• Title/Summary/Keyword: X-Ray Diffraction

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The Determination of Glass content in fly Ash by X-Ray Diffraction (분말X선회절법에 의한 플라이 애시의 유리질 정량)

  • 이승헌;김홍주
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.159-162
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    • 2000
  • The purpose of this study is to develope an accurate procedure for measuring the glass content of fly ash produced by bituminous coal to assist in predicting their behavior in concrete. Quantitative mineralogical compositions of fly ashes were obtained by internal standard method using powder X-ray diffraction analysis. In the X-ray diffraction method, the specimen and standard fluorite were cautiously mixed and pulverized to 22$\mu$m in wet process so as to avoid the prefered orientation of the crystal and microabsorption effect of X-ray. calibration curve were fitted for several references peaks of four phases:$\alpha$-quartz. mullite, magnetite, hematite. The amount of glass was calculated by subtracting the amount of crystal phase and loss on ignition from the total amount. Glass content determined with this method ranged from 66.7 to 75.wt%.

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Survey on ultrafast time resolved X-ray diffraction measurements of crystal structure (X선의 초고속 결정구조 측정법)

  • Koo, Y.D.;Kim, Y.C.;Oh, C.S.
    • Journal of Energy Engineering
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    • v.23 no.3
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    • pp.13-16
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    • 2014
  • We have surveyed on significant progress in recent developments of accelerator-based pulsed X-ray sources has offered the opportunity for time-resolved studies on fast structure dynamics on the nanometer scale. The required and currently available techniques for time resolved X-ray diffraction measurements using the third-generation synchrotron radiation sources are summarized. Ultrafast X-ray experimental techniques are discussed for femtosecond studies at future synchrotron radiation sources.

A Study on the Failure Mechanism of Turbine Blade using X-Ray Diffraction and FEM (X선 회절과 유한요소법을 이용한 터빈 블레이드의 파괴기구에 관한 연구)

  • Kim, Seong-Ung;Hong, Sun-Hyeok;Jeon, Hyeong-Yong;Jo, Seok-Su;Ju, Won-Sik
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.8
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    • pp.1645-1652
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    • 2002
  • The failure analysis on fractured parts is divided into the qualitative method by naked eyes and metallurgical microscope etc. and the quantitative method by SEM and X-ray diffraction etc. X-ray fractography can be applied to contaminated surface as well as clean surface and gain the plastic deformation and the residual stress near the fractured surface. Turbine blade is subject to cyclic bending force by steam pressure and suffers fatigue damage according to the increasing operating time. Therefore, to clean up the fracture mechanism of torsion-mounted blade in nuclear plant, the fatigue and the X-ray diffraction test was performed on the 12%Cr steel fur turbine blade and the fractured parts. The correlation of X-ray parameter and fracture mechanics parameter was determined, and then the load applied to actual broken turbine blade was predicted. Failure analysis was performed by contact stress analysis and Goodman diagram of torsion-mounted blade.

Microscopic analysis of gas hydrates using X-ray diffraction method (X-ray diffraction을 이용한 가스 하이드레이트 미세구조 분석)

  • Lee, Jong-Won;Seol, Ji-Woong;Koh, Dong-Yeun;Lee, Huen
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.10a
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    • pp.178-181
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    • 2008
  • 다양한 조성을 갖는 $CH_4+CO_2$ 혼합 기체 하이드레이트 샘플의 미세 구조 분석을 위하여 X-ray 회절 방법을 이용하였다. X-ray 회절 분석을 이용할 경우, 하이드레이트로의 전환율과 같은 정성적인 분석뿐 아니라 각 객체별 cage occupancy와 같은 정량적인 분석까지도 가능한 것으로 나타났다. 또한 이렇게 얻어진 X-ray 회절 분석 결과 및 refinement 결과를 $^{13}C$ 고체 NMR 방법과 교차 비교함으로써 측정 결과의 신뢰도를 높이려 하였다. 얻어진 분석 결과는 이후 가스 하이드레이트를 이용한 다양한 연구 분야에서 저장용량 평가 및 객체 점유율과 같은 미세 구조 정보를 얻는 데에 유용하게 사용될 것으로 전망된다.

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An in Depth Study of Crystallinity, Crystallite Size and Orientation Measurements of a Selection of Poly(Ethylene Terephthalate) Fibers

  • Karacan Ismail
    • Fibers and Polymers
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    • v.6 no.3
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    • pp.186-199
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    • 2005
  • A selection of commercially available poly(ethy1ene terephtha1ate) fibers with different degrees of molecular alignment and crystallinity have been investigated utilizing a wide range of techniques including optical microscopy, infrared spectroscopy together with thermal and wide-angle X-ray diffraction techniques. Annealing experiments showed increased molecular alignment and crystallinity as shown by the increased values of birefringence and melting enthalpies. Crystallinity values determined from thermal analysis, density, unpolarized infrared spectroscopy and X-ray diffraction are compared and discussed in terms of the inherent capabilities and limitations of each measurement technique. The birefringence and refractive index values obtained from optical microscopy are found to decrease with increasing wavelength of light used in the experiments. The wide-angle X-ray diffraction analysis shows that the samples with relatively low orientation possess oriented non-crystalline array of chains whereas those with high molecular orientation possess well defined and oriented crystalline array of chains along the fiber axis direction. X-ray analysis showed increasing crystallite size trend with increasing molecular orientation. SEM images showed micro-cracks on low oriented fiber surfaces becoming smooth on highly oriented fiber surfaces. Excellent bending characteristics were observed with knotted fibers implying relatively easy fabric formation.

The Characteristics of Residual Stresses in the Welded Joint of P92 Steel for Fossil Power Plant by the X-ray Diffraction (X-ray 회절을 이용한 화력발전소용 P92 강 용접부의 잔류응력 특성)

  • Hyun, Jung-Seob;Yoo, Keun-Bong;Choi, Hyun-Sun
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.7
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    • pp.116-123
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    • 2008
  • In the fossil power plant, the reliability of the components which consist of the many welded parts depends on the quality of welding. The residual stress is occurred by the heat flux of high temperature during weld process. This decreases the mechanical properties as the strength of fatigue and fracture or causes the stress corrosion cracking and fatigue fracture. Especially, the accidents due to the residual stress occurred at the weld parts of high-temperature and high-pressure pipes and steam headers. Also, the residual stress of the welded part in the recently constructed power plants has been brought into relief as the cause of various accidents. The aim of this study is the measurement of the residual stress using the x-ray diffraction method. The merits of this are more accurate and applicable than other methods. The materials used for the study is P92 steel for the use of high temperature pipe on super critical condition. The variables of tests are the post-weld heat treatment, the surface roughness and the depth from the original surface. The test results were analyzed by the distributed characteristics of the full width at half maximum intensity (FWHM) in x-ray diffraction intensity curve and by the relation of hardness with FWHM.

Synthesis, Structures and Properties of Two Metal-organic Frameworks Derived from 3-Nitro-1,2-benzenedicarboxylic Acid

  • Xu, Wen-Jia;Zhang, Ling-Yu;Tang, Jin-Niu;Wang, Dai-Yin;Pan, Gang-Hong;Feng, Yu
    • Bulletin of the Korean Chemical Society
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    • v.34 no.8
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    • pp.2375-2380
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    • 2013
  • Two metal-organic frameworks based on the connectivity co-effect between rigid benzenedicarboxylic acid and bridging ligand have been synthesized $[Zn_2(3-NO_2-bdc)_2(4,4'-bpy)_2H_2O]_n$ (1), $[Co(3-NO_2-bdc)(4,4'-bpy)H_2O]_n$ (2) (where $3-NO_2-bdcH_2$ = 3-nitro-1,2-benzenedicarboxylic acid, 4,4'-bpy = 4,4'-bipyridine). The two novel complexes were characterized by IR spectrum, elemental analysis, fluorescent properties, thermogravimetric analysis, single-crystal X-ray diffraction and powder X-ray diffraction (PXRD). X-ray structure analysis reveals that 1 and 2 are two-dimensional (2D) network structures. Complex 1 and complex 2 belong to triclinic crystal with P-1 space group. The luminescence measurements reveal that two complexes exhibit good fluorescent emissions in the solid state at room temperature. Also, thermal decomposition process and powder X-ray diffraction of complexes were investigated.

Discussion on Hardness Measuring of Bearing Steel by X-ray Diffraction (X선회절에 의한 베어링강의 경도측정에 대한 고찰)

  • 이한영
    • Tribology and Lubricants
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    • v.18 no.3
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    • pp.187-193
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    • 2002
  • The half-value breadth off-ray diffraction profile line is generally used for a factor in nondestructive hardness measuring method of steel. In this paper, the problem in using the half-value breadth for the hardness measuring method is evaluated in strain hardened steel. And new hardness measuring method using residual stress is proposed X-ray diffraction test after rolling contact fatigue test of ball bearing with inner race of various hardness are carried out to measure the distribution of residual stress and half-value breadth from surface. The result of this study shows that there is little correlation between half-value breadth and hardness in the higher strength region and in the region increasing the hardness by strain hardening. But the magnitude of residual stress on/under race after rolling contact fatigue test becomes clearly to be correlative with hardness. Thus, it is concluded that the hardness of strain hardened steel can be estimated by this relationship between residual stress and hardness.

Correction Method of the Hydrogen Bond-Distance from X-ray Diffraction: Use of Neutron Data and Bond Valence Method (X-선 회절로 얻은 수소결합의 결합거리 보정 방법: 중성자 회절결과와 결합원자가 방법 이용)

    • Journal of the Mineralogical Society of Korea
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    • v.16 no.1
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    • pp.65-73
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    • 2003
  • In this study we have derived the two correction methods of hydrogen bonding distance. In case of the intermediate or long hydrogen bond(>2.5 $\AA$), hydrogen bonding distances can be corrected by using the function d(O-H)=exp((2.173-d(O…O))/0.138)+0.958 obtained by least- squares fit to the data from the neutron diffraction at low temperatures. The valence-least-squares method is effective for the distance correction of very short hydrogen bond(<2.5 $\AA$). The distance correction is necessary for the long intermolecular hydrogen bond obtained from X-ray diffraction analysis.

A Study of Mineral Quantification on Clay-Rich Rocks (점토질 암석의 광물정량 분석법 연구)

  • Byeong-Kook, Son;Gi-O, An
    • Korean Journal of Mineralogy and Petrology
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    • v.35 no.4
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    • pp.431-445
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    • 2022
  • A quantitative phase analysis method of X-ray powder diffraction was studied to determine the mineral content of clay-rich rocks practically as well as effectively. For quantitative X-ray powder diffraction analysis of the clay-rich rocks, it is necessary to prepare whole-rock powder samples with a random orientation by side mounting method. In addition, for the identification of the clay minerals in the rock, it is required to prepare an oriented mount specimen with a clay particle size of 2 ㎛ or less, ethylene glycol treatment, and heat treatment. RIR (reference intensity ratio) and Rietveld method were used for the quantitative analysis of the clay-rich rocks. It was possible to obtain the total clay and the non-clay minerals contents from the whole-rock X-ray diffraction profiles using the RIR values. In addition, it was possible to calculate the relative content of each clay mineral from the oriented X-ray diffraction profiles of the clay particle size and assign it to the total clay. In the Rietveld method of whole-rock X-ray diffraction, effective quantitative values were obtained from the Rietveld diffraction patterns excluded the region of less than 10 degrees (2θ). Similar quantitative values were shown in not only the RIR but the Rietveld methods. Therefore, the analysis results indicate a possibility of a routine quantitative analysis of clay-rich rocks in the laboratory. However, quantitative analysis of clay minerals is still a challenge because there are numerous varieties of clay minerals with different chemical and structural characteristics.