• Bulletin of the Korean Chemical Society
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• v.35 no.5
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• pp.1413-1416
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• 2014

A novel topological index (TG Index) has been introduced. The graphical matrix representation of the TG index includes the use of directed subgraphs for the first time in graph theory literature. The application of the TG index on certain properties of polyenes yielded very well correlation data.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.1019-1021
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• 2002

In place of $Alq_3$ for EL, various Zn-Complex with fluorenscent chromophores were synthesized. PL of Zn-Complex substituted with electron donor group at 2 or 4 position occurred to bathochromic shift of emission$(\lambda_{max})$ and PL intensity was weaker than Zn-Complex non-substituted with electron donor group.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.9-16
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• 2006

소정의 조건을 만족하는 서로 다른 주문들의 일부 혹은 전부가 동일 배치에 집약하여 처리할 수 있을 때, 최소개수의 작업단위로 모든 주문을 처리하는 문제를 다룬다. 무방향 그라프(G=(V,E,w(v)))와 작업 단위 크기 $\lambda$로 표현되는 이 문제는 엔피하드(NPhard)일 뿐 아니라 맥스에스엔피하드(MAX SNP-hard)임을 보인다. 또한, 그라프가 나무(Tree)구조일 때에 대한 O(|V|log|V|) 계산 복잡도를 갖는 최적 알고리듬을 제시한다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1086-1090
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• 1997

Morphological properties on lintnerized maize starches with different amylose content were investigated. With increasing the lintnerization periods and decreasing the amylose content, hydrolysis rate was increased. As amylose content of starch was increased, the degree of damage with acid treatment was decreased by SEM. With increasing hydrolysis, iodine affinity, apparent amylose content and ${\lambda}_{max}$ of lintnerized starches were decreased. Water binding capacities of lintnerized starches were higher than those of native starches.

• Journal of the Korean Geotechnical Society
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• v.24 no.8
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• pp.125-135
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• 2008

Rigid-soft particle mixtures, which consist of sand and rubber, are investigated for the understanding of the stress-deformation and elastic moduli. Specimens are prepared with various size ratio sr between sand and rubber particles, and different volumetric sand fraction sf. Small strain shear waves are measured under $K_o$-loading condition incorporated with the stress-deformation test by using oedometer cell with bender elements. The stress-deformation and small strain shear wave characteristics of rigid-soft particle mixtures show the transition from a rigid particle behavior regime to a soft particle behavior regime under fixed size ratio. A sudden rise of $\Lambda$ factor and the maximum value of the $\zeta$ exponent in $G_{max}=\;{\Lambda}({\sigma}'_{o}/kPa)^{\zeta}$ are observed at $sf\;{\approx}\;0.4{\sim}0.6$ regardless of the size ratio sf. Transition mixture shows high sensitivity to confining stress. The volume fraction for the minimum porosity may depend on the applied stress level in the rigid-soft particle mixtures because the soft rubber particles easily distort under load. In this experimental study, the size ratio and volumetric sand fraction are the important factors which determine the behavior of rigid and soft particle mixtures.

• Journal of Korean Society of Forest Science
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• v.26 no.1
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• pp.7-12
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• 1975

The sap uses of Korean sugar maple, Acer mono Max., "Gorosoe-namoo," the most abundant growing stock in maples, for a medical beverage at every early spring have had the long history in Korea. The sap of Korean sugar maple (the maple) was prepared with a unique tapping method from the trees during the sap flow season of 1974, measured the sugar content in $2.6^{\circ}$ to $3.3^{\circ}Brix$ of sugar on average and the sugar concentration of the sap was enough for a sweetener resource comparing with those of American sugar maples in literature. The color of sirup was very dark and the color index was 2.69 for the sirup of $15.3^{\circ}Brix$ having 10 hours evaporation and 3.380 for the standard sirup, as shown in Table 3 and Figure 2, due to the prolonged evaporation in deep aluminium or stainless steel kettles. The alcohol extractives of standard sirup has the light color and the residue reddish brown and the absorption spectra have the maxima in wave length of 350 nm, 1,000 nm, 1,170 nm, 1,400 nm and 1900 nm, as shown in Figure 3. The extractives of ethanol and monoethanolamine mixture (97:3, v/v) has dark red and the residue darker redish brown.

• Journal of the Korean Chemical Society
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• v.30 no.5
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• pp.456-464
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• 1986

The complex formation of branched poly(ethylene imine) (BPEI) with bivalent transition metal ions, such as Fe(II), Co(II), Ni(II) and Cu(II), have been investigated in terms of visible absorption and pH titration methods in an aqueous solution in 0.1M KCl at 30${\circ}$. The stability constants for M(II)-BPEI complexes was calculated with the modified Bjerrum method. The formation curves of M(II)-BPEI complexes showed that Fe(II), Co(II), Ni(II) and Cu(II) ions formed coordination compounds with four, two, two, and two ethylene imine group, respectively. In the case of Cu(II)-BPEI complex at pH 3.4 ∼ 3.8, ${\lambda}_{max}$ was shifted to the red region with a decrease in the acidity. The overall stability constants (log $K_2$) increased as the following order, Co(II) < Cu(II) < Ni(II) < Fe(II).

• Bulletin of the Korean Chemical Society
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• v.27 no.3
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• pp.368-372
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• 2006

The cobalt titanate, $CoTiO_3$ nanoparticles have been prepared by calcinations of precursor obtained from a mixture of $TiO_2$ and $Co(OH)_2$ in aqueous cetyltrimethylammonium bromide (CTAB) solution. The nanoparticles were investigated with X-ray powder diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric/differential thermal analysis (TGA/DTA) to determine the crystallite size and the phase composition. The spectroscopic characterizations of these nanoparticles were also done with UV-Vis spectroscopy and FT-Raman spectroscopy. XRD patterns show that $CoTiO_3$ phase was formed at calcinations temperature above 600 ${^{\circ}C}$. UV-Vis absorption spectra indicate that the $CoTiO_3$ nanoparticles have significant red shift to the visible region (400-700 nm) with $\lambda_{max}$ = 500 nm compared to pure $TiO_2$ powder ($\lambda_{max}$ = 320 nm). The new absorption peaks (absorption at 696, 604, 520, 478,456, 383, 336, 267, 238, 208 $c m ^{-1}$), which were not appeared in FT-Raman spectra of P-25, also confirm the formation of Ti-O-Co bonds at above 600 ${^{\circ}C}$ and just not the mixtures of titanium dioxide with cobalt oxides.

• Bulletin of the Korean Chemical Society
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• v.26 no.5
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• pp.795-801
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• 2005

New PPV derivatives which contain electron-withdrawing trifluoromethyl ($CF_3$) group, poly[2-(2-ethylhexyloxy)-5-(4-trifluoro methylphenyl)-1,4-phenylenevinylene] (EH$CF_3$P-PPV), and poly[2-(2-ethylhexyloxy)-5-(3,5-bis(trifluoromethyl)-phenyl)-1,4-phenylenevinylene] (EHB$CF_3$P-PPV), have been synthesized by GILCH polymerization. As the result of the introduction of the electron-withdrawing $CF_3$ group to the phenyl substituent, the LUMO and HOMO energy levels of EH$CF_3$P-PPV (2.8, 5.1 eV) and EHB$CF_3$P-PPV (3.0, 5.3 eV) were lower than those of known poly[2-(2-ethylhexyloxy)-5-phenyl-1,4-phenylenevinylene] (EHP-PPV) (2.6, 4.9 eV). These polymers have been used as the electroluminescent (EL) layers in double layer lightemitting diodes (LEDs) (ITO/PEDOT/polymer/Al). EH$CF_3$P-PPV, and EHB$CF_3$P-PPV show maximum photoluminescence (PL) peaks at ${\lambda}_{max}$ = 550, 539 nm, and maximum EL peak at ${\lambda}_{max}$ = 545, 540 nm, respectively. The current-voltage-luminance (I-V-L) characteristics of the polymers show that turn-on voltages of EH$CF_3$P-PPV and EHB$CF_3$P-PPV are around 4.0 and 3.5 V, respectively.

• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.599-605
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• 2016

Serratia marcescens, a Gram-negative bacterium characterized by production of a nondiffusible red pigment. Serratia marcescens 2354 (ATCC 25419) was production and purification a high concentration of red pigments when growing on Cang's soytone (CS) culture broth with soytone and ethanol. The optimal temperature and intial pH range for the production of the red pigments were $28^{\circ}C$ and pH 7.5, respectively. The red pigments was separated and purified through organic solvents extraction. Characterization of the red pigments is studied by UV-spectrophotometer at ${\lambda}_{max}$ 537 nm. The HPLC-Mass analysis of the partially purified compounds showed two major peaks with the molecular masses of 537 and 565 g. The red pigments were stable at room temperature under the acidic pH (up to pH 6) but were unstable at the strong alkaline condition. And red pigments were stable at sun light.