• Bulletin of the Korean Chemical Society
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• 제22권12호
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• pp.1350-1360
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• 2001

The synthesis and characterization of very stable Pd(Ⅱ) η1-imine complexes of bis(3,4-dialkyloxybenzylidene-3', 4'-dialkyloxyaniline)dichloropalladium(Ⅱ) with alkyl chain of hexyl (8), octyl (9), decyl (10) and dodecyl (11) groups, a nd of bis(4-ethyloxybenzylidene-4'-ethyloxyaniline)dichloropalladium(Ⅱ) as a model complex are described. The molecular structure with twisted board-like geometry of the complex resulting from the coordination of Pd(Ⅱ) with η1-imine bonding was confirmed by X-ray crystallographic analysis of the model complex. In contrast to the imine ligands, all the complexes with an exception of 11 display a thermally stable monotropic smectic A mesophase without any decomposition of the complex. These results, characterized by a combination of differential scanning calorimetry, optical polarized microscopy, and powder X-ray scattering experiments, are discussed.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.170-171
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• 2019

When the cement paste in concrete is exposed to high temperatures, the mechanical performance decreases due to a series of reactions inside the cement. In this study, we investigated the change of nanostructure of $C_3S$ when $C_3S$ was exposed to high temperature using pair distribution function (PDF) based on high energy X-ray scattering. As a result of X-ray diffraction, there was no significant difference when $C_3S$ was heated at $300^{\circ}C$, but most of $Ca(OH)_2$ was decomposed into CaO at $500^{\circ}C$. In addition, it was confirmed that CaO is dominant in the nanostructure when $C_3S$ is heated to $500^{\circ}C$.

• 한국세라믹학회지
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• 제34권8호
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• pp.897-907
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• 1997

Thin films of Bi4-xSmxTi3O12(0$\leq$x$\leq$2) were prepared on Pt/Ti/SiO2/Si(100) at $700^{\circ}C$ using spin-coating with sols derived from Bi-Sm-Ti complex alkoxides. From X-ray diffraction analysis, it was observed that Sm-substituted phases resembled ferroelectric Bi4Ti3O12 in structure. Variations of their lattice parameters depending on the amount of Sm-substitution showed that an anomalous structural distortion might exist at x=1. The grain sizes of the thin films decreased from 0.115 ${\mu}{\textrm}{m}$ to 0.078${\mu}{\textrm}{m}$ with increasing the amount of Sm-substitution. The dielectric constants and the remanent polarizations of the thin films decreased with increasing the amount of the Sm-substitution, which were related to decrease of the stereo-active Bi3+ ion contributing to polarization. However, these values were exceptionally high at x=1, compared to those of the other substituted phases. Such an anomaly suggests that the phase of x=1 has 1:1 chemical ordering between Sm and Bi in structure. The thin films of all compositions except x=2 showed ferroelectricity. The thin film of x=2 was paraelectric, whose grains were too fine to exhibit ferroelectricity.

• 한국광물학회지
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• 제26권1호
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• pp.27-34
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• 2013

X-선회절 분석은 결정질 물질의 정량과 정성분석을 위한 가장 효과적인 분석기술이며, 따라서 회절자료를 이용한 매우 다양한 광물조성 정량분석법이 존재한다. 본 연구에서는 비정질 실리카, 석영, 뮬라이트, 강옥으로 제조한 인공광물혼합시료를 대상으로 리트벨트법과 PONKCS (partial or no known crystal structure) 방법을 적용하여 정량 X-선회절 분석을 수행하였다. 100% 비정질 실리카와 내부표준시료 첨가 시료의 회절자료를 이용하여 PONKCS 방법으로 비정질 실리카의 결정 모형을 성공적으로 구축하였다. 비정질 실리카의 경우, 원 중량 대비 치우침의 절대값 평균은 1.85 wt%였다. 비정질 실리카의 함량이 작은 경우 상대적으로 높은 치우침을 보이는데, 이는 배경 회절패턴의 강도가 낮음에 기인하는 것으로 판단된다. 그밖에 석영, 뮬라이트, 강옥의 경우, 치우침의 절대값 평균은 각각 0.53 wt%, 0.87 wt%, 0.57 wt%였다. 내부표준물질 혼합법을 적용한 전통적인 리트벨트 정량분석 결과와 비교할 때 PONKCS 방법이 비정질 실리카를 포함한 인공광물혼합시료에 대하여 신뢰도 높고 성공적인 정량 분석법임을 확인해 주었다.

• Journal of the Korean Wood Science and Technology
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• 제35권3호
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• pp.45-52
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• 2007

굴참나무 목재를 $310{\sim}350^{\circ}C$의 온도조건에서 탄화하여 탄화목재의 해부학적 특성, 중량감소율 및 체적변화를 조사하였다. 그 결과, 시료의 부피는 탄화온도가 높아질수록 감소하였고, 방사 방향으로 할렬이 발생하였다. 중량감소율은 탄화온도가 높아질수록 증가하였으며, 특히 탄화온도 $330{\sim}340^{\circ}C$에서 급격한 중량감소율을 보여주었다. 도관직경의 수축은 접선방향이 방사방향보다 높게 나타났다. SEM관찰에서 탄화온도가 $320^{\circ}C$ 이하의 경우, 목재 세포벽의 벽층구조를 확인할 수 있었지만, $330^{\circ}C$ 이상에서는 세포벽층이 매끄러운 비결정성 형태를 보여주었다. X선회절 결과, 탄화온도 $340^{\circ}C$까지는 목재 셀룰로오스의 결정구조가 남아있었으나, $350^{\circ}C$ 이상에서는 비결정성 구조로 변화된 것이 관찰되었다. 따라서, 목재성분이 탄소로 변화하는 탄화온도는 $350^{\circ}C$ 부근으로 생각되었다.

• 한국세라믹학회지
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• 제53권5호
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• pp.568-573
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• 2016

We explore the crystalline structure and phase transition of lithium thiophosphate ($Li_7P_3S_{11}$) solid electrolyte using electron microscopy and X-ray diffraction. The glass-like $Li_7P_3S_{11}$ powder is prepared by the high-energy mechanical milling process. According to the energy dispersive X-ray spectroscopy (EDS) and selected area diffraction (SAD) analysis, the glass powder shows chemical homogeneity without noticeable contrast variation at any specific spot in the specimen and amorphous SAD ring patterns. Upon heating up to $260^{\circ}C$ the glass $Li_7P_3S_{11}$ powder becomes crystallized, clearly representing crystal plane diffraction contrast in the high-resolution transmission electron microscopy image. We further confirm that each diffraction spot precisely corresponds to the diffraction from a particular $Li_7P_3S_{11}$ crystallographic structure, which is also in good agreement with the previous X-ray diffraction results. We expect that the microscopic analysis with EDS and SAD patterns would permit a new approach to study in the atomic scale of other lithium ion conducting sulfides.

• 한국잠사곤충학회지
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• 제39권1호
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• pp.73-78
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• 1997

분자량 약 7000의 Fcp는 효소분해역반응을 이용하는 것에 의해 분자량 약 17000과 약 24000까지 고분자량화된 PIFcp가 얻어졌다. 또, 효소분해의 역반응에 의해 고분자량화되는 것은 일부의 Fcp이며 Silk II형결정으로부터 Silk I형결정으로 전이하는 것은 대부분의 Fcp에서 나타났다. 이 PIFcp는 X선회절과 시차열분석(DTA)의 결과로부터 어느정도 안정한 Silk I형의 결정구조를 가지는 것이 확인되었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.877-881
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• 2005

In this paper, a novel method for analyzing a textile fabric structure is proposed to segment each yarn of the textile fabric from voxel data made out of its X-ray computed tomography (CT) images. In order to segment the each yarn, directions of fibers, of which yarn consists, are firstly estimated by correlating the voxel with a fiber model. Second, each fiber is reconstructed by clustering the voxel of the fiber using the estimated fiber direction as a similarity. Then, each yarn is reconstructed by clustering the reconstructed fibers using a distance which is newly defined as a dissimilarity. Consequently, each yarn of the textile fabric is segmented from the voxel data. The effectiveness of the proposed method is confirmed by experimentally applying the method to voxel data of a sample plain woven fabric, which is made of polyester two folded yarn. The each two folded yarn is correctly segmented by the proposed method.

• Bulletin of the Korean Chemical Society
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• 제30권5호
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• pp.1021-1025
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• 2009

A novel supramolecular network containing binuclear copper unit $[Cu(phen)_{2}({\mu}-ID\;A)Cu(phen){\cdot}(NO_{3})](NO_{3}){\cdot}4(H_{2}O)$ (1) was synthesized through the self-assembly of iminodiacetic acid ($H_2IDA$) and 1,10-phenanthroline (phen) in the condition of pH = 6. It has been characterized by the infrared (IR) spectroscopy, elemental analysis, single crystal X-ray diffraction, and thermogravimetric analysis (TGA). 1 shows a 2-D supramolecular structure assembled through strong and unique $\pi-\pi$ packing interactions. Density functional theory (DFT) calculations show that theoretical optimized structures can well reproduce the experimental structure. The TGA and powder X-ray diffraction (PXRD) curves indicate that the complex 1 can maintain the structural integrity even at the loss of free water molecules. The magnetic property is also reported in this paper.

• Biodesign
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• 제6권4호
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• pp.100-102
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• 2018

Autophagy is a degradation pathway that targets many cellular components and plays a particularly important role in protein degradation and recycling. This process is very complex and several proteins participate in this process. One of them, P62/SQSTM1, is related to the N-end rule and induces protein degradation through autophagy. The P62/SQSTM1 makes a huge oligomer, and this oligomerization is known to play an important role in its mechanism. This oligomerization takes two steps. First, the PB1 domain of P62/SQSTM1 makes the base oligomer, and then, when the ligand binds to the ZZ domain of P62/SQSTM1, it induces a higher oligomer by the disulfide bond of the two cysteines. To understand the oligomerization mechanism of P62/SQSTM1, we need to know the dimerization of the PB1 domain. In this study, crystals of PB1 dimer were made and the crystals were diffracted by X-ray to collect usable data up to 3.2A. We are analyzing the structure using the molecular replacement (MR) method.