• 전기학회논문지P
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• 제57권3호
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• pp.332-337
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• 2008

We analyzed carbonization pattern and crystal structure of polyvinyl chloride wire by thermal stress. Copper that is oxidized at normal temperature is a reddish brown. If under the thermal stress range of 500 to 700 [$^{\circ}C$], carbonization and exfoliation occurrence. Section structure of electric wire is same as arrangement of particle in metallograph analysis. But, as thermal stress increases, size of particle is enlarged. Electric wire displays elongation structure in SEM image analysis and elongation structure collapses when receive thermal stress at 300 [$^{\circ}C$]. In EDX analysis, we get the spectra of CuL, CuK, OK, and ClK. FT-IR analysis was shown new spectra with in range of $1,440{\sim}1,430\;[cm^{-1}]$, 1,340 [$cm^{-1}$], 1,240 [$cm^{-1}$].

• 대한화장품학회지
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• 제42권3호
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• pp.297-302
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• 2016

본 연구에서는 $C_{12-20}$ 알킬글루코사이드, $C_{14-22}$ 알코올 및 베헤닐알코올로 구성된 액정에멀젼을 제조하고 다양한 분석장비를 이용하여 구조분석을 실시하였다. 먼저 제조한 액정에멀젼을 편광현미경과 cryo-SEM을 이용하여 각각 액정에멀젼의 특징인 maltese cross 무늬와 다층 구조를 확인하였다. 또한, DSC를 이용하여 액정상 형성을 확인하였고, small angle x-ray scattering (SAXS) 분석을 통하여 약 $305{\AA}$의 층간 간격을 갖는 다층 라멜라 구조를 확인하였다. 한편, wide angle x-ray scattering (WAXS) 분석을 통해 제조된 액정에멀젼의 라멜라 구조를 이루고 있는 알킬 사슬 간 배열이 사방정계 구조로 되어 있음을 확인할 수 있었다. 액정에멀젼 구조 연구를 통해 얻어진 다양한 물성 정보는 향후 산업적으로 많이 이용될 것으로 기대된다.

• 분석과학
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• 제20권5호
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• pp.448-451
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• 2007

A new bis(dicyclohexylammonium) chromate dihydrate complex, $[(C_6H_{11})_2NH_2]_2[CrO_4]{\cdot}2H_2O$, (I), has been synthesized and its structure analyzed by FT-IR, EDS, elemental analysis, ICP-AES, and single crystal X-ray diffraction methods. The Cr(VI) complex (I) is tetragonal system, I${\bar{4}}$2d space group with a = 12.5196(1), b = 12.5196(1), c = $17.3796(3){\AA}$, a = ${\beta}$ = ${\gamma}$ = $90^{\circ}$, V = $2724.09(6){\AA}^3$, Z = 4. The crystal structure of complex (I) consists of tetrahedral chromate $[CrO_4]^{2-}$ anion, two organic dicyclohexylammonium $[(C_6H_{11})_2NH_2]^+$ cations and two lattice water molecules. The chromate anion and protonated dicyclohexylammonium cation is mainly constructed through the ionic bond. The cyclohexylammonium rings of the dicyclohexylammonium cation take the chair form and vertical configuration with each other. The N-H${\cdot}$O and O-H${\cdot}$O hydrogen bond networks between the $N_{dicyclohexylammonium}$, $O_{water}$ and $O_{chromate}$ atom lead to self-assembled molecular conformation and stabilize the crystal structure.

• Molecules and Cells
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• 제45권7호
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• pp.495-501
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• 2022

Leucine dehydrogenase (LDH, EC 1.4.1.9) catalyzes the reversible deamination of branched-chain L-amino acids to their corresponding keto acids using NAD⁺ as a cofactor. LDH generally adopts an octameric structure with D4 symmetry, generating a molecular mass of approximately 400 kDa. Here, the crystal structure of the LDH from Pseudomonas aeruginosa (Pa-LDH) was determined at 2.5 Å resolution. Interestingly, the crystal structure shows that the enzyme exists as a dimer with C2 symmetry in a crystal lattice. The dimeric structure was also observed in solution using multiangle light scattering coupled with size-exclusion chromatography. The enzyme assay revealed that the specific activity was maximal at 60℃ and pH 8.5. The kinetic parameters for three different amino acid and the cofactor (NAD⁺) were determined. The crystal structure represents that the subunit has more compact structure than homologs' structure. In addition, the crystal structure along with sequence alignments indicates a set of non-conserved arginine residues which are important in stability. Subsequent mutation analysis for those residues revealed that the enzyme activity reduced to one third of the wild type. These results provide structural and biochemical insights for its future studies on its application for industrial purposes.

• Journal of Radiation Protection and Research
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• 제34권2호
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• pp.65-68
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• 2009

Metal-semiconductor contact is very important for the operating property of semiconductor detector. $Cd_{0.96}$ $Zn_{0.04}$ Te semiconductor crystal was grown with Bridgman method, and the crystal was cut and polished. EPMA (Electron Probe Micro Analyzer) and ICP-MS (Inductively Coupled Plasma Mass Spectrometry) analysis were done to obtain the chemical composition and impurity of the crystal. Metal contact was deposited with thermal evaporator on both sides of the crystal. Detectors with Au/CZT/Au and In/CZT/Au structure were made, and I-V curve and the energy spectrum were measured with the detectors. It could be seen that the detector with the In/CZT/Au structure has superior property than the detector with Au/CZT/Au structure when the crystal resistivity was low. However, the metal contact structure effect becomes low when the crystal resistivity was high.

• 대한화학회지
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• 제57권3호
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• pp.352-356
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• 2013

In this work, a new cadmium complex $[Cd(L)(CH_3COO)_2].2H_2O$ (1) with the ligand L, N,N'-bis(2-pyridinecarboxalidene)-1,2-cyclohexanediamine was prepared and identified by elemental analysis, FT-IR, Raman, $^1H$ NMR spectroscopy and single-crystal X-ray diffraction. The cadmium atom in the crystal structure of 1 has distorted triangular dodecahedral geometry by coordination of the four nitrogen atoms of L and four oxygen atoms of the two acetate ions. Two water molecules are also incorporated in the crystal network. The $O-H{\cdots}O$ hydrogen bonds present in the crystal structure of 1. In this work, three structural surveys including coordination numbers of the cadmium atom, coordination modes of L and resonance in pyridine-2-ylmethanimine-based compounds are presented.

• Bulletin of the Korean Chemical Society
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• 제30권11호
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• pp.2608-2612
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• 2009

The unequivocal solid-state structure and stereochemistry of the hetaryl leuco-TAM dye, 2,2’-(2-phenyl propane- 1,3-diylidene) bis(1,3,3- trimethylindoline) derivatives were established using X-ray single crystal analysis. The X-ray crystal analysis showed that the (Z, E)-isomers only formed stereoselectively, with a so-called “threebladed propeller” conformation, from the reaction of a Fischer base and benzaldehyde derivatives. These isomers were stacked in a juxtaposition to form a dimer or a double dimer, adopting either a triclinic, with P-1, or monoclinic crystal system with a space group P21/n in the unit cell of the crystal.

• 한국잠사곤충학회지
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• 제39권1호
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• pp.67-72
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• 1997

As a condition for obtaining the silk I type crystal that has stability and high reproducibility, after dissolving silk fibroin crystalline part (Fcp), the changes of recrystallized crystal structure according to dialytic pH were examined by x-ray diffraction and differential thermal analysis. The Fcp was obtained from the aqueous solution of silk fibroin enzymatic proteolyzed by chymotrypsin. The crystal structure of Fcp showed silk II type. When the Fcp was dissolved by 10M LiBr aqueous solution, the Fcp1 showed the silk II type at pH 9. However, besides the silk II type, the silk I type structure begins to appear at pH 8 and only the silk I type structure was found below pH 6. On the other hand, the Fcp2 that calcium chloride was used in the dissolution found only the silk I type crystal structure below pH8.

• 통합자연과학논문집
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• 제8권4호
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• pp.250-257
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• 2015

The crystal structure of the potential active 3-(4-ethylphenyl)-3H-chromeno[4,3-c]isoxazole-3a(4H)-carbonitrile ($C_{19}H_{16}N_2O_2$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group $P2_1/c$ with unit cell dimension a=6.6869 (8) ${\AA}$, b=15.8326 (19) ${\AA}$ and c= 15.237 (2) ${\AA}$ [${\alpha}=90^{\circ}$, ${\beta}=100.663^{\circ}$ and ${\gamma}=90^{\circ}$]. In the structure chromene, isoxazole and carboxylate are almost coplanar each other. All geometrical parameters revelled that chromene ring of pyran ring adopt sofa conformation. The crystal packing is stabilized by intermolecular C-H...N and C-H...O hydrogen bond interaction.

• 통합자연과학논문집
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• 제8권3호
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• pp.184-191
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• 2015

The crystal structure of the potential active methyl-3-phenyl-3H-chromeno[4,3-c]isoxazole-3a(4H)-carboxylate ($C_{18}H_{15}NO_4$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the orthorombic space group $P2_12_12_1$ with unit cell dimension $a=9.8320(17){\AA}$, $b=9.9890(18){\AA}$ and $c=15.588(3){\AA}$ [${\alpha}=90^{\circ}$, ${\beta}=90^{\circ}$ and ${\gamma}=90^{\circ}$]. In the structure chromene, isoxazole and carboxylate are almost coplanar each other. All geometrical parameters revelled that chromene ring of pyran ring adopt sofa conformation. The crystal packing is stabilized by intermolecular C-H...O and C-H...N hydrogen bond interaction.