• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.398-398
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• 2013

The electronic properties and the local structure of tantalum oxide thin film with variation of oxygen flow rate ranging from 9.5 to 16 sccm (standard cubic centimeters per minute) have been investigated by X-ray photoelectron spectroscopy (XPS), Reflection Electron Energy Loss Spectroscopy (REELS), and X-ray absorption spectroscopy (XAS). The XPS results show that the Ta4f spectrum for all films consist of the strong spin-orbit doublet $Ta4f_{7/2}$ and $Ta4f_{5/2}$ with splitting of 1.9 eV. The oxygen flow rate of the film results in the appearance of new features in the Ta4f at binding energies of 23.2 eV, 24.4 eV, 25.8, and 27.3 eV, these peaks attribute to $Ta^{1+}$, $Ta^{2+}$, $Ta^{4+}$/$Ta^{2+}$, and $Ta^{5+}$, respectively. Thus, the presence of non-stoichiometric state from tantalum oxide ($TaO_x$) thin films could be generated by the oxygen vacancies. The REELS spectra suggest the decrease of band gap for tantalum oxide thin films with increasing the oxygen flow rate. The absorption coefficient ${\mu}$ and its fine structure were extracted from the fluorescence mode of extended X-ray absorption fine structure (EXAFS) spectra. In addition, bond distances (r), coordination numbers (N) and Debye-Waller factors (${\sigma}^2$) each film were determined by a detailed of EXAFS data analysis. EXAFS spectrapresent both the increase of coordination number of the first Ta-O shell and a considerable reduction of the Ta-O bond distance with the increase of oxygen flow rate.

• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2531-2536
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• 2010

Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations have been employed to investigate the molecular structures and absorption spectra of two dyes containing diphenylaniline and 4-diphenylamino-diphenylaniline as donor moiety (TPA1 and TPA3). The geometries indicate that the strong conjugation is formed in the dyes. The electronic structures suggest that the intramolecular charge transfer from the donor to the acceptor occurs, and the electron-donating capability of 4-diphenylamino-diphenylaniline is stronger than that of diphenylaniline. The computed highest occupied molecular orbital (HOMO) energy levels are -5.31 and -4.90 eV, while the lowest unoccupied molecular orbital (LUMO) energies are -2.29 and -2.26 eV for TPA1 and TPA3, respectively, revealing that the interfacial charge transfer between the dyes and the semiconductor electrode are electron injection processes from the photon-excited dyes to the semiconductor conduction band. Furthermore, all the experimental absorption bands of TPA1 and TPA3 have been assigned according to the TDDFT calculations.

• Journal of the Korean institute of surface engineering
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• v.27 no.2
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• pp.65-73
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• 1994

Effects of deposition parameter on the ionic conductivity and structural change of the Lithium borosili-cate solid electrolyte films, prepared by rf sputtering using 7$LI_2O-3B_2O_3-1SiO_2$ single phase target and also a mosaic target enriched with $LI_2O$, were analyzed by measuring AC impedance and IR absorption spectra for the films. Thed solid electrolyte film deposited from the single phase target exhibited very low ionic conductivi-ty of $10^{-10}{\Omega}^{-1}cm{-1}$ at room temperature, a result of low $Li^+$ ion content(7.52 at%) in the film. The $Li^+$ con-ductivity for the films deposited from the mosaic target, however, significantly increased to $10^{-7}{\Omega}^{-1}cm{-1}$ due to both an increased $Li^+$content (14.75 at %) and a structural change of the films. The increased ionic conduc-tivity of the film appears to be associated with an easiness of ionic mobility by structural change of glassy film from a some close packed network structure to a open one. These structural changes of film were found to be closely related to the increase in the peak intensity at~$960cm^{-1}$ of IR absorption spectra for the glassy films. With increasing either argon pressure from 3 to 21 mtorr or rf power from 2 to 3 W/$cm^2$, the $Li^+$ conduc-tivity for the films significantly increased to an order of $10^{-6}{\Omega}^{-1}cm{-1}$ due to an increase in openness of film structure, as confirmed by both an increase in the IR absorption peak intensity at ~$960cm^{-1}$ and a resultant reduction of activation energy for mobility of $Li^+$ ion.

• Journal of the Korean Chemical Society
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• v.30 no.1
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• pp.84-89
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• 1986

A newflexible $N_2O_2$-type tetradentate ligand. Ethylenediamine-N,N'-di-${\alpha}$-isobutyric acid(eddib), has been synthesized, and dichloro cobalt(III) complex of eddib has been prepared via the air-oxidation technique. Only S-cis isomer has been yielded during the preparation of complex. Ring strain and steric hinderance are cited as the cause for the preference for the S-cis geometric configuration. On series of cobalt(III) complexes of eddib, $[Co(eddib)L]^{n+}$ $(L = Cl{\cdot}(H_2O),\;CO_3^{2-},\;(H_2O)_2)$have been prepared in situ. In their electronic absorption spectra, the absorption maxima and their intensities of the above series of complexes are on the ordinary line of the spectrochemical and hyperchromic series. Elemental analysis, IR, NMR and electronic absorption spectra have been used to characterize the complex and geometries of the complex.

• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.404-407
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• 1992

This study was conducted to determine the effect of the physical and chemical factors on the absorbance when the chemical component of food was rapidly and effectively analyzed with near infrared reflection spectrophotometer. The absorbance was measured within the wavelength range of 1100 and 2500m and at the various sample temperatures. The absorbance was greatly increased with the rising sample temperature. When the grinding time of samples prolonged, the absorbance was decreased. The absorption peaks occurring in the near infrared spectra of meat, meat protein, pork fat and water were attributed to the overtone and combination vibration of C-H, N-H, O-H or C=O bond within the macromolecules of each sample. The absorbance was lower for meat protein than other meat components. Pork fat was characterized by the ${\cdot}CH_2{\cdot}$ absorption peak at the wavelength of 1700 and 2300 nm and water by the relatively high absorption peak at the wavelength of 1450 and 1930 nm. As a result, the absorbance of near infrared reflection spectrum of meat was affected mainly by fat and water in meat.

• Membrane Journal
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• v.5 no.2
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• pp.89-96
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• 1995

The monolayer characteristics of phosphate amphiphiles with azobenzene at air/water interface were studied by the measurment of $\pi-A$ curves and absorption spectra. Immediately after being spread on the water surface, these amphiphiles having strong intermolecular hydrogen bonding interactions showed the typical absorption spectra which resulted from domain formation. But the aggregated domains could be controlled by changing the subphase conditions (adding bulky salt and rasing pH). Addition of metal ions in subphase changes the molecular orientation of monolayer. As the metal ion charge increases ($1\leq2$ < 3 < 4 valence), the absorption maximum (310nm) of the amphiphile with azobenzene shifts to a longer wavelength (350nm) which means that the orientation of the amphiphile is tilted. These results suggest that the molecular orientation, and furthermore the aggregation state of monolayer can be possibly controlled by the interaction of metal ions with different charge types.

• Polymer(Korea)
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• v.34 no.4
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• pp.376-380
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• 2010

Donor-$\pi$-acceptor (D-$\pi$-A) type chromophore-based polymers were newly synthesized. These polymers exhibited absorption peak due to intramolecular charge transfer (ICT) in a visible range as well as absorption peak due to carbonyl group in both solution and film state by measuring UV visible spectra. The addition of $Eu^{3+}$ ion into the polymers induced red-shift in absorption due to ICT and the color changes from yellow to red in the solution and film were observed by naked eyes. The contents of crosslinking agent influenced the features and solubility of the polymers. In addition, the contents of crosslinking agent and the $Eu^{3+}$ ion addition improved film-forming ability.

• Journal of Astronomy and Space Sciences
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• v.16 no.2
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• pp.105-114
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• 1999

Archival long-slit spectra, covering the wavelength range 4050~5150$\AA$, have been used to investigate the radial behavior of absorption line features (G4300, Fe4383, Ca4455, Fe44531, Fe4668, and H$\beta$) of an eliptical galaxy NGC 5322. The heliocentric recession velocity of NGC 5322 has been derived as 1888$\pm$51kms-1. Metallic absorption lines of NGC 5322 show significant radial gradients through the major axis. The minor axis shows much smaller radial metal line gradients than the major axis. The minor axis shows much smaller radial metal line gradients than the major axis. The mean slopes of Fe line gradients to the major and minor axes of NGC 5322 were estimated as -0.433$\pm$0.064 and -0.242$\pm$0.096, respectively. Significant radial gradients of H$\beta$ absorption of NGC 5322 are also detected both on the major and minor axes. It is shown that the radial metallicity gradients in NGC 5322 are smaller than expected in a simple dissipative collapse model. Rather, dissipationless collapse, such as hierarchical merhing, could have contributed during the initial stage of the galaxy formation.

• Journal of the Optical Society of Korea
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• v.13 no.2
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• pp.279-285
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• 2009

Prediction of glucose concentration in the interstitial fluid (ISF) based on mid-infrared absorption spectroscopy was examined at the glucose fundamental absorption band of 1000 - 1500/cm (10 - 6.67 um) using multi-component analysis. Simulated ISF samples were prepared by including four major ISF components. Sodium lactate had absorption spectra that interfere with those of glucose. The rest NaCl, KCl and $CaCl_2$ did not have any signatures. A preliminary experiment based on Design of Experiment, an optimization method, proved that sodium lactate influenced the prediction accuracy of glucose. For the main experiment, 54 samples were prepared whose glucose and sodium lactate concentration varied independently. A partial least squares regression (PLSR) analysis was used to build calibration models. The prediction accuracy was dependent on spectrum preprocessing methods, and Mean Centering produced the best results. Depending on calibration sample sets whose sodium lactate had different concentration levels, the standard error prediction (SEP) of glucose ranged $17.19{\sim}21.02\;mg/dl$.

• The Korean Journal of Food And Nutrition
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• v.2 no.1
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• pp.18-26
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• 1989

The objective of this study was to improved the limited functional characteristics of mungbean whole globulin. The mungbean whole globulin was acylated with succinic and acetic anhydride, and the functional properties of acylated protein were investigated, The results obtained ware as follows. 1. The UV-absorption spectra of acylated whole globulins with that of the succinylated 74% whole globulin as large blue shift of the absorption maximum and minimum wavelength from 275 nm to 269 nm, respectively. 2. The mobility of acylated whole globulin were increased on PAGE pattern, and degree of mobility was particularly remarkable in case of succinylation, 3. The water absorption capacity of whole globulin was increased by acylation. The most increased rate of whole globulin was 174,02% from succinylated 74%. The oil absorption capacity of whole globulin was increased by acylation The most increased rate of whole globulin was 165.41% from acetylated 81.77%. 4. The bulk density of whole globulin was decreased by acylation. and the greater the extent of acylation, the smaller the bulk density. 5. The foaming capacity and stability of whole globulin was increased by acylation, and remarkably high in 74% succinylated whole globulin. In contrast, however, the foaming capacity and stability of native and acylated whole globulin were decreased by heat treatment.