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- Ampicillin (1)
- Antiferroelectric Phase Transition Temperature (1)
- Cluster analysis (1)
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- Crystallographical c Axis (1)
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- Dielectric Permittivity (1)
- Dielectric Relaxation (1)
- Electric Modulus (1)
- Ferroelectric-Paraelectric Phase Transition (1)
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- Gordon-Kim Electron Gas Theory (1)
- Hartree-Fock Calculations (1)
- Intermolecular Interactions (1)
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- Multiple regression (1)
- Pair Potentials (1)
- Pattern recognition (1)
- Permittivity Studies (1)
- Pure Ba-doped Bi2Ti4O11 (1)
- Rigid-Ion Model (1)
- Rotataion Nitrite Ions (1)
- Solid NaNO2 (1)
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- TiO6 Octahedra Distortion (1)
Articles 1 - 3 of 3
Full-Text Articles in Physical Sciences and Mathematics
Dielectric Permittivity And Electric Modulus In Bi2ti4o11, Jianjun Liu, Chun-Gang Duan, Wei-Guo Yin, Wai-Ning Mei, Robert W. Smith, John R. Hardy
Dielectric Permittivity And Electric Modulus In Bi2ti4o11, Jianjun Liu, Chun-Gang Duan, Wei-Guo Yin, Wai-Ning Mei, Robert W. Smith, John R. Hardy
Physics Faculty Publications
Frequency and temperature dependences of dielectric permittivity and electric modulus of pure and Ba-doped Bi2Ti4O11 were studied in the ranges of 1021–106 Hz and 2150–350 °C, respectively. We found that the antiferroelectric phase transition temperature of Bi2Ti4O11 decreases with Ba doping. In the permittivity studies, we also observed dielectric relaxation peaks shift to higher temperature with increasing frequency. Furthermore, in the electric modulus formalism, conducting peaks were uncovered above 150 °C in addition to the dielectric relaxation peak. We discussed the mechanisms for the dielectric relaxation and conduction processes based on TiO6 octahedra distortion and a space-charge model.
Molecular Dynamics Simulation Of The Order- Disorder Phase Transition In Solid Nano2, Wei-Guo Yin, Chun-Gang Duan, Wai-Ning Mei, Jianjun Liu, Robert W. Smith, John R. Hardy
Molecular Dynamics Simulation Of The Order- Disorder Phase Transition In Solid Nano2, Wei-Guo Yin, Chun-Gang Duan, Wai-Ning Mei, Jianjun Liu, Robert W. Smith, John R. Hardy
Physics Faculty Publications
We present molecular dynamics simulations of solid NaNO2 using pair potentials with the rigid-ion model. The crystal potential surface is calculated by using an a priori method which integrates the ab initio calculations with the Gordon-Kim electron gas theory. This approach is carefully examined by using different population analysis methods and comparing the intermolecular interactions resulting from this approach with those from the ab initio Hartree-Fock calculations. Our numerics show that the ferroelectric-paraelectric phase transition in solid NaNO2 is triggered by rotation of the nitrite ions around the crystallographical c axis, in agreement with recent x-ray experiments @Gohda et al., …
Utilizing Structure Property Correlations To Predict And Analyze Two Derivatives Of An Ampicillin Homologous Series, C. Malesa, J. Stoddard, Ronald Bartzatt
Utilizing Structure Property Correlations To Predict And Analyze Two Derivatives Of An Ampicillin Homologous Series, C. Malesa, J. Stoddard, Ronald Bartzatt
Chemistry Faculty Publications
Structure Property Correlation methods such as regression analysis and pattern recognition are applied to predict the molecular properties of two members of an ampicillin homologous series. The pentyl and hexyl esters of ampicillin are also evaluated for their similarity to other penicillins by use of multiple regression, contingency tables, cluster analysis, correspondence analysis, self organizing tree algorithms, factor analysis, principal component analysis, box plots, and other graphing methods. Other members of the homologous series include methyl, ethyl, propyl, and butyl esters of ampicillin which have been previously synthesized and tested in tissue culture against Escherichia coli. All of the tested …