III) were observed between 580 to 730 nm and assigned to $^5D_0{\rightarrow}^7F_J$ (J = 0 - 4) transitions. The green emission peaks of Tb(III) between 450 and 650 nm were attributed to the $^5D_4{\rightarrow}^7F_J$ (J = 6, 5, 4, 3) transitions. For annealed samples, Eu(III) ions were embedded at a $C_2$ symmetry site in $Y_2O_3$, which was accompanied by an increase in luminescence intensity and redness, while Tb(III) was changed to Tb(IV), which resulted in no green emission.

• 한국재료학회지
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• 제4권5호
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• pp.516-523
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• 1994

이논문에서는 metal organic chemical vapor deposition(MOCVD)에 의해서 성장된 InGaAsP/InP이종접합구조의 격자부정합이 Photoluminescence(PL)효율에 미치는 영향을 연구하였다. 격자부정합은 (400)과 {511} x-ray reflection을 통해 측정하였고, 부정합 전위의 유무는 x-ray to-pography와 PL imaging을 통해 확인했다. PL강도 측정결과, 상대적으로 높은 PL강도는 탄성적으로 스트레인을 받은 시료에, 낮은 PL강도는 전위로 인해 비탄성적으로 변형된 시료에서 얻어졌다. 성장온도에서 격자정합된 시료의 PL효율이 실온에서 가장 높은 것을 알 수 있었다. PL강도와 X-ray반치폭과 관계에서, 시료의 광전자 특성이 구조적 특성과 밀접하게 연관됨을 알 수 있었다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2017년도 춘계공동학술대회
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• pp.44-44
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• 2017

The objective of this study was to evaluate firmness, and sweetness index (SI) of tomatoes (Lycopersicum esculentum) by using hyperspectral imaging (HSI) in the range of 1000-1400 nm. The mean spectra of the 95 matured tomato samples were extracted from the hyperspectral images, and the reference firmness and sweetness index of the same sample were measured and calibrated with their corresponding spectral data by partial least squares (PLS) regression with different preprocessing method. The results showed that the regression model developed by PLS regression based on Savitzky-Golay (S-G) second-derivative preprocessed spectra resulted in better performance for firmness, and SI of tomatoes compared to models developed by other preprocessing methods, with correlation coefficients (rpred) of 0.82, and 0.74 with standard error of prediction (SEP) of 0.86 N, and 0.63 respectively. Then, the feature wavelengths were identified using model-based variable selection method, i.e., variable important in projection (VIP), resulting from the PLS regression analyses and finally chemical images were derived by applying the respective regression coefficient on the spectral image in a pixel-wise manner. The resulting chemical images provided detailed information on firmness, and sweetness index (SI) of tomatoes. Therefore, these research demonstrated that HIS technique has a potential for rapid and non-destructive evaluation of the firmness and sweetness index of tomatoes.