• 한국광학회지
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• 제31권3호
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• pp.125-133
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• 2020

본 논문에서는 다변량 분석법과 결합된 레이저 유도 플라즈마 분광법을 사용하여 겹친 유류 지문을 분리하는 혁신적인 방법을 연구하였다. LIPS는 겹친 유류 지문의 화학 성분에 대한 데이터뿐 아니라 실시간 분석 및 고속 스캐닝이 가능한 분광법이다. 레이저 유도 플라즈마 분광법을 통해 도출된 스펙트럼은 적절한 다변량 분석이 적용되어 법의학적 분류와 겹친 유류 지문의 재구성에 유용한 화학적 성분을 제공한다. 본 연구에서는 LIPS 스펙트럼에서 4가지의 유류 지문을 분류하기 위하여, 주성분 분석 방식과 부분 최소 제곱 회귀 분석을 사용하였다. 제안된 방법은 SIMCA 및 PLS-DA와 같은 구별 방식을 사용하여 4개의 유류 지문의 분류를 성공적으로 입증하였다. 본 연구의 결과는 대략 85% 이상의 정확도를 가졌으며, external validation 실험에서도 분류의 가능함을 보였다. 최종적으로, 125 ㎛의 공간 간격으로 레이저 스캐닝 분석을 통한 겹친 유류 지문의 2차원 형태의 분리가 가능함을 입증하였다.

• Bulletin of the Korean Chemical Society
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• 제35권12호
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• pp.3427-3432
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• 2014

This study introduces a new method of combining Imaging Differential Optical Absorption Spectroscopy (Imaging-DOAS) data and plume dispersion formulas for power plant emissions to determine the three-dimensional structure of a dispersing pollution plume and the spatial distributions of trace gas volume mixing ratios (VMRs) under conditions of negligible water droplet and aerosol effects on radiative transfer within the plume. This novel remote-sensing method, applied to a power plant stack plume, was used to calculate the two-dimensional distributions of sulfur dioxide ($SO_2$) and nitrogen dioxide ($NO_2$) VMRs in stack emissions for the first time. High $SO_2$ VMRs were observed only near the emission source, whereas high $NO_2$ VMRs were observed at locations several hundreds of meters away from the initial emission. The results of this study demonstrate the capability of this new method as a tool for estimating plume dimensions and trace gas VMRs in power plant emissions.

• 한국결정학회지
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• 제12권4호
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• pp.212-215
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• 2001

NaOAC·3H₂O 존재 하에서, manganese nitrate(Mn(NO₃)₂·H₂O )와 imidzole-4,5-dicarboxylic acid(IDCH₂)가 수열반응하여, 실험식 [Mn(IDC)(H₂O)]을 가지는 2차원 배위고분자 합성되었다. 화합물 1의 구조가 분광학적 방법(IR) 및 X-ray 회절법으로 규명되었다. 화합물의 1의 결정학적 자료: 사방정계 공간군 Pbca, a=7.257(5) Å b=13.687(5)Å, c=14.332(6)Å Z=8, R(wR₂)=0.0498(0.0999).

• 반도체디스플레이기술학회지
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• 제17권3호
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• pp.31-35
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• 2018

Tungsten disulfide($WS_2$) thin films were directly deposited by direct-current(DC) sputtering and annealed by rapid thermal processing(RTP) to materialize two-dimensional p-type transition metal dichalcogenide (TMDC) thin films on soda-lime glass substrates without any complicated exfoliation/transfer process. $WS_2$ thin films deposited at various DC sputtering powers from 80 W to 160W were annealed at different temperatures from $400^{\circ}C$ to $550^{\circ}C$ considering the melting temperature of soda-lime glass. The optical microscope results showed the stable surface morphologies of the $WS_2$ thin films without any defects. The X-ray photoelectron spectroscopy (XPS) results and the Hall measurement results showed stable binding energies of W and S and high carrier mobilities of $WS_2$ thin films.

• 한국지하수토양환경학회지:지하수토양환경
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• 제23권6호
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• pp.104-113
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• 2018

A three-dimensional electrochemical process using nanosized zero-valent iron (NZVI)/activated carbon (AC) particle electrode and persulfate (PS) was developed for oxidizing pollutants. X-ray diffraction (XRD), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), and Brunauer-Emmett-Teller (BET) surface area analysis were performed to characterize particle electrode. XRD and SEM-EDS analysis confirmed that NZVI was impregnated on the surface of AC. Compared with the conventional two-dimensional electrochemical process, the three-dimensional particle electrode process achieved three times higher efficiency in phenol removal. The system with current density of $5mA/cm^2$ exhibited the highest phenol removal efficiency among the systems employing 1, 5, and $10mA/cm^2$. The removal efficiency of phenol increased as the Fe contents in the particle electrode increased. The particle electrode achieved more than 70% of phenol removal until it was reused for three times. The sulfate radical played a predominant role in phenol removal according to the radical scavenging test.

• Journal of Gastric Cancer
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• 제3권3호
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• pp.151-157
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• 2003

Purpose: In this study, we attempted to ascertain the proton magnetic resonance spectroscopy (${1}^H$ MRS) peak characteristics of human gastric tissue layers and finally to use the metabolic peaks of MRS to distinguish between normal and abnormal gastric specimens. Materials and Methods: Ex-vivo ${1}^H$ MRS examinations of thirty-five gastric specimens were performed to distinguish abnormal gastric tissues invaded by carcinoma cells from normal stomach-wall tissues. High-resolution 400-MHz (9.4-T) ${1}^H$ nuclear magnetic resonance (NMR) spectra of two gastric layers, a proper muscle layer, and a composite mucosasubmucosa layer were compared with those of clinical 64- MHz (1.5-T) MR spectra. Three-dimensional spoiled gradient recalled (SPGR) images were used to determine the size and the position of a voxel for MRS data collection. Results: For normal gastric tissue layers, the metabolite peaks of 400-MHz ${1}^H$ MRS were primarily found to be as follows: lipids at 0.9 ppm and 1.3 ppm; alanine at 1.58 ppm; N-acetyl neuraminic acid (sialic acid) at 2.03 ppm; and glutathione at 2.25 ppm in common. The broad and featureless featureless spectral peaks of the 64-MHz MRS were bunched near 0.9, 1.3, and 2.0, and 2.2 ppm in human specimens without respect to layers. In a specimen (Borrmmann type III) with a tubular adenocarcinoma, the resonance peaks were measured at 1.26, 1.36 and 3.22 ppm. All the peak intensities of the spectrum of the normal gastric tissue were reduced, but for gastric tumor tissue layers, the lactate peak split into 1.26 and 1.39 ppm, and the peak intensity of choline at 3.21 ppm was increased. Conclusion: We found that decreasing lipids, an increasing lactate peak that split into two peaks, 1.26 ppm and 1.36 ppm, and an increasing choline peak at 3.22 ppm were markers of tumor invasion into the gastric tissue layers. This study implies that MR spectroscopy can be a useful diagnostic tool for gastric cancer.

• 한국작물학회지
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• 제49권4호
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• pp.342-348
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• 2004

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the $60\%$ isopropanol extract of soybean(Glycine max [L.] Merr.) seed revealed two abundant proteins with molecular masses of 19 and 10 kDa. Amino acid analysis revealed that the isopropanol-extractable protein fraction was rich in cysteine. Two-dimensional gel electro-phoretic analysis indicated that the 19kDa and 10kDa proteins had pI of 4.2 and 4.0 respectively. Peptide mass fingerprints of trypsin digests of the two proteins obtained using matrix-assisted, laser desorption/ionization-time of flight (MALDI-TOF) mass spectroscopy revealed the 19kDa protein was Kunitz trypsin inhibitor and the 10kDa protein was Bowman-Birk proteinase inhibitor. When resolved under non-denaturing conditions, the isopropanol-extracted proteins inhibited trypsin and chymotrypsin activity. Results presented in this study demonstrate that isopropanol extraction of soybean seed could be used as a simple and rapid method to obtain a protein fraction enriched in Kunitz trypsin and Bowman-Birk proteinase inhibitors. Since proteinase inhibitors are rich in sulfur amino acids and are putative anticarcinogens, this rapid and inexpensive isolation procedure could facilitate efforts in nutrition and cancer research.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.167.1-167.1
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• 2016

The interaction between adsorbed water and hydrogen on metallic surfaces is important for fundamental understanding of heterogeneous catalysis and electrode surface reactions in acidic environment. Here, we explore a long-standing question of whether hydronium ion can exist or not on a Pt surface coadsorbed with atomic hydrogen and water. Studies based on mass spectrometry and infrared spectroscopy show clear evidence that hydrogen atoms are converted into hydrated protons on a Pt(111) surface. The preferential structures of hydrated protons are identified as multiply hydrated $H_5O_2{^+}$ and $H_7O_3{^+}$ species rather than as hydronium ions. The multiply hydrated protons may be regarded as two dimensional zundel ($H_5O_2{^+}$) and Eigen cation ($H_7O_3{^+}$) in water-metal interface. These surface-bound hydrated protons may be key surface intermediates of the electrochemical interconversion between adsorbed hydrogen atoms and solvated protons.

• Bulletin of the Korean Chemical Society
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• 제24권8호
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• pp.1061-1068
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• 2003

The correlation between the water and N-methylacetamide (NMA) intramolecular vibrational frequencies and the hydrogen-bond length in a variety of NMA-H₂O and NMA-D₂O complexes was investigated by carrying out ab initio calculations. As the hydrogen-bond length decreases, the frequencies of bending and stretching modes of the hydrogen-bonding water increases and decreases, respectively, and the amide I and II (III) mode frequencies of the NMA decreases and increases, respectively. In this paper, correlation maps among the amide (I, II, and III) modes of NMA and three intramolecular water modes are thus established, which in turn can be used as guidelines for interpreting two-dimensional vibrational spectra of aqueous NMA solutions.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2010년도 추계학술발표논문집 1부
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• pp.470-473
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• 2010

Graphene, consisting of a single layer of carbon in a two-dimensional lattice, has been emerging as a fascinating material with many unique physical, chemical and mechanical properties. In this study, graphenes were prepared by a chemical method. To develop high performance polymer nanocomposites reinforced by graphenes, adequate dispersion of the fillers and strong interfacial bonding between the fillers and the polymer matrix are essential. The purpose of this study was to examine the influence of introducing amine groups on the surfaces of graphenes. FT-IR spectroscopy, SEM were used to confirm the functionalization. Epoxy nanocomposites comprising the graphenes were prepared and their characteristics were investigated by DSC, DMA and TMA. Fracture surfaces of the nanocomposites were investigated by SEM. The functionalized graphenes induced strong interfacial bonding than the pristine graphenes and resulted in considerable improvements in the performance of the nanocomposites.