• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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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%.

• 에너지공학
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• 제23권3호
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• pp.13-16
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• 2014

무기단결정을 광 펄스로 여기 한 격자에서 광학이나 음향포논을 이용하여 광 여기 반도체가 서브피코초로 관측하고 있다. 다수의 회절 점으로 결정구조를 파악하는 것으로써 광 여기에 의한 분자결정 구조변화를 관측하는 것이 보고되고 있고 또한 반응이 진행되고 있는 중에 분자구조를 하나하나 영상으로 관측하는 것이 연구되고 있다. 단백질 분자구조의 시간에 따른 변화와 용액 중 분자의 광반응에 따른 구조변화를 파악하고 있는데 이것은 시스템에 따라 펨토 초에서 초 단위까지 다양하고 광범위하게 고도의 시간분해능으로 계측할 수 있는 X선 측정기술이다.

• 대한기계학회논문집A
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• 제26권8호
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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.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 추계학술대회 논문집
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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.

• Fibers and Polymers
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• 제6권3호
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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.

• 한국정밀공학회지
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• 제25권7호
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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.

• Bulletin of the Korean Chemical Society
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• 제34권8호
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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.

• Tribology and Lubricants
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• 제18권3호
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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.

• 한국광물학회지
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• 제16권1호
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• pp.65-73
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• 2003

이 연구에서는 X-선 회절법으로 측정한 수소결합의 거리를 보정하는 두 가지 방법을 제시하였다 O…O 거리가 2.5 $\AA$ 이상인 수소결합의 경우는 저온에서 측정한 중성자 회절에 의한 수소결합 데이터를 이용하여 얻은 최적화 곡선 식 d(O-H)=exp((2.173-d(O…O))/0.138)+0.958을 이용하여 수소결합 거리를 보정한다. O…O 거리가 2.5 $\AA$ 이하의 짧은 수소결합의 경우는 결합원자가 최적화 방법(valence-least-squares)을 이용하는 것이 효과적이다. X-선 회절분석으로 얻은 긴 O…O 거리를 갖는 분자간 수소결합의 경우는 수소결합의 거리보정을 해주어야 한다.

• 광물과 암석
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• 제35권4호
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• pp.431-445
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• 2022

점토질 암석의 광물함량을 효과적이고 실용적으로 분석하는 방법을 X-선 분말회절분석 실험을 통하여 연구하였다. 점토질 암석의 X-선 분말회절 정량분석을 위해서는 측면마운팅(side mounting) 방법에 의한 무작위 배향(random orientation)의 전암(whole-rock) 분말시료의 준비가 필요하다. 또한, 암석을 구성하고 있는 점토광물의 감정을 위하여 2 ㎛ 이하 점토입도의 배향성 마운트(oriented mount)시편의 준비와 에틸렌글리콜 처리, 열처리 등의 실험과정이 요구된다. 정량분석을 위하여 RIR(reference intensity ratio)방법과 리트벨트(Rietveld) 회절도 계산 방법을 사용하였다. RIR값을 사용하여 전암 X-선 회절도로부터 총 점토 함량과 비점토광물(non-clay minerals)들의 함량을 얻을 수가 있었다. 또한, 점토입도의 배향성 X-선 회절도로부터는 각각 점토광물의 상대함량을 계산하여 이를 총 점토광물에 할당할 수가 있었다. 전암 X-선 회절의 리트벨트 방법에서는 10°(2θ) 미만의 X-선 회절 영역은 제외한 후에 리트벨트 회절도를 계산하였을 때 효과적인 정량분석 값을 얻을 수 있었다. 분석결과는 RIR방법과 리트벨트 방법이 서로 근사한 정량분석 값을 보여주었다. 따라서, 연구결과는 실험실에서의 일상적인 점토질암의 광물정량분석을 성공적으로 수행하는 것이 가능함을 지시한다. 그러나, 점토광물은 화학적 및 구조적 특정이 다른 수많은 변종이 존재하기 때문에 점토질암의 정량분석은 아직도 도전해야 하는 과제이다.