The Experts below are selected from a list of 339 Experts worldwide ranked by ideXlab platform
Dongkil Choi - One of the best experts on this subject based on the ideXlab platform.
-
the quantitative assessment of the tibia bony surface for Proper Screw insertion angle by re aligning ct coordinate in high tibial osteotomy
Orthopaedic Proceedings, 2018Co-Authors: Dongkil ChoiAbstract:IntroductionOpen wedge high tibial osteotomy (OWHTO) is an operation by the Proper load re-distribution in the treatment for medial uni-compartmental arthritis of the knee joint. However, for the Proper load re-distribution, stable fixation is mandatory. For the stable fixation, plate should be contoured to the bony surface and Screws should be inserted from the central area of the medial side to the hinge area of the lateral side in the proximal fragment because most failures occur at the relatively lesser supported lateral hinge area. Therefore, the purpose of this study was to evaluate the Screw insertion angle and orientation that is inserted to the direction of the lateral hinge with an anatomical plate that is post-contoured with a surface geometry of the proximal tibia after the OWHTO. The hypothesis of this study was that the position and orientation would be different according to the correction degree (median value 10 mm) and surgical technique (uni-planar vs bi-planar).Materials and MethodsThir...
-
the quantitative assessment of the tibia bony surface for Proper Screw insertion angle by re aligning ct coordinate in high tibial osteotomy
Journal of Bone and Joint Surgery-british Volume, 2016Co-Authors: Dongkil ChoiAbstract:Introduction Open wedge high tibial osteotomy (OWHTO) is an operation by the Proper load re-distribution in the treatment for medial uni-compartmental arthritis of the knee joint. However, for the Proper load re-distribution, stable fixation is mandatory. For the stable fixation, plate should be contoured to the bony surface and Screws should be inserted from the central area of the medial side to the hinge area of the lateral side in the proximal fragment because most failures occur at the relatively lesser supported lateral hinge area. Therefore, the purpose of this study was to evaluate the Screw insertion angle and orientation that is inserted to the direction of the lateral hinge with an anatomical plate that is post-contoured with a surface geometry of the proximal tibia after the OWHTO. The hypothesis of this study was that the position and orientation would be different according to the correction degree (median value 10 mm) and surgical technique (uni-planar vs bi-planar). Materials and Methods Thirty-one uni-planar and thirty-eight bi-planar osteotomies were evaluated. Postoperative CT data obtained after OWHTO were used for the 3D reconstruction of the proximal tibia. Anterior dimension (L1) and posterior dimension (L2) of the proximal tibia were measured in sagittal plane from tibial spine. Screw insertion points using four holes were even distributed using L1 and L2 value. As Screw insertion angle was set from four holes to lateral hinge of the ‘Safe Zone’. Those four angles were measured in the axial and coronal plane. These were compared according to the correction degree and surgical technique. Results Anterior AP dimension ‘L19and posterior AP dimension ‘L29were measured 24.0 ± 3.7 mm, 22.6 ± 3.1 mm. Angulations of Screw from respectively Screw hole to lateral hinge were measured 11.3 ± 1.7°, 3.5 ± 1.3°, 3.1 ± 1.5°, and 9.5 ± 1.1° in the axial plane and 81.5 ± 6.0°, 101.5 ± 2.6°, 90.8 ± 3.7°, and 99.2 ± 2.8° in coronal plane, respectively. None of the comparisons were statistically different, regardless of the correction degree and operative technique (Table1). Conclusions Range of Screw angulation showed regular pattern according to the site of the Screw hole and it was not different, regardless of the correction degree and operative technique. This study provided range of the Screw angulation by the anatomical surface modeling. Future study would give additional benefit for the optimal Screw angle and stability such as finite element analysis or other methods.
Zhenfa Zi - One of the best experts on this subject based on the ideXlab platform.
-
Indium doping effect on the magnetic Properties of Y-type hexaferrite Ba 0.5 Sr 1.5 Zn 2 (Fe 1-x In x ) 12 O 22
Current Applied Physics, 2018Co-Authors: Min Zhang, Zhenfa ZiAbstract:Abstract The effect of indium doping on structural and magnetic Properties of Y-type hexaferrite Ba0.5Sr1.5Zn2(Fe1-xInx)12O22 (x = 0, 0.02, 0.04, 0.06, 0.08 and 0.1) prepared by the solid state reaction method was investigated. The Rietveld refinement method was used to analyze the X-ray diffraction patterns. The magnetic transition temperatures associated with the Proper-Screw spin phase to the collinear ferrimagnetic spin phase transition can be efficiently modulated by varying indium content. The magnetic transition temperature increases to a maximum with indium content x = 0.04 and then decreases with x, suggesting the possibility that electrically controlled magnetization reversal can be can be effectively tailored by varying indium content. The saturation magnetization at room temperature was decreased as increasing indium content, which can be explained as the metal ions occupation. It is worthy to note that the coercivity of In-doped samples was decreased drastically compared that of undoped sample, which is probably resulted from the reduction in anisotropy field with substitution of In3+ for Fe3+. The In-doped hexaferrite Ba0.5Sr1.5Zn2(Fe1-xInx)12O22 may be potential candidates for application in magnetoelectric devices.
-
Magnetic Properties and magnetodielectric effect in Y-type hexaferrite Ba0.5Sr1.5Zn2-xMgxFe11AlO22
Journal of Alloys and Compounds, 2017Co-Authors: Min Zhang, Xiangkai Kong, Zhenfa ZiAbstract:Abstract The effect of Mg substitution on structural, magnetic, and dielectric Properties of Y-type hexaferrite Ba 0.5 Sr 1.5 Zn 2- x Mg x Fe 11 AlO 22 ( x = 0, 0.4, 0.8, 1.2, 1.6, 2.0) prepared by the solid state reaction method was investigated. The X-ray diffraction patterns are analyzed by Rietveld refinement method and the hexagonal structure with R 3 − m was confirmed. The magnetic transition temperatures associated with the longitudinal conical to Proper Screw phase transition ( T 1 ) and Proper Screw to ferrimagnetic phase transition ( T 2 ) can be modulated by varying Mg content. For x ≤ 1.2 samples, the transition temperature T 2 monotonically increases with increasing Mg substitution, suggesting the possibility that the helical spin order of Mg substituted Y-type hexaferrites is sustained up to higher temperatures than that of undoped samples. The saturation magnetization at room temperature increases to a maximum with Mg content x = 1.2 and then decreases with x . The variations of magnetic Properties can be attributed to the difference in the preferential site for Zn and Mg and different distribution of Fe 3+ ions over tetrahedral and octahedral sites. The results of magnetic field dependence of dielectric constant, i.e., magnetodielectric effect, at various temperatures imply that the doped samples show magnetically induced ferroelectricity up to 250 K. The intrinsic magnetodielectric effect is observed in all the samples. It is worthy to note that the magnetodielectric effect measured below 200 K increases with increasing Mg content, which is probably attributed to the variation of magnetic structures. The Mg-doped hexaferrites Ba 0.5 Sr 1.5 Zn 2- x Mg x Fe 11 AlO 22 may be potential candidates for application in magnetoelectric devices.
-
Mg doping effect on the magnetic Properties of Y-type hexaferrite Ba0.5Sr1.5Zn2−xMgxFe12O22
Journal of Alloys and Compounds, 2016Co-Authors: Min Zhang, Xiangkai Kong, Zhenfa ZiAbstract:Abstract The microstructure and magnetic Properties of Mg-doped Ba0.5Sr1.5Zn2Fe12O22 hexaferrites synthesized by the solid state method are investigated. All the undoped and doped samples show a sharp Screw Proper spin phase to collinear ferrimagnetic spin phase transition above room temperature, and transition temperature increases distinctly with Mg doping. It is noteworthy that all the samples exhibit another magnetic phase transition at a lower temperature T1, which is associated with the longitudinal conical to the Proper Screw phase transition. The transition temperature T1 can be modulated by varying Mg content, indicating that the longitudinal conical spin phase is stabilized by the Mg-substitution. The saturation magnetization at room temperature increases to a maximum with Mg content x = 0.8 and then decreases with x. The variations of magnetic Properties can be ascribed to the difference in the preferential site for Zn and Mg and different distribution of Fe3+ ions over tetrahedral and octahedral sites. It is worth noting that the range for the intermediate-III phase increases significantly as x increases to 2.0, suggesting that Mg-doped samples may be display field-induced ferroelectric order at temperature close to RT and in wide magnetic-field regions. The room-temperature M-H curves at lower applied field indicate that magnetic-field-induced ferroelectric phase can be stabilized at zero magnetic field by the substitution by Mg2+ for Zn2+. The Mg-doped hexaferrites Ba0.5Sr1.5Zn2Fe12O22 may be potential candidates for applying in magnetoelectric devices.
Akio Fuwa - One of the best experts on this subject based on the ideXlab platform.
-
Mössbauer Study of the Ferroelectric State in Ga-Substituted CuFeO2
Journal of the Physical Society of Japan, 2014Co-Authors: Shin Nakamura, Akio Fuwa, Noriki TeradaAbstract:57Fe Mossbauer spectroscopic measurements have been conducted on CuFe1−xGaxO2 single crystals, in order to investigate the magnetic structures and hyperfine parameters in ferroelectric CuFe0.965Ga0.035O2 and paraelectric CuFeO2. We confirmed that the Mossbauer spectrum at 4.2 K in CuFeO2 is explained by the collinear antiferromagnetic structure with spins along the hexagonal c-axis. In the ferroelectric phase in CuFe0.965Ga0.035O2, the spectrum consists of three magnetic components, where magnetic hyperfine fields distribute in three different directions within the (110) plane. This configuration is not completely consistent with a simple Proper Screw structure with a uniform spin distribution. The quadrupole coupling constants e2qQ/2 are unexpectedly large for both specimens. In the ferroelectric state in CuFe0.965Ga0.035O2, e2qQ/2 becomes noticeably smaller than that in the paraelectric phase in CuFeO2. We discuss the difference in quadrupole coupling constant between the ferroelectric and paraelectric ...
-
Mössbauer study on Y-type hexaferrite Ba_2Mg_2Fe_12O_22
Hyperfine Interactions, 2012Co-Authors: Shin Nakamura, Yorihiko Tsunoda, Akio FuwaAbstract:Mössbauer study on a Y-type hexaferrite Ba_2Mg_2Fe_12O_22 has been conducted by using a single crystal specimen. The spins are in the c-plane down to 60 K. For 18 h _VI site Fe, the quadrupole shifts and the outermost line width change around 195 K, where the transition from ferrimagnetic to Proper Screw spin structure takes place. Below 50 K, the spin reorientation transition to a longitudinal conical structure was also recognized. At 16 K, the spins incline about 15° from the c -plane.
-
Mössbauer study on Y-type hexaferrite Ba 2 Mg 2 Fe 12 O 22
Hyperfine Interactions, 2012Co-Authors: Shin Nakamura, Yorihiko Tsunoda, Akio FuwaAbstract:Mossbauer study on a Y-type hexaferrite Ba2Mg2Fe12O22 has been conducted by using a single crystal specimen. The spins are in the c-plane down to 60 K. For 18h VI site Fe, the quadrupole shifts and the outermost line width change around 195 K, where the transition from ferrimagnetic to Proper Screw spin structure takes place. Below 50 K, the spin reorientation transition to a longitudinal conical structure was also recognized. At 16 K, the spins incline about 15° from the c-plane.
Min Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Indium doping effect on the magnetic Properties of Y-type hexaferrite Ba 0.5 Sr 1.5 Zn 2 (Fe 1-x In x ) 12 O 22
Current Applied Physics, 2018Co-Authors: Min Zhang, Zhenfa ZiAbstract:Abstract The effect of indium doping on structural and magnetic Properties of Y-type hexaferrite Ba0.5Sr1.5Zn2(Fe1-xInx)12O22 (x = 0, 0.02, 0.04, 0.06, 0.08 and 0.1) prepared by the solid state reaction method was investigated. The Rietveld refinement method was used to analyze the X-ray diffraction patterns. The magnetic transition temperatures associated with the Proper-Screw spin phase to the collinear ferrimagnetic spin phase transition can be efficiently modulated by varying indium content. The magnetic transition temperature increases to a maximum with indium content x = 0.04 and then decreases with x, suggesting the possibility that electrically controlled magnetization reversal can be can be effectively tailored by varying indium content. The saturation magnetization at room temperature was decreased as increasing indium content, which can be explained as the metal ions occupation. It is worthy to note that the coercivity of In-doped samples was decreased drastically compared that of undoped sample, which is probably resulted from the reduction in anisotropy field with substitution of In3+ for Fe3+. The In-doped hexaferrite Ba0.5Sr1.5Zn2(Fe1-xInx)12O22 may be potential candidates for application in magnetoelectric devices.
-
Magnetic Properties and magnetodielectric effect in Y-type hexaferrite Ba0.5Sr1.5Zn2-xMgxFe11AlO22
Journal of Alloys and Compounds, 2017Co-Authors: Min Zhang, Xiangkai Kong, Zhenfa ZiAbstract:Abstract The effect of Mg substitution on structural, magnetic, and dielectric Properties of Y-type hexaferrite Ba 0.5 Sr 1.5 Zn 2- x Mg x Fe 11 AlO 22 ( x = 0, 0.4, 0.8, 1.2, 1.6, 2.0) prepared by the solid state reaction method was investigated. The X-ray diffraction patterns are analyzed by Rietveld refinement method and the hexagonal structure with R 3 − m was confirmed. The magnetic transition temperatures associated with the longitudinal conical to Proper Screw phase transition ( T 1 ) and Proper Screw to ferrimagnetic phase transition ( T 2 ) can be modulated by varying Mg content. For x ≤ 1.2 samples, the transition temperature T 2 monotonically increases with increasing Mg substitution, suggesting the possibility that the helical spin order of Mg substituted Y-type hexaferrites is sustained up to higher temperatures than that of undoped samples. The saturation magnetization at room temperature increases to a maximum with Mg content x = 1.2 and then decreases with x . The variations of magnetic Properties can be attributed to the difference in the preferential site for Zn and Mg and different distribution of Fe 3+ ions over tetrahedral and octahedral sites. The results of magnetic field dependence of dielectric constant, i.e., magnetodielectric effect, at various temperatures imply that the doped samples show magnetically induced ferroelectricity up to 250 K. The intrinsic magnetodielectric effect is observed in all the samples. It is worthy to note that the magnetodielectric effect measured below 200 K increases with increasing Mg content, which is probably attributed to the variation of magnetic structures. The Mg-doped hexaferrites Ba 0.5 Sr 1.5 Zn 2- x Mg x Fe 11 AlO 22 may be potential candidates for application in magnetoelectric devices.
-
Mg doping effect on the magnetic Properties of Y-type hexaferrite Ba0.5Sr1.5Zn2−xMgxFe12O22
Journal of Alloys and Compounds, 2016Co-Authors: Min Zhang, Xiangkai Kong, Zhenfa ZiAbstract:Abstract The microstructure and magnetic Properties of Mg-doped Ba0.5Sr1.5Zn2Fe12O22 hexaferrites synthesized by the solid state method are investigated. All the undoped and doped samples show a sharp Screw Proper spin phase to collinear ferrimagnetic spin phase transition above room temperature, and transition temperature increases distinctly with Mg doping. It is noteworthy that all the samples exhibit another magnetic phase transition at a lower temperature T1, which is associated with the longitudinal conical to the Proper Screw phase transition. The transition temperature T1 can be modulated by varying Mg content, indicating that the longitudinal conical spin phase is stabilized by the Mg-substitution. The saturation magnetization at room temperature increases to a maximum with Mg content x = 0.8 and then decreases with x. The variations of magnetic Properties can be ascribed to the difference in the preferential site for Zn and Mg and different distribution of Fe3+ ions over tetrahedral and octahedral sites. It is worth noting that the range for the intermediate-III phase increases significantly as x increases to 2.0, suggesting that Mg-doped samples may be display field-induced ferroelectric order at temperature close to RT and in wide magnetic-field regions. The room-temperature M-H curves at lower applied field indicate that magnetic-field-induced ferroelectric phase can be stabilized at zero magnetic field by the substitution by Mg2+ for Zn2+. The Mg-doped hexaferrites Ba0.5Sr1.5Zn2Fe12O22 may be potential candidates for applying in magnetoelectric devices.
Shin Nakamura - One of the best experts on this subject based on the ideXlab platform.
-
Mössbauer Study of the Ferroelectric State in Ga-Substituted CuFeO2
Journal of the Physical Society of Japan, 2014Co-Authors: Shin Nakamura, Akio Fuwa, Noriki TeradaAbstract:57Fe Mossbauer spectroscopic measurements have been conducted on CuFe1−xGaxO2 single crystals, in order to investigate the magnetic structures and hyperfine parameters in ferroelectric CuFe0.965Ga0.035O2 and paraelectric CuFeO2. We confirmed that the Mossbauer spectrum at 4.2 K in CuFeO2 is explained by the collinear antiferromagnetic structure with spins along the hexagonal c-axis. In the ferroelectric phase in CuFe0.965Ga0.035O2, the spectrum consists of three magnetic components, where magnetic hyperfine fields distribute in three different directions within the (110) plane. This configuration is not completely consistent with a simple Proper Screw structure with a uniform spin distribution. The quadrupole coupling constants e2qQ/2 are unexpectedly large for both specimens. In the ferroelectric state in CuFe0.965Ga0.035O2, e2qQ/2 becomes noticeably smaller than that in the paraelectric phase in CuFeO2. We discuss the difference in quadrupole coupling constant between the ferroelectric and paraelectric ...
-
Mössbauer study on Y-type hexaferrite Ba_2Mg_2Fe_12O_22
Hyperfine Interactions, 2012Co-Authors: Shin Nakamura, Yorihiko Tsunoda, Akio FuwaAbstract:Mössbauer study on a Y-type hexaferrite Ba_2Mg_2Fe_12O_22 has been conducted by using a single crystal specimen. The spins are in the c-plane down to 60 K. For 18 h _VI site Fe, the quadrupole shifts and the outermost line width change around 195 K, where the transition from ferrimagnetic to Proper Screw spin structure takes place. Below 50 K, the spin reorientation transition to a longitudinal conical structure was also recognized. At 16 K, the spins incline about 15° from the c -plane.
-
Mössbauer study on Y-type hexaferrite Ba 2 Mg 2 Fe 12 O 22
Hyperfine Interactions, 2012Co-Authors: Shin Nakamura, Yorihiko Tsunoda, Akio FuwaAbstract:Mossbauer study on a Y-type hexaferrite Ba2Mg2Fe12O22 has been conducted by using a single crystal specimen. The spins are in the c-plane down to 60 K. For 18h VI site Fe, the quadrupole shifts and the outermost line width change around 195 K, where the transition from ferrimagnetic to Proper Screw spin structure takes place. Below 50 K, the spin reorientation transition to a longitudinal conical structure was also recognized. At 16 K, the spins incline about 15° from the c-plane.
