• International Journal of Vascular Biomedical Engineering
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• v.4 no.1
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• pp.17-26
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• 2006

Diabetes mellitus (DM) is a metabolic disorder, characterized by varying or persistent hyperglycemia, which induces several changes in the erythrocyte membrane and its cytoplasm, leading to alteration in the deformability. Techniques applied to measure this are based on filtration of erythrocyte suspension through a membrane and to obtain diffraction pattern under sheared conditions. Ektacytometry requiring less quantity of blood with disposable flow chamber used to measure the deformability of erythrocytes obtained from patients with diabetes and also associated with nephropathy and retinopathy. A decreasing trend of deformability in these patients is observed. The shape parameter form factor, as determined by image processing procedure, increases with the increased of blood glucose levels and shows a pattern similar to filtration time of erythrocyte suspensions through cellulose membranes. Further work is suggested to detect micro-level changes in cell membrane in diabetic patients

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.6 no.3
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• pp.293-300
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• 1996

A continuous growth method (Orr's method) were developed to grow LiNbO3 single crystals. The optimum growth condition established are as follows; When the controlled temperature of a platinum crucible were 1190℃∼1210℃, the pulling rate was 2 mm/hr, the feeding rate was 1.5∼2.5 g/hr, and the rotation speed was 20 rpm. The phase and growth orientation of the grown LiNbO3 crystals wer characterized by a X-ray diffraction method. The overflowing phenomena, which induced cracking into the grown crystal during the process, was effectively suppressed by the control of the growth parameter.

• 한국전산유체공학회:학술대회논문집
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• 2008.03a
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• pp.337-339
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• 2008

As a shock impinges into a vortex of variable strength, complex shock diffraction can occur. Since a vortex has a fixed rotating direction, the shock wave travelling in one direction creates strong asymmetry in the vortex flow field. The process is that first the shock is divided into two parts by the vortex. One part is moving in the adverse direction opposite to the vortex flow which is captured by the vortex center. The other part is moving in the favorable direction, namely, in the direction same as the vortex flow; it is swung around the vortex, accelerating the vortex flow. In this paper we have investigated numerically using ENO scheme how and why the shock-vortex interaction patterns appear so different for different parametric values. Conclusion is that there are three different types of shock-vortex interaction depending on two related parameters: shock Mach number and vortex Mach number. We present a parameter map by which we can discern what type of interaction pattern appears as a shock impinges into a vortex.

• 한국전산유체공학회:학술대회논문집
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• 2008.10a
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• pp.337-339
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• 2008

Abstract: As a shock impinges into a vortex of variable strength, complex shock diffraction can occur. Since a vortex has a fixed rotating direction, the shock wave travelling in one direction creates strong asymmetry in the vortex flow field. The process is that first the shock is divided into two parts by the vortex. One part is moving in the adverse direction opposite to the vortex flow which is captured by the vortex center. The other part is moving in the favorable direction, namely, in the direction same as the vortex flow; it is swung around the vortex, accelerating the vortex flow. In this paper we have investigated numerically using ENO scheme how and why the shock-vortex interaction patterns appear so different for different parametric values. Conclusion is that there are three different types of shock-vortex interaction depending on two related parameters: shock Mach number and vortex Mach number. We present a parameter map by which we can discern what type of interaction pattern appears as a shock impinges into a vortex.

• The Journal of Advanced Prosthodontics
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• v.12 no.1
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• pp.9-14
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• 2020

PURPOSE. The aim of this study was to investigate the effect of different numbers of heat treatments applied to superstructure porcelain on optical, thermal, and phase formation properties of zirconia. MATERIALS AND METHODS. Forty zirconia specimens were prepared in the form of rectangular prism. Specimens were divided into four groups (n = 10) according to the number of firing at heating values of porcelain. Color differences and translucency parameter were measured, and X-ray diffraction (XRD) analysis and differential scanning calorimetry (DSC) were performed. Data were analyzed with analysis of variance (ANOVA). RESULTS. There were no statistically significant differences in ∆E, TP, L, a, and b value changes of the zirconia specimens as a result of repetitive firing processes (P>.05). CONCLUSION. Although additional firing processes up to 4 increase peak density in thermal analysis, additional firing processes up to 4 times can be applied safely as they do not result in a change in color and phase character of zircon frameworks.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.2 no.2
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• pp.96-103
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• 1990

A local Iribarren number is suggested for the universal use of breaker type classification, which relates the bed slope to the wave steepness, both being given from the breaking point. The existing Iribarren number uses the wave length at an offshore point, while the local Iribarren number uses the wave length at the breaking point so that it can imply any influences due to current interaction and diffraction. The modified form of Miche's breaking criterion includes 고 breaking parameter which may be related to the local Iribarren number. Using the modifiedform of Miche's criterion with the local Iribarren number, the inclusion of Doppler effect seems to describe well the wave breaking mechanism in a current-interacted flow on a sloping beach without any additional effects implemented.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.34-35
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• 2014

탄소는 부식되지 않고 친환경적이며 물리화학적 안정성 및 내마모성 등 많은 장점을 가지고 있어 많은 연구들이 진행 되고 있다. 하지만 탄소 박막은 전도도가 낮은 단점을 가지고 있다. 본 연구에서는 탄소 박막의 전도성과 플라즈마 변수와의 상관관계를 규명 하고자 하였다. 박막의 특성은 X-ray Diffraction (XRD), Hall measurement, Contact angle, Raman spectroscopy 등의 분석기기를 사용하여 측정하였고 그 결과 DC보다 Pulse DC를 사용할 때 더 좋은 전기적 특성을 나타내었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.369-372
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• 1996

We prepared LiMn$_2$O$_4$ by reacting stoichiometric mixture of LiOH.$H_2O$ and MnO$_2$ (mole ratio 1 : 1) and heating at 80$0^{\circ}C$ for 24h, 36h, 48h, 60h and 70h. We obtained through X-ray diffraction that lattice parameter varied as function of heat treatment time. heated cathode active materials at 80$0^{\circ}C$ for 36h, (111)/(311) peak ratio was 0.37. It expected good charge/discharge characteristics. When (111)/(311) peak ratio was 0.37, it will be that crystal structure is farmed very well. In the result of charge/discharge test When heated at 80$0^{\circ}C$ for 36h, charge/discharge characteristic of LiMn$_2$O$_4$is the most property. It agree with our expectation.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.7
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• pp.131-138
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• 2008

The microstructural effects on the ultrasonic nonlinearity were investigated in isothermally degraded ferritic 2.25Cr-1Mo steel and low cycle fatigued copper. The variation in ultrasonic nonlinearity (${\beta}/{\beta}_0$) was interpreted as resulting from microstructural changes supported by the electron microscopy and X-ray diffraction, in addition to the mechanical test (Victor's hardness and ductile-brittle transition temperature). The ultrasonic nonlinearity of 2.25Cr-1Mo steel increased abruptly in the initial 1,000 h of degradation, and then changed little due to the coarsening of carbide and precipitation of stable $M_6C$ carbide during isothermal degradation. The ultrasonic nonlinearity of copper increased with the fatigue cycles due to the evolution of dislocation cell substructure.

• Journal of Magnetics
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• v.14 no.2
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• pp.93-96
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• 2009

The Mn-substituted M-type Ba-ferrite ($BaFe_{12-x}Mn_xO_{19}$; x = 0, 2, 4, 6) powders were prepared by the HTTD (High Temperature Thermal Decomposition) method. The effect of $Mn^{3+}$ Jahn-Teller ions on the magnetic properties has been studied by x-ray diffraction, vibrating sample magnetometry, and $M{\ddot{o}}ssbauer$ spectroscopy. With increasing Mn substitution, the lattice parameter $a_0$ increases while $c_0$ decreases. The magnetocrystalline anisotropy constants ($K_1$) were determined as 2.9, 2.2, 1.8, and, $1.3{\times}10^6\;erg/cm^3$ for x = 0, 2, 4, and 6, respectively, by the LAS method. We have studied the change of cation distribution by $M{\ddot{o}}ssbauer$ spectroscopy which is closely related to $K_1$.