• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.6
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• pp.616-621
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• 2003

There are various Non-Destructive Evaluation (NDE) techniques used for measurement of residual stresses in material, such as magnetic methods, X-ray diffraction, Ultrasonic velocity measurement etc. The capabilities, applications and limitations of these techniques for evaluation of cold work/plastic deformation were studied and compared. Mild steel plates were subjected to different degree of cold deformation and were analyzed by Magneto-mechanical Acoustic Emission (MAE), Barkhausen Noise (BN) and magnetic properties (hysteresis loop parameters analysis). Further, these specimens were analyzed by X-ray diffraction and ultrasonic velocity measurements. The microhardness measurement and microstructure studies of these cold worked plates were also carried out. The results of all these studies and comparison of different techniques are discussed in this paper.

• Journal of Life Science
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• v.8 no.4
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• pp.373-380
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• 1998

A considerable change observed in X-ray diffraction during the muscle contraction was that the movement of myosin head and conformational change of contractile monecules were occurred in the muscle contraction. Time slice requires tension peak after the onset of stimulation and the height of tension peak depends on the number of twitch cycle. The intensity of I$_{11}$, I$_{10}$, 143${\AA}$ reflection is measured with 5ms time resolution and is recorded in isometric tension. The peak height of I$_{11}$ and 143${\AA}$ intensity is changed after the onset of a stimulation I$_{i}$, and the length of twitch is shortened by successive twitches in the case of stimulation TI$_{i}$. On the other hand, the peak height of I$_{11}$ and 215${\AA}$ intensity starts to decrease at the 1st twitch and remains constant at low peak hight without appreciable recovery during the contraction term. In the case of uccessive twitch stimulation, the myosin heads of muscle are once moved from their resting position and never returned to their initial position.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.731-734
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• 2005

Cut slopes are collapsed in Korea every year. Cut slope collapses cause a loss of lives and assets. Many researchers make clear collapse factor of cut lope. Fresh rock weathered through reaction undergroundwater and groundwater. During weathering process, weathered minerals are created. Weathered minerals are analysed by X-ray diffraction meter. X-ray diffraction meter make possible quantity assessment of degree of weathering and indicator of potential collapse possibilities. This paper discuss possibilities of cut slope dangerous with analysis of weathered minerals of cut slope.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.7
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• pp.1664-1673
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• 1994

As a fundamental study on effects of thermal-cycles on residual stress of ceramics/metal joints, residual stresses in $Si_3N_4$/SUS304 joint specimens were measured before and single thermal-cycle by X-ray diffraction method and finite element method(FEM). The residual stress was found to increase after single thermal-cycle, which was agreeable with the results of residual stress measurement by X-ray diffraction method and residual stress analysis by finite element method. After the residual stress measurement, 4-point bending tests were performed. The relationship between the bending strength, the thermal-cycle temperature and hold time was examined. The bending strength was found to decrease with the increase of residual stress in linear relation.

• Journal of the Korean Ceramic Society
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• v.44 no.4 s.299
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• pp.224-229
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• 2007

To evaluate the cooling rate of clinker quantitatively, several clinkers with different cooling rate were made in the laboratory. The X-ray diffraction pattern of Ferrite 002 reflection were measured and the parameters were calculated by using split type pseudo-Voigt function. The X-ray diffraction patterns of the Ferrite phase in the clinkers from cement manufacturing plant were analyzed by using the parameters and the analysis program was developed to calculate the cooling rate quantitatively. The cooling rate coefficients of the clinkers were calculated by using the profile fitting method of the program and the influence of cooling rate on strength was evaluated. The results show that there is a close relation between the cooling rate of clinker and the strength of cement.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.591-596
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• 2001

The purpose of this study is to examine the change of half value breadth and residual stress during fatigue process in S45C Steel by X-ray diffraction. For S45C Steel, the relationship between the change in fatigue damage of the specimen and the half value breadth, and residual stress of X-ray diffraction profiles during the fatigue processes has been investigated. The half value breadth(HVB) decreases in he early period of fatigue cycle. The change of HVB is relation to cyclic work hardening. In $10{\sim}20%$ of ratio of fatigue life, the change in the half value breadth is not marked. During fatigue process, the residual stress is changed with fatigue cycle increasing.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.149-149
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• 2011

CdS films were deposited on glass substrates by R.F. magnetron sputtering method and the films were annealed at various substrate temperatures ranging from room temperature to $300^{\circ}C$. Structural properties of the films were studied by X-ray diffraction analysis. The structural parameters as crystallite size have been evaluated. The crystallite sizes were found to increase, and the X-ray diffraction patterns were seen to sharpen by increasing substrate temperatures. X-ray diffraction patterns of these films indicated that they contain both cubic (zincblende) and hexagonal (wurtzite) structures as a mixture. Optical properties of the films were measured at room temperature by using UV/VIS spectrometer in the wavelength range of 190 to 1100nm and optical absorption coefficients were calculated using these data. The energy gap of the films was found to decrease, and the band edge sharpness of the optical absorption was seen to oscillate by annealing. The results show that heat treatments under optimal annealing condition can provide significant improvements in the properties of CdS thin films.

• The Korean Journal of Ceramics
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• v.6 no.3
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• pp.236-239
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• 2000

Both the X-ray diffraction data of the normal direction in the sample orientation and the pole figure data of three reflections, (111), (200) and (220), were used to do the Rietveld refinement for the copper sheet prepared by a cold rolling process. The agreement between calculated and observed patterns was not satisfactory, which was attributed to the preferred orientation effect of the copper sheet. The Rietveld refinement for the copper sheet could be done successfully by applying the pole density of each reflection obtained from the corresponding inverse pole figure to the X-ray diffraction data of the normal direction. The R-weighted pattern, $R_{wp}$ was 12.99% and the goodness-of-fit indicator, S, was 3.68.

• Journal of the Korean Chemical Society
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• v.7 no.2
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• pp.182-185
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• 1963

In the previous paper of the series of researches on the graphitic properties of anthracites, authors have already reported the results on the electrical specific resistance measurements for Korean anthracites in order to develope a simple methods which differentiate graphite from anthracite. In this paper, the X-ray diffraction method and oxidation have been applied and compared with the results which were obtained by the specific resistance measurements in the previous paper. It has been confirmed that there is a parallel relation between the value of specific resistance measurement and height of hexagonal peak by X-ray diffraction, but the color reaction due to graphitic acid by oxidation does not show any definite critical points between graphite and anthracite.

• Journal of the Korean Ceramic Society
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• v.48 no.5
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• pp.458-462
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• 2011

The strength of ceramic was improved by lamination by suppressing the propagation of cracks with compressive residual stress in the face layer of the laminate. Hot pressed SiAlON+SiC/SiC/SiAlON+SiC laminate discs were fabricated for tailored residual stress. The residual stress in this laminate was studied by X-ray diffraction (XRD). There was considerable compressive residual stress in the face layer. A Finite Element Analysis (FEA) was performed to support the measured XRD results and to determine the stress field in the laminate. The residual stress measured by XRD had satisfactory agreement with the analytically calculated and FEA values. The measured value by XRD was -385 ${\pm}$ 20 MPa over most of the face layer. The calculated and FEA values were -386 MPa and -371MPa, respectively. FEA also showed significantly modified stresses and the maximum tensile stress near the edge region which are possible crack generators in the presence of flaws or contact damage.