The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
K. Park - One of the best experts on this subject based on the ideXlab platform.
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fabrication and electrical properties of mn ni co cu si oxides Negative Temperature coefficient thermistors
Journal of the American Ceramic Society, 2005Co-Authors: K. ParkAbstract:The microstructure and electrical properties of Mn-Ni-Co-Cu-Si oxides Negative Temperature coefficient (NTC) thermistors were studied. The as-sintered (Mn 1.62 Ni 0.72 Co 0.57-x Cu x Si 0.09 )O 4 (0≤X≤0.12) and (Mn 1.2 Ni 0.78 Co 0.87-x Cu 0.15 Si x )O 4 (0≤X≤ 0.15) ceramics showed the solid solutions of Mn-Ni-Co-Cu-Si oxides with a cubic spinel structure. The addition of SiO 2 led to an increase in the Temperature coefficient of resistivity. This demonstrates that the SiO 2 addition is desirable for developing highly sensitive NTC thermistors. In addition, the resistivity and the Temperature coefficient of resistivity for (Mn 1.62 Ni 0.72 Co 0.57-x Cu x Si 0.09 )O 4 and (Mn 1.2 Ni 0.78 Co 0.87-x Cu 0.15 Si x )O 4 NTC thermistors were controlled by changing the composition.
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improvement in electrical stability by addition of sio2 in mn1 2ni0 78co0 87 xcu0 15six o4 Negative Temperature coefficient thermistors
Scripta Materialia, 2004Co-Authors: K. ParkAbstract:Abstract The electrical stability of (Mn1.2Ni0.78Co0.87−xCu0.15Six)O4 (0⩽x⩽0.15) Negative Temperature coefficient (NTC) thermistors was studied by measuring the relative resistance change. The resistance change of the thermistors was significantly decreased by the addition of SiO2. It is proposed that the addition of SiO2 is desirable to achieve stable NTC thermistors.
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effect of sio2 addition on the electrical stability of mn2 1 xni0 9six o4 0 x 0 18 Negative Temperature coefficient thermistors
Materials Letters, 2004Co-Authors: K. Park, S J YunAbstract:Abstract The effect of SiO 2 addition on the electrical stability of (Mn 2.1− x Ni 0.9 Si x )O 4 (0≦ x ≦0.18) Negative Temperature coefficient (NTC) thermistors was studied. The grain size decreased significantly with increasing SiO 2 content. The addition of SiO 2 led to a significant decrease in the resistance change of the thermistors, probably due to the grain refinement. It is therefore believed that the addition of SiO 2 is desirable to achieve stable NTC thermistors.
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microstructure and electrical properties of ni1 0mn2 xzrxo4 0 x 1 0 Negative Temperature coefficient thermistors
Materials Science and Engineering B-advanced Functional Solid-state Materials, 2003Co-Authors: K. ParkAbstract:Abstract The effect of the composition on the microstructure and electrical properties of Ni 1.0 Mn 2− x Zr x O 4 (0≤ x ≤1.0) Negative Temperature coefficient (NTC) thermistors was studied. Major phases present in the sintered bodies of Ni 1.0 Mn 2− x Zr x O 4 were the solid solutions of Ni–Mn–Zr oxides with a cubic spinel structure and the ZrO 2 with a tetragonal structure. ZrO 2 was formed by the partial decomposition or incomplete formation of the Ni–Mn–Zr oxides during sintering. The ZrO 2 phase increased with an increase in the amount of added ZrO 2 . The relationship between log resistivity (log ρ ) and the reciprocal of absolute Temperature (1/ T ) of the prepared NTC thermistors was linear, indicative of NTC characteristics. The resistivity, B constant, and activation energy of the thermistors increased with an increase of ZrO 2 content.
J. T. Wang - One of the best experts on this subject based on the ideXlab platform.
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Negative Temperature dependence of recrystallized grain size formulation and experimental confirmation on copper
Materials, 2017Co-Authors: Mohamed Elmasry, Ying Jiang, J. T. WangAbstract:The catalyzing effect on nucleation of recrystallization from existing grains resulting from previous lower Temperature deformation is analyzed, analogous to the size effect of foreign nucleus in heterogeneous nucleation. Analytical formulation of the effective nucleation site for recrystallization leads to a Negative Temperature dependence of recrystallized grain size of metals. Non-isochronal annealing—where annealing time is set just enough for the completion of recrystallization at different Temperatures—is conducted on pure copper after severe plastic deformation. More homogeneous and smaller grains are obtained at higher annealing Temperature. The good fit between analytical and experimental results unveils the intrinsic feature of this Negative Temperature dependence of recrystallized grain size.
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Negative Temperature dependence of recrystallized grain size analytical formulation and experimental confirmation
IOP Conference Series: Materials Science and Engineering, 2017Co-Authors: Mohamed Elmasry, Ying Jiang, J. T. WangAbstract:The catalyzing effect on nucleation of recrystallization from pre-existing grains is analyzed, analogy to the foreign nucleus size effect in heterogeneous nucleation. Analytical formulation of the effective nucleation site for recrystallization leads to a Negative Temperature dependence of recrystallized grain size. Non-isochronal annealing, where annealing time is set just enough for the completion of recrystallization at different Temperature, is conducted on pure copper after severe plastic deformation. More homogeneous and smaller grains are obtained at higher annealing Temperature. The good fitting between analytical and experimental results unveils the intrinsic feature of this Negative Temperature dependence of recrystallized grain size.
Fazle Hussain - One of the best experts on this subject based on the ideXlab platform.
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Reply to ``Comment on `Negative Temperature of vortex motion' ''
Physical review. E Statistical physics plasmas fluids and related interdisciplinary topics, 1993Co-Authors: Victor L. Berdichevsky, Isaak A. Kunin, Fazle HussainAbstract:We respond to the questions raised in the preceding Comment [K. O'Neil and L. J. Campbell, Phys. Rev. A 47, 2966 (1993)]. We explain why our statement ``vortex Temperature is always positive'' is equivalent to the ``opposite'' statement in the Comment: ``vortex Temperature is always Negative,'' and why we viewed the Negative Temperature states as paradoxical. We discuss also the notion of Temperature for the limit case of infinite number of vortices.
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Reply to "Comment on 'Negative Temperature of vortex motion' "
Physical review. A Atomic molecular and optical physics, 1991Co-Authors: Victor L. Berdichevsky, Isaak A. Kunin, Fazle HussainAbstract:We respond to the main points in the preeeding Comment (D. Montgomery, Phys. Rev. A 44, 8437 (1991)), which are the following: (a) For spatially inhomogeneous configurations of point vortices in a box, Negative Temperature occurs and is not a paradox to be resolved. (b) A redefinition of Temperature following early speculation of Gibbs'' does not shed light on the high-energy behavior of point vortices.
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Negative Temperature of vortex motion.
Physical review. A Atomic molecular and optical physics, 1991Co-Authors: Victor L. Berdichevsky, Isaak A. Kunin, Fazle HussainAbstract:It is shown that the well-known Onsager paradox of Negative Temperature of point vortices can be resolved by adopting a proper formula for entropy. We also provide an interpretation of vortex Temperature in terms of the geometry of vortex trajectories.
Mohamed Elmasry - One of the best experts on this subject based on the ideXlab platform.
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Negative Temperature dependence of recrystallized grain size formulation and experimental confirmation on copper
Materials, 2017Co-Authors: Mohamed Elmasry, Ying Jiang, J. T. WangAbstract:The catalyzing effect on nucleation of recrystallization from existing grains resulting from previous lower Temperature deformation is analyzed, analogous to the size effect of foreign nucleus in heterogeneous nucleation. Analytical formulation of the effective nucleation site for recrystallization leads to a Negative Temperature dependence of recrystallized grain size of metals. Non-isochronal annealing—where annealing time is set just enough for the completion of recrystallization at different Temperatures—is conducted on pure copper after severe plastic deformation. More homogeneous and smaller grains are obtained at higher annealing Temperature. The good fit between analytical and experimental results unveils the intrinsic feature of this Negative Temperature dependence of recrystallized grain size.
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Negative Temperature dependence of recrystallized grain size analytical formulation and experimental confirmation
IOP Conference Series: Materials Science and Engineering, 2017Co-Authors: Mohamed Elmasry, Ying Jiang, J. T. WangAbstract:The catalyzing effect on nucleation of recrystallization from pre-existing grains is analyzed, analogy to the foreign nucleus size effect in heterogeneous nucleation. Analytical formulation of the effective nucleation site for recrystallization leads to a Negative Temperature dependence of recrystallized grain size. Non-isochronal annealing, where annealing time is set just enough for the completion of recrystallization at different Temperature, is conducted on pure copper after severe plastic deformation. More homogeneous and smaller grains are obtained at higher annealing Temperature. The good fitting between analytical and experimental results unveils the intrinsic feature of this Negative Temperature dependence of recrystallized grain size.
Victor L. Berdichevsky - One of the best experts on this subject based on the ideXlab platform.
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Reply to ``Comment on `Negative Temperature of vortex motion' ''
Physical review. E Statistical physics plasmas fluids and related interdisciplinary topics, 1993Co-Authors: Victor L. Berdichevsky, Isaak A. Kunin, Fazle HussainAbstract:We respond to the questions raised in the preceding Comment [K. O'Neil and L. J. Campbell, Phys. Rev. A 47, 2966 (1993)]. We explain why our statement ``vortex Temperature is always positive'' is equivalent to the ``opposite'' statement in the Comment: ``vortex Temperature is always Negative,'' and why we viewed the Negative Temperature states as paradoxical. We discuss also the notion of Temperature for the limit case of infinite number of vortices.
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Reply to "Comment on 'Negative Temperature of vortex motion' "
Physical review. A Atomic molecular and optical physics, 1991Co-Authors: Victor L. Berdichevsky, Isaak A. Kunin, Fazle HussainAbstract:We respond to the main points in the preeeding Comment (D. Montgomery, Phys. Rev. A 44, 8437 (1991)), which are the following: (a) For spatially inhomogeneous configurations of point vortices in a box, Negative Temperature occurs and is not a paradox to be resolved. (b) A redefinition of Temperature following early speculation of Gibbs'' does not shed light on the high-energy behavior of point vortices.
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Negative Temperature of vortex motion.
Physical review. A Atomic molecular and optical physics, 1991Co-Authors: Victor L. Berdichevsky, Isaak A. Kunin, Fazle HussainAbstract:It is shown that the well-known Onsager paradox of Negative Temperature of point vortices can be resolved by adopting a proper formula for entropy. We also provide an interpretation of vortex Temperature in terms of the geometry of vortex trajectories.
