• 한국식품저장유통학회:학술대회논문집
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• 한국식품저장유통학회 1996년도 임시총회 및 제8차 학술발표회 진행표 및 발표논문 초록
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• pp.25-25
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• 1996

;Jindo Hongju is an unique red-colored traditional distilled wine of Korea. The unique attractive color of Jindo Hongju is due to the pigments of gromwell (Lithospermum erythrorhizon) root, derivatives of naphtoquinone such as shikonin and acetylshikonin. Which are extracted during the distillation process. The attractive color of the gromwell pigments is easily changed to dark red or to brown causing deterioration of the Quality of Jindo Hongju. Due to the discoloration of the pigments and to the limited supply of gromwell roots, some brewers manufacture spurious Jindo Hongju using artificial colorants. This study was performed to devise a simple method of detecting spurious Jindo Hongju products. The color of the gromwell pigments was greatly affected by pH change and the change could be demonstrated by the change of the absorption spectrum. At pH 4.0 the normal pH of Jindo Hongju, the absorption spectra of gromwell pigments and genuine Hongju products showed an absorption maximum of 520 nm. The absorption maximum was shifted to 570 nm and to 616 nm as the pH was raised to 7.0 and 11.0 respectively. This transition due to the pH change was also demonstrated on em chromaticity diagram. The characteristic transition due to pH change of gromwell pigment solution was not observed with an artificial colorant (red No.2) which was suspected to be used in the manufacture of imitation products. The absorption spectra of most of the Jindo Hongju collected from the market were similar to that of the gromwell pigments and showed the characteristic transition due to pH change with the addition of NaOH. However, with a few of the products, the absorption spectra was similar to that of the artificial colorant and the characteristic transition due to pH change was not observed, indicating these products might have been forged. The result of study suggests that the transition of the absorption spectrum and the change of the color due to pH change be used for the detection of imitation products. Farther more, since, at pH above 9.0, the color of the gromwell pigments and genuine Jindo Hongju could be visually differentiated from that of the artificial colorant and forged products, it might be possible that the forged products be easily detected by raising the pH to above 9.0 and visually comparing the color with that of the gromwell pigment at the same pH.me pH.

• Journal of Photoscience
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• 제9권2호
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• pp.460-462
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• 2002

Absorption spectra of biological specimens in the soft X-ray region have been presented with special reference to the XANES (X-ray absorption Near Edge Structure) of constituent elements. Absorption spectrum in this wavelength region is characterized by the absorption edges from which elemental content could be derived. In addition, XANES has a characteristic profile for chemical environment around the element such as chemical bond. Using the specific absorption peak we can assign not only the chemical bond but also molecules having such a chemical bond. In the present paper, absorption spectrum of DNA was measured in the wavelength range from 1.5nm to 5nm. Spectrum of Chinese Hamster Ovary (CHO) cells was compared with the DNA spectrum. XANES were distinct at the K absorption edges of major elements, C, N and O. In the spectrum of the cells prominent peaks at the L absorption edge of minor element Ca were also detectable. XANES profiles in small local areas in a cell could also be measured in combination with X-ray microscopy. These give information about local chemical environment in a cell. XANES at the phosphorus K absorption edge in a human HeLa cell was successfully obtained corresponding to a sharp and intensive XANES peak of DNA.

• 천문학회보
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• 제40권2호
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• pp.53.3-53.3
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• 2015

We analyzed both HCN J=1-0 and HNC J=1-0 line profiles to study the inflow motions in different evolutionary stages of massive star formation; infrared dark clouds (IRDCs), high-mass protostellar object (HMPOs), and ultra-compact HII regions (UCHIIs). The infall asymmetry in HCN spectra seems to be prevalent throughout all the three evolutionary phases, with IRDCs showing the largest excess in blue profile. In the case of HNC spectra, the prevalence of blue sources does not appear, excepting for IRDCs. We suggest that this line is not appropriate to trace infall motion in evolved stages of massive star formation because of an astrochemical effect. This result spotlights the importance of considering chemistry in dynamical study in star-forming regions. The fact that the IRDCs show the highest blue excess in both infall tracers indicates that the most active infall occurs in the early phase of star formation, i.e., the IRDC phase rather than in the later phases. However, the UCHIIs is likely still accreting matters. We also found that the absorption dips of the HNC spectra in all blue sources are red--shifted relative to their central velocities. These red-shifted absorption dips may indicate the observational signature of overall collapse although observations with better resolutions are needed to examine this feature more in detail.

• 천문학회보
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• 제37권1호
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• pp.76.2-76.2
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• 2012

The understanding spectral characterization of possible earth-like extra solar planets has generated wide interested in astronomy and space science. The technical central issue in observation of exoplanet is deconvolution of the temporally and disk-averaged spectra of the exoplanets. The earth model based on atmospheric radiative transfer method has been studied in recent years for solutions of characterization of earthlike exoplanet. In this study, we report on the current progress of the new method of 3D earth model as a habitable exoplanet. The computational model has 3 components 1) the sun model, 2) an integrated earth BRDF (Bi-directional Reflectance Distribution Function) model (Atmosphere, Land and Ocean) and 3) instrument model combined in ray tracing computation. The ray characteristics such as radiative power and direction are altered as they experience reflection, refraction, transmission, absorption and scattering from encountering with each all of optical surfaces. The Land BRDF characteristics are defined by the semi-empirical "parametric-kernel-method" from POLDER missions from CNES. The ocean BRDF is defined for sea-ice cap structure and for the sea water optical model, considering sun-glint scattering. The input cloud-free atmosphere model consists of 1 layers with vertical profiles of absorption and aerosol scattering combined Rayleigh scattering and its input characteristics using the NEWS product in NASA data and spectral SMARTS from NREL and 6SV from Vermote E. The trial simulation runs result in phase dependent disk-averaged spectra and light-curves of a virtual exoplanet using 3D earth model.

• Bulletin of the Korean Chemical Society
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• 제25권6호
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• pp.889-894
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• 2004

Polyaddition reactions of 1,1-diethynyl-3-triethylsilyl-1-silacyclopent-3-ene with several organoborane derivatives have afforded the oligomeric materials containing organosilacyclic group and organoboron moiety along the oligomer main chains. All of these materials are soluble in THF as well as chloroform, and their molecular weights are in the range of 1,990/1,190-21,950/7,050 ($M_w/M_n$) with the polydispersity indexes of 1.67-3.43. The prepared oligomers are characterized by several spectroscopic methods such as $^1H,\;^{13}C, \;^{29}Si,\;^{11}B$ NMR and FTIR spectra along with elemental analysis. FTIR spectra of all the oligomers show that the new strong C=C stretching frequencies appear at 1599-1712 $cm^{-1}$, in particular. The UV-vis absorption spectra of the materials in THF solution exhibit the strong absorption bands at the ${\lambda}_{max}$ of 268-275 nm. The oligomeric materials show that the strong excitation peaks appear at the ${\lambda}_{max}$ of 255-279 nm and the strong fluorescence emission bands at the ${\lambda}_{max}$ of 306-370 nm. All the spectroscopic data suggest that the obtained materials contain both the organoboron ${\pi}$-conjugation moiety of C=C-B-C=C and the organosilacyclic group of 3-triethylsilyl-1-silacyclopent-3-ene along the oligomer main chains. The oligomers are thermally stable up to 162-200 $^{\circ}C$ under nitrogen.

• 한국결정성장학회지
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• 제14권6호
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• pp.233-235
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• 2004

Shaped single crystals of Bi : $Y_3Ga_5O_{12}$(Bi = 0.041, 0.047 and 0.061 mol%) were grown by the micro-pulling-down method. Optical absorption spectra show an absorption band at 288 nm ascribed to the lowest energy $6s^2$ \longrightarrow 6s6p transition of $Bi^{3+}$ , while luminescence spectra demonstrate the band at 314 nm ascribed to the reverse radiative transition of the excited $Bi^{3+}$ centres. At room temperature, dominant decay time component was found to be about 440 ns with a minor slower component 580 ns.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1184-1186
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• 1995

The absorption spectra of synthesis of azobenzene containing long chain fatty acids were investigated by UV spectrophotometer in chloroform solution. Also, the pressure-area isotherms of the molecules on the water-air interface were obtained and the LB films were fabricated onto a quartz slides and quartz crystals by the conventional Langmuir-Blodggett(LB) method. The UV absorption spectra of Langmuir-Blodggett(LB) films on quartz slides have been measured. From these measurements, following conclusions were obtained. Azobenzene containing long chain fatty acids show a photoisomerization by irradiation of UV light and visible light alternatively. At the pressure-area isotherms, the value of surface pressure increment were decreased when the number of $C_n$ increased. Also the LB films show a photoisomerization characteristics. So the LB film of azobenzene containing long chain fatty acid has possibility to being applied to functional molecular device such as photomemory and light switching.

• 대한화학회지
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• 제37권5호
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• pp.523-526
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• 1993

Photochromism을 나타내는 spiroxazine 색소의 흡수스펙트라 및 용매 효과에 관해 검토하였다. 그 결과 positive solvatochromism을 나타내었으며 이로부터 spiro 고리가 자외선 조사에 의해 개열되었을 때는 keto 형의 분자구조로 되어있음을 나타낸다는 것을 알 수 있었다. 색소골격내에 C 대신 N 원자가 존재하므로서 흡수극대치가 장파장측에 이동한다는 것을 ppp 분자궤도법(Pariser-Parr-Pople Molecular Orbital Method)을 사용해 정량적으로 해석하였다.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1204-1208
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• 2010

Anion recognition via hydrogen-bonding interactions could be monitored with changes in UV-vis absorption spectra and in some cases easily monitored with naked eye. Urea receptors 1 and 2 connected with both an azo group and a nitrophenyl group as a signaling group for color change proved to be an efficient naked eye receptor for the fluoride ion. The anion recognition phenomena of the receptors 1 and 2 via hydrogen-bonding interactions were investigated through UV-vis absorption and $^1H$ NMR spectra.

• Bulletin of the Korean Chemical Society
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• 제33권3호
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• pp.993-996
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• 2012

We investigated fluorescence and fluorescence excitation of diphenylsilane (DPS) in a solution and molecular beams in combination with the aid of the DFT method. When the molecule was photoexcited at 250 nm in a cyclohexane solution, normal and excimer fluorescences were observed in the ranges of 260-320 and 330-450 nm, respectively. The fluorescence excitation spectrum indicates that the channel leading to the intramolecular excimer formation is not efficient in comparison with the normal fluorescence. Vibrationally resolved fluorescence excitation spectra were measured for the DPS molecules cooled in pulsed supersonic expansion of He in the range 262.2-271.7 nm, in which we can see several electronic excitation spectra exhibiting the electronic band origins. We found that the simulated absorption spectrum based on the time-dependent densityfunctional theory calculations accords well with the absorption spectrum.